Until now it was only possible to use track-sc1/sc2 with "src" which
is the IPv4 source address. Now we can use track-sc1/sc2 with any fetch
as well as any transformation type. It works just like the "stick"
directive.
Samples are automatically converted to the correct types for the table.
Only "tcp-request content" rules may use L7 information, and such information
must already be present when the tracking is set up. For example it becomes
possible to track the IP address passed in the X-Forwarded-For header.
HTTP request processing now also considers tracking from backend rules
because we want to be able to update the counters even when the request
was already parsed and tracked.
Some more controls need to be performed (eg: samples do not distinguish
between L4 and L6).
Both servers and proxies share a common set of parameters for outgoing
connections, and since they're not stored in a similar structure, a lot
of code is duplicated in the connection setup, which is one sensible
area.
Let's first define a common struct for these settings and make use of it.
Next patches will de-duplicate code.
This change also fixes a build breakage that happens when USE_LINUX_TPROXY
is not set but USE_CTTPROXY is set, which seem to be very unlikely
considering that the issue was introduced almost 2 years ago an never
reported.
Sessions using client certs are huge (more than 1 kB) and do not fit
in session cache, or require a huge cache.
In this new implementation sshcachesize set a number of available blocks
instead a number of available sessions.
Each block is large enough (128 bytes) to store a simple session (without
client certs).
Huge sessions will take multiple blocks depending on client certificate size.
Note: some unused code for session sync with remote peers was temporarily
removed.
When the PROXY protocol header is expected and fails, leading to an
abort of the incoming connection, we now emit a log message. If option
dontlognull is set and it was just a port probe, then nothing is logged.
Since the introduction of SSL, it became quite annoying not to get any useful
info in logs about handshake failures. Let's improve reporting for embryonic
sessions by checking a per-connection error code and reporting it into the logs
if an error happens before the session is completely instanciated.
The "dontlognull" option is supported in that if a connection does not talk
before being aborted, nothing will be emitted.
At the moment, only timeouts are considered for SSL and the PROXY protocol,
but next patches will handle more errors.
Commit 9b6700f added "v6only". As suggested by Vincent Bernat, it is
sometimes useful to have the opposite option to force binding to the
two protocols when the system is configured to bind to v6 only by
default. This option does exactly this. v6only still has precedence.
Depending on the content-types and accept-encoding fields, some responses
might or might not be compressed. Let's have a counter of the number of
compressed responses and report it in the stats to help improve compression
usage.
Some cosmetic issues were fixed in the CSV output too (missing commas at the
end).
Commit 0ffde2cc in 1.5-dev13 tried to always disable polling on file
descriptors when errors were encountered. Unfortunately it did not
always succeed in doing so because it relied on detecting polling
changes to disable it. Let's use a dedicated conn_stop_polling()
function that is inconditionally called upon error instead.
This managed to stop a busy loop observed when a health check makes
use of the send-proxy protocol and fails before the connection can
be established.
Commit 24db47e0 tried to improve support for delayed ACK upon connect
but it was incomplete, because checks with the proxy protocol would
always enable polling for data receive and there was no way of
distinguishing data polling and delayed ack.
So we add a distinct delack flag to the connect() function so that
the caller decides whether or not to use a delayed ack regardless
of pending data (eg: when send-proxy is in use). Doing so covers all
combinations of { (check with data), (sendproxy), (smart-connect) }.
Several places got the connection close sequence wrong because it
was not obvious. In practice we always need the same sequence when
aborting, so let's have a common function for this.
The porting of checks to using connections was totally bogus. Some checks
were considered successful as soon as the connection was established,
regardless of any response. Some errors would be triggered upon recv
if polling was enabled for send or if the send channel was shut down.
Now the behaviour is much better. It would be cleaner to perform the
fd_delete() in wake_srv_chk() and to process failures and timeouts
separately, but this is already a good start.
Some server check flag names were not properly choosen and cause
analysis trouble, especially the CHK_RUNNING one which does not
mean that a check is running but that the server is running...
Here's the rename :
CHK_RUNNING -> CHK_PASSED
CHK_ERROR -> CHK_FAILED
It was a bit frustrating to have no idea about the bandwidth saved by
HTTP compression. Now we have per-frontend and per-backend stats. The
stats on the HTTP interface are shown in a hover title in the "bytes out"
column if at least something was fed to the compressor. 3 new columns
appeared in the CSV stats output.
Some users need more than 64 characters to log large cookies. The limit
was set to 63 characters (and not 64 as previously documented). Now it
is possible to change this using the global "tune.http.cookielen" setting
if required.
New option 'maxcompcpuusage' in global section.
Sets the maximum CPU usage HAProxy can reach before stopping the
compression for new requests or decreasing the compression level of
current requests. It works like 'maxcomprate' but with the Idle.
This patch makes changes in the http_response_forward_body state
machine. It checks if the compress algorithm had consumed data before
swapping the temporary and the input buffer. So it prevents null sized
zlib chunks.
global.tune.maxaccept was used for all listeners. This becomes really not
convenient when some listeners are bound to a single process and other ones
are bound to many processes.
Now we change the principle : we count the number of processes a listener
is bound to, and apply the maxaccept either entirely if there is a single
process, or divided by twice the number of processes in order to maintain
fairness.
The default limit has also been increased from 32 to 64 as it appeared that
on small machines, 32 was too low to achieve high connection rates.
The new "cpu-map" directive allows one to assign the CPU sets that
a process is allowed to bind to. This is useful in combination with
the "nbproc" and "bind-process" directives.
The support is implicit on Linux 2.6.28 and above.
This is done by passing the default value to SSLCACHESIZE in sessions.
User can use tune.sslcachesize to change this value.
By default, it is set to 20000 sessions as openssl internal cache size.
Currently, a session entry size is between 592 and 616 bytes depending on the arch.
Instead of storing a couple of (int, ptr) in the struct connection
and the struct session, we use a different method : we only store a
pointer to an integer which is stored inside the target object and
which contains a unique type identifier. That way, the pointer allows
us to retrieve the object type (by dereferencing it) and the object's
address (by computing the displacement in the target structure). The
NULL pointer always corresponds to OBJ_TYPE_NONE.
This reduces the size of the connection and session structs. It also
simplifies target assignment and compare.
In order to improve the generated code, we try to put the obj_type
element at the beginning of all the structs (listener, server, proxy,
si_applet), so that the original and target pointers are always equal.
A lot of code was touched by massive replaces, but the changes are not
that important.
Before connections were introduced, it was possible to connect an
external task to a stream interface. However it was left as an
exercise for the brave implementer to find how that ought to be
done.
The feature was broken since the introduction of connections and
was never fixed since due to lack of users. Better remove this dead
code now.
Hijackers were functions designed to inject data into channels in the
distant past. They became unused around 1.3.16, and since there has
not been any user of this mechanism to date, it's uncertain whether
the mechanism still works (and it's not really useful anymore). So
better remove it as well as the pointer it uses in the channel struct.
Some servers are not totally HTTP-compliant when it comes to parsing the
Connection header. This is particularly true with WebSocket where it happens
from time to time that a server doesn't support having a "close" token along
with the "Upgrade" token in the Connection header. This broken behaviour has
also been noticed on some clients though the problem is less frequent on the
response path.
Sometimes the workaround consists in enabling "option http-pretend-keepalive"
to leave the request Connection header untouched, but this is not always the
most convenient solution. This patch introduces a new solution : haproxy now
also looks for the "Upgrade" token in the Connection header and if it finds
it, then it refrains from adding any other token to the Connection header
(though "keep-alive" and "close" may still be removed if found). The same is
done for the response headers.
This way, WebSocket much with less changes even when facing non-compliant
clients or servers. At least it fixes the DISCONNECT issue that was seen
on the websocket.org test.
Note that haproxy does not change its internal mode, it just refrains from
adding new tokens to the connection header.
Now that all pollers make use of speculative I/O, there is no point
having two epoll implementations, so replace epoll with the sepoll code
and remove sepoll which has just become the standard epoll method.
si_fd() is not used a lot, and breaks builds on OpenBSD 5.2 which
defines this name for its own purpose. It's easy enough to remove
this one-liner function, so let's do it.
ev_sepoll already provides everything needed to manage FD events
by only manipulating the speculative I/O list. Nothing there is
sepoll-specific so move all this to fd.
This patch adds input and output rate calcutation on the HTTP compresion
feature.
Compression can be limited with a maximum rate value in kilobytes per
second. The rate is set with the global 'maxcomprate' option. You can
change this value dynamicaly with 'set rate-limit http-compression
global' on the UNIX socket.
At the moment sepoll is not 100% event-driven, because a call to fd_set()
on an event which is already being polled will not change its state.
This causes issues with OpenSSL because if some I/O processing is interrupted
after clearing the I/O event (eg: read all data from a socket, can't put it
all into the buffer), then there is no way to call the SSL_read() again once
the buffer releases some space.
The only real solution is to go 100% event-driven. The principle is to use
the spec list as an event cache and that each time an I/O event is reported
by epoll_wait(), this event is automatically scheduled for addition to the
spec list for future calls until the consumer explicitly asks for polling
or stopping.
Doing this is a bit tricky because sepoll used to provide a substantial
number of optimizations such as event merging. These optimizations have
been maintained : a dedicated update list is affected when events change,
but not the event list, so that updates may cancel themselves without any
side effect such as displacing events. A specific case was considered for
handling newly created FDs as soon as they are detected from within the
poll loop. This ensures that their read or write operation will always be
attempted as soon as possible, thus reducing the number of poll loops and
process_session wakeups. This is especially true for newly accepted fds
which immediately perform their first recv() call.
Two new flags were added to the fdtab[] struct to tag the fact that a file
descriptor already exists in the update list. One flag indicates that a
file descriptor is new and has just been created (fdtab[].new) and the other
one indicates that a file descriptor is already referenced by the update list
(fdtab[].updated). Even if the FD state changes during operations or if the
fd is closed and replaced, it's not an issue because the update flag remains
and is easily spotted during list walks. The flag must absolutely reflect the
presence of the fd in the update list in order to avoid overflowing the update
list with more events than there are distinct fds.
Note that this change also recovers the small performance loss introduced
by its connection counter-part and goes even beyond.
This is the first step of a series of changes aiming at making the
polling totally event-driven. This first change consists in only
remembering at the connection level whether an FD was enabled or not,
regardless of the fact it was being polled or cached. From now on, an
EAGAIN will always be considered as a change so that the pollers are
able to manage a cache and to flush it based on such events. One of
the noticeable effect is that conn_fd_handler() is called once more
per session (6 instead of 5 min) but other update functions are less
called.
Note that the performance loss caused by this change at the moment is
quite significant, around 2.5%, but the change is needed to have SSL
working correctly in all situations, even when data were read from the
socket and stored in the invisible cache, waiting for some room in the
channel's buffer.
With the global maxzlibmem option, you are able ton control the maximum
amount of RAM usable for HTTP compression.
A test is done before each zlib allocation, if the there isn't available
memory, the test fail and so the zlib initialization, so data won't be
compressed.
Don't use the zlib allocator anymore, 5 pools are used for the zlib
compression. Their sizes depends of the window size and the memLevel in
deflateInit2.
The window size and the memlevel of the zlib are now configurable using
global options tune.zlib.memlevel and tune.zlib.windowsize.
It affects the memory consumption of the zlib.
The build was dependent of the zlib.h header, regardless of the USE_ZLIB
option. The fix consists of several #ifdef in the source code.
It removes the overhead of the zstream structure in the session when you
don't use the option.
It is stupid to loop over ->snd_buf() because the snd_buf() itself already
loops and stops when system buffers are full. But looping again onto it,
we lose the information of the full buffers and perform one useless syscall.
Furthermore, this causes issues when dealing with large uploads while waiting
for a connection to establish, as it can report a server reject of some data
as a connection abort, which is wrong.
1.4 does not have this issue as it loops maximum twice (once for each buffer
half) and exists as soon as system buffers are full. So no backport is needed.
Keys are copied from samples to stick_table_key. If a key is larger
than the stick_table_key, we have an overflow. In pratice it does not
happen because it requires :
1) a configuration with tune.bufsize larger than BUFSIZE (common)
2) a stick-table configured with keys strictly larger than buffers
3) extraction of data larger than BUFSIZE (eg: using payload())
Points 2 and 3 don't make any sense for a real world configuration. That
said the issue needs be fixed. The solution consists in allocating it the
same size as the global buffer size, just like the samples. This fixes the
issue.
Sample conversions rely on two alternative buffers which were previously
allocated as static bufs of size BUFSIZE. Now they're initialized to the
global buffer size. It was the same for HTTP authentication. Note that it
seems that none of them was prone to any mistake when dealing with the
buffer size, but better stay on the safe side by maintaining the old
assumption that a trash buffer is always "large enough".
The trash is used everywhere to store the results of temporary strings
built out of s(n)printf, or as a storage for a chunk when chunks are
needed.
Using global.tune.bufsize is not the most convenient thing either.
So let's replace trash with a chunk and directly use it as such. We can
then use trash.size as the natural way to get its size, and get rid of
many intermediary chunks that were previously used.
The patch is huge because it touches many areas but it makes the code
a lot more clear and even outlines places where trash was used without
being that obvious.
This function's naming was misleading as it is used to append data
at the end of a string, causing some surprizes when used for the
first time!
Add a chunk_printf() function which does what its name suggests.
This is a first step in avoiding to constantly reinitialize chunks.
It replaces the old chunk_reset() which was not properly named as it
used to drop everything and was only used by chunk_destroy(). It has
been renamed chunk_drop().
We will need to be able to switch server connections on a session and
to keep idle connections. In order to achieve this, the preliminary
requirement is that the connections can survive the session and be
detached from them.
Right now they're still allocated at exactly the same place, so when
there is a session, there are always 2 connections. We could soon
improve on this by allocating the outgoing connection only during a
connect().
This current patch touches a lot of code and intentionally does not
change any functionnality. Performance tests show no regression (even
a very minor improvement). The doc has not yet been updated.
This commit introduces HTTP compression using the zlib library.
http_response_forward_body has been modified to call the compression
functions.
This feature includes 3 algorithms: identity, gzip and deflate:
* identity: this is mostly for debugging, and it was useful for
developping the compression feature. With Content-Length in input, it
is making each chunk with the data available in the current buffer.
With chunks in input, it is rechunking, the output chunks will be
bigger or smaller depending of the size of the input chunk and the
size of the buffer. Identity does not apply any change on data.
* gzip: same as identity, but applying a gzip compression. The data
are deflated using the Z_NO_FLUSH flag in zlib. When there is no more
data in the input buffer, it flushes the data in the output buffer
(Z_SYNC_FLUSH). At the end of data, when it receives the last chunk in
input, or when there is no more data to read, it writes the end of
data with Z_FINISH and the ending chunk.
* deflate: same as gzip, but with deflate algorithm and zlib format.
Note that this algorithm has ambiguous support on many browsers and
no support at all from recent ones. It is strongly recommended not
to use it for anything else than experimentation.
You can't choose the compression ratio at the moment, it will be set to
Z_BEST_SPEED (1), as tests have shown very little benefit in terms of
compression ration when going above for HTML contents, at the cost of
a massive CPU impact.
Compression will be activated depending of the Accept-Encoding request
header. With identity, it does not take care of that header.
To build HAProxy with zlib support, use USE_ZLIB=1 in the make
parameters.
This work was initially started by David Du Colombier at Exceliance.
This state's name is confusing as it is only used with chunked encoding
and makes newcomers think it's also related to the content-length. Let's
call it CHUNK_CRLF to clear any doubt on this.
This tiny function was not inlined because initially not much used.
However it's been used un the chunk parser for a while and it became
one of the most CPU-cycle eater there. By inlining it, the chunk parser
speed was increased by 74 %. We're almost 3 times faster than original
with just the last 4 commits.
Most calls to channel_forward() are performed with short byte counts and
are already optimized in channel_forward() taking just a few instructions.
Thus it's a waste of CPU cycles to call a function for this, let's just
inline the short byte count case and fall back to the common one for
remaining situations.
Doing so has increased the chunked encoding parser's performance by 12% !
ACL and sample fetches use args list and it is really not convenient to
check for null args everywhere. Now for empty args we pass a constant
list of end of lists. It will allow us to remove many useless checks.
It's sometimes needed to be able to compare a zero-terminated string with a
chunk, so we now have two functions to do that, one strcmp() equivalent and
one strcasecmp() equivalent.
The ssl_npn match could not work by itself because clients do not use
the NPN extension unless the server advertises the protocols it supports.
Thanks to Simone Bordet for the explanations on how to get it right.
The struct target contains one int and one pointer, causing it to be
64-bit aligned on 64-bit platforms. By marking it "packed", we can
save 8 bytes in struct connection and as many in struct session on
such platforms.
This field was used to trace precisely where a session was terminated
but it did not survive code rearchitecture and was not used at all
anymore. Let's get rid of it.
Now that the buffer is moved out of the channel, it is possible to move
the pointer earlier in the struct and reorder some fields. This new
ordering improves overall performance by 2%, mainly saved in the HTTP
parsers and data transfers.
With this commit, we now separate the channel from the buffer. This will
allow us to replace buffers on the fly without touching the channel. Since
nobody is supposed to keep a reference to a buffer anymore, doing so is not
a problem and will also permit some copy-less data manipulation.
Interestingly, these changes have shown a 2% performance increase on some
workloads, probably due to a better cache placement of data.
These two new log-format tags report the SSL protocol version (%sslv) and the
SSL ciphers (%sslc) used for the connection with the client. For instance, to
append these information just after the client's IP/port address information
on an HTTP log line, use the following configuration :
log-format %Ci:%Cp\ %sslv:%sslc\ [%t]\ %ft\ %b/%s\ %Tq/%Tw/%Tc/%Tr/%Tt\ %st\ %B\ %cc\ \ %cs\ %tsc\ %ac/%fc/%bc/%sc/%rc\ %sq/%bq\ %hr\ %hs\ %{+Q}r
It will report a line such as the following one :
Oct 12 20:47:30 haproxy[9643]: 127.0.0.1:43602 TLSv1:AES-SHA [12/Oct/2012:20:47:30.303] stick2~ stick2/s1 7/0/12/0/19 200 145 - - ---- 0/0/0/0/0 0/0 "GET /?t=0 HTTP/1.0"
This flag will have to be set on log tags which require transport layer
information. They will prevent the conn_xprt_close() call from releasing
the transport layer too early.
When we start logging SSL information, we need the SSL struct to be
present even past the conn_xprt_close() call. In order to achieve this,
we should use refcounting on the connection and the transport layer. At
the moment it's not worth using plain refcounting as only the logs require
this, so instead of real refcounting we just use a flag which will be set
by the log subsystem when SSL data need to be logged.
What happens then is that the xprt->close() call is ignored and the
transport layer is closed again during session_free(), after the log
line is emitted.
When calling conn_xprt_close(), we always clear the transport pointer
so that all transport layers leave the connection in the same state after
a close. This will also make it safer and cheaper to call conn_xprt_close()
multiple times if needed.
Until now it was not possible to know from the logs whether the incoming
connection was made over SSL or not. In order to address this in the existing
log formats, a new log format %ft was introduced, to log the frontend's name
suffixed with its transport layer. The only transport layer in use right now
is '~' for SSL, so that existing log formats for non-SSL traffic are not
affected at all, and SSL log formats have the frontend's name suffixed with
'~'.
The TCP, HTTP and CLF log format now use %ft instead of %f. This does not
affect existing log formats which still make use of %f however.
It now becomes possible to verify the server's certificate using the "verify"
directive. This one only supports "none" and "required", as it does not make
much sense to also support "optional" here.
Just like with the "bind" lines, we'll switch the "server" line
parsing to keyword registration. The code is essentially the same
as for bind keywords, with minor changes such as support for the
default-server keywords and support for variable argument count.
On Linux, accept4() does the same as accept() except that it allows
the caller to specify some flags to set on the resulting socket. We
use this to set the O_NONBLOCK flag and thus to save one fcntl()
call in each connection. The effect is a small performance gain of
around 1%.
The option is automatically enabled when target linux2628 is set, or
when the USE_ACCEPT4 Makefile variable is set. If the libc is too old
to provide the equivalent function, this is automatically detected and
our own function is used instead. In any case it is possible to force
the use of our implementation with USE_MY_ACCEPT4.
Baptiste Assmann reported a bug causing a crash on recent versions when
sticking rules were set on layer 7 in a TCP proxy. The bug is easier to
reproduce with the "defer-accept" option on the "bind" line in order to
have some contents to parse when the connection is accepted. The issue
is that the acl_prefetch_http() function called from HTTP fetches relies
on hdr_idx to be preinitialized, which is not the case if there is no L7
ACL.
The solution consists in adding a new SMP_CAP_L7 flag to fetches to indicate
that they are expected to work on L7 data, so that the proxy knows that the
hdr_idx has to be initialized. This is already how ACL and HTTP mode are
handled.
The bug was present since 1.5-dev9.
These ones are used to set the default ciphers suite on "bind" lines and
"server" lines respectively, instead of using OpenSSL's defaults. These
are probably mainly useful for distro packagers.
When health checks are configured on a server which has the send-proxy
directive and no "port" nor "addr" settings, the health check connections
will automatically use the PROXY protocol. If "port" or "addr" are set,
the "check-send-proxy" directive may be used to force the protocol.
Since it's possible for the checks to use a different protocol or transport layer
than the prod traffic, we need to have them referenced in the server. The
SSL checks are not enabled yet, but the transport layers are completely used.
Till now the request was made in the trash and sent to the network at
once, and the response was read into a preallocated char[]. Now we
allocate a full buffer for both the request and the response, and make
use of it.
Some of the operations will probably be replaced later with buffer macros
but the point was to ensure we could migrate to use the data layers soon.
One nice improvement caused by this change is that requests are now formed
at the beginning of the check and may safely be sent in multiple chunks if
needed.
The health checks in the servers are becoming a real mess, move them
into their own subsection. We'll soon need to have a struct buffer to
replace the char * as well as check-specific protocol and transport
layers.
This callback sends a PROXY protocol line on the outgoing connection,
with the local and remote endpoint information. This is used for local
connections (eg: health checks) where the other end needs to have a
valid address and no connection is relayed.
It was previously in frontend.c but there is no reason for this anymore
considering that all the information involved is in the connection itself
only. Theorically this should be in the socket layer but we don't have
this yet.
We absolutely want to disable FD polling after an error is detected,
otherwise the data layer has to do it and it's far from being obvious
at these layers.
The way we did it was a bit tricky in conn_update_*_polling and
conn_*_polling_changes. However it has almost no impact on performance
and code size both for the fast and slow path.
We'll now be able to remove some flag updates in the stream interface.
Just like ->init(), ->wake() may now be used to return an error and
abort the connection. Currently this is not used but will be with
embryonic sessions.
We now check the connection flags for changes in order not to call the
data->wake callback when there is no activity. Activity means a change
on any of the CO_FL_*_SH, CO_FL_ERROR, CO_FL_CONNECTED, CO_FL_WAIT_CONN*
flags, as well as a call to data->recv or data->send.
The connection flags have progressively been added one after the other
and were not very well organized. Some of them are often used together
and a number of operations are performed on the DATA/SOCK ENA/POL flags.
Thus, they have been reorganized so that flags that work together are
close to each other (allows immediate operands on ARM) and that polling
changes can be detected with fewer operations using a simple shift and
xor. The handshakes are now the last ones so that it will be easier to
add new ones after without risking a collision. All activity-related
flags are also grouped together.
The generic data-layer init callback is now used after the transport
layer is complete and before calling the data layer recv/send callbacks.
This allows the session to switch from the embryonic session data layer
to the complete stream interface data layer, by making conn_session_complete()
the data layer's init callback.
It sill looks awkwards that the init() callback must be used opon error,
but except by adding yet another one, it does not seem to be mergeable
into another function (eg: it should probably not be merged with ->wake
to avoid unneeded calls during the handshake, though semantically that
would make sense).
Instead of calling conn_notify_si() from the connection handler, we
now call data->wake(), which will allow us to use a different callback
with health checks.
Note that we still rely on a flag in order to decide whether or not
to call this function. The reason is that with embryonic sessions,
the callback is already initialized to si_conn_cb without the flag,
and we can't call the SI notify function in the leave path before
the stream interface is initialized.
This issue should be addressed by involving a different data_cb for
embryonic sessions and for stream interfaces, that would be changed
during session_complete() for the final data_cb.
Now conn->data will designate the data layer which is the client for
the transport layer. In practice it's the stream interface and will
soon also be the health checks.
While working on the changes required to make the health checks use the
new connections, it started to become obvious that some naming was not
logical at all in the connections. Specifically, it is not logical to
call the "data layer" the layer which is in charge for all the handshake
and which does not yet provide a data layer once established until a
session has allocated all the required buffers.
In fact, it's more a transport layer, which makes much more sense. The
transport layer offers a medium on which data can transit, and it offers
the functions to move these data when the upper layer requests this. And
it is the upper layer which iterates over the transport layer's functions
to move data which should be called the data layer.
The use case where it's obvious is with embryonic sessions : an incoming
SSL connection is accepted. Only the connection is allocated, not the
buffers nor stream interface, etc... The connection handles the SSL
handshake by itself. Once this handshake is complete, we can't use the
data functions because the buffers and stream interface are not there
yet. Hence we have to first call a specific function to complete the
session initialization, after which we'll be able to use the data
functions. This clearly proves that SSL here is only a transport layer
and that the stream interface constitutes the data layer.
A similar change will be performed to rename app_cb => data, but the
two could not be in the same commit for obvious reasons.
Each proxy contains a reference to the original config file and line
number where it was declared. The pointer used is just a reference to
the one passed to the function instead of being duplicated. The effect
is that it is not valid anymore at the end of the parsing and that all
proxies will be enumerated as coming from the same file on some late
configuration errors. This may happen for exmaple when reporting SSL
certificate issues.
By copying using strdup(), we avoid this issue.
1.4 has the same issue, though no report of the proxy file name is done
out of the config section. Anyway a backport is recommended to ease
post-mortem analysis.
Herv Commowick reported an issue : haproxy dies in a segfault during a
soft restart if it tries to pause a disabled proxy. This is because disabled
proxies have no management task so we must not wake the task up. This could
easily remain unnoticed since the old process was expected to go away, so
having it go away faster was not really troubling. However, with sync peers,
it is obvious that there is no peer sync during this reload.
This issue has been introduced in 1.5-dev7 with the removal of the
maintain_proxies() function. No backport is needed.
Disables the stateless session resumption (RFC 5077 TLS Ticket extension)
and force to use stateful session resumption.
Stateless session resumption is more expensive in CPU usage.
This is because "notlsv1" used to disable TLSv1.0 only and had no effect
on v1.1/v1.2. so better have an option for each version. This applies both
to "bind" and "server" statements.
It removes dependencies with futex or mutex but ssl performances decrease
using nbproc > 1 because switching process force session renegotiation.
This can be useful on small systems which never intend to run in multi-process
mode.
We don't needa to lock the memory when there is a single process. This can
make a difference on small systems where locking is much more expensive than
just a test.
Allow to ignore some verify errors and to let them pass the handshake.
Add option 'crt-ignore-err <list>'
Ignore verify errors at depth == 0 (client certificate)
<list> is string 'all' or a comma separated list of verify error IDs
(see http://www.openssl.org/docs/apps/verify.html)
Add option 'ca-ignore-err <list>'
Same as 'crt-ignore-err' for all depths > 0 (CA chain certs)
Ex ignore all errors on CA and expired or not-yet-valid errors
on client certificate:
bind 0.0.0.0:443 ssl crt crt.pem verify required
cafile ca.pem ca-ignore-err all crt-ignore-err 10,9
Add keyword 'verify' on bind:
'verify none': authentication disabled (default)
'verify optional': accept connection without certificate
and process a verify if the client sent a certificate
'verify required': reject connection without certificate
and process a verify if the client send a certificate
Add keyword 'cafile' on bind:
'cafile <path>' path to a client CA file used to verify.
'crlfile <path>' path to a client CRL file used to verify.
This will be needed to find the stream interface from the connection
once they're detached, but in the more immediate term, we'll need this
for health checks since they don't use a stream interface.
Now the stats socket is allocated when the 'stats socket' line is parsed,
and assigned using the standard str2listener(). This has two effects :
- more than one stats socket can now be declared
- stats socket now support protocols other than UNIX
The next step is to remove the duplicate bind config parsing.
Alex Markham reported and diagnosed a bug appearing on 1.5-dev11,
causing a crash on x86_64 when header hashing is used. The cause is
a missing (int) cast causing a negative offset to appear positive
and the resulting pointer to go out of bounds.
The crash is not possible anymore since 1.5-dev12 because a second
bug caused the negative sign to disappear so the pointer is always
within range but always wrong, so balance hdr() never works anymore.
This fix restores the correct behaviour and ensures the sign is
correct.
Unix permissions are per-bind configuration line and not per listener,
so let's concretize this in the way the config is stored. This avoids
some unneeded loops to set permissions on all listeners.
The access level is not part of the unix perms so it has been moved
away. Once we can use str2listener() to set all listener addresses,
we'll have a bind keyword parser for this one.
Navigating through listeners was very inconvenient and error-prone. Not to
mention that listeners were linked in reverse order and reverted afterwards.
In order to definitely get rid of these issues, we now do the following :
- frontends have a dual-linked list of bind_conf
- frontends have a dual-linked list of listeners
- bind_conf have a dual-linked list of listeners
- listeners have a pointer to their bind_conf
This way we can now navigate from anywhere to anywhere and always find the
proper bind_conf for a given listener, as well as find the list of listeners
for a current bind_conf.
When an unknown "bind" keyword is detected, dump the list of all
registered keywords. Unsupported default alternatives are also reported
as "not supported".
Registering new SSL bind keywords was not particularly handy as it required
many #ifdef in cfgparse.c. Now the code has moved to ssl_sock.c which calls
a register function for all the keywords.
Error reporting was also improved by this move, because the called functions
build an error message using memprintf(), which can span multiple lines if
needed, and each of these errors will be displayed indented in the context of
the bind line being processed. This is important when dealing with certificate
directories which can report multiple errors.
With the arrival of SSL, the "bind" keyword has received even more options,
all of which are processed in cfgparse in a cumbersome way. So it's time to
let modules register their own bind options. This is done very similarly to
the ACLs with a small difference in that we make the difference between an
unknown option and a known, unimplemented option.
Some settings need to be merged per-bind config line and are not necessarily
SSL-specific. It becomes quite inconvenient to have this ssl_conf SSL-specific,
so let's replace it with something more generic.
Bind parsers may return multiple errors, so let's make use of a new function
to re-indent multi-line error messages so that they're all reported in their
context.
A side effect of this change is that the "ssl" keyword on "bind" lines is now
just a boolean and that "crt" is needed to designate certificate files or
directories.
Note that much refcounting was needed to have the free() work correctly due to
the number of cert aliases which can make a context be shared by multiple names.
SSL config holds many parameters which are per bind line and not per
listener. Let's use a per-bind line config instead of having it
replicated for each listener.
At the moment we only do this for the SSL part but this should probably
evolved to handle more of the configuration and maybe even the state per
bind line.
SSL connections take a huge amount of memory, and unfortunately openssl
does not check malloc() returns and easily segfaults when too many
connections are used.
The only solution against this is to provide a global maxsslconn setting
to reject SSL connections above the limit in order to avoid reaching
unsafe limits.
I wrote a small path to add the SSL_OP_CIPHER_SERVER_PREFERENCE OpenSSL option
to frontend, if the 'prefer-server-ciphers' keyword is set.
Example :
bind 10.11.12.13 ssl /etc/haproxy/ssl/cert.pem ciphers RC4:HIGH:!aNULL:!MD5 prefer-server-ciphers
This option mitigate the effect of the BEAST Attack (as I understand), and it
equivalent to :
- Apache HTTPd SSLHonorCipherOrder option.
- Nginx ssl_prefer_server_ciphers option.
[WT: added a test for the support of the option]
This is aimed at disabling SSLv3 and TLSv1 respectively. SSLv2 is always
disabled. This can be used in some situations where one version looks more
suitable than the other.
This SSL session cache was developped at Exceliance and is the same that
was proposed for stunnel and stud. It makes use of a shared memory area
between the processes so that sessions can be handled by any process. It
is only useful when haproxy runs with nbproc > 1, but it does not hurt
performance at all with nbproc = 1. The aim is to totally replace OpenSSL's
internal cache.
The cache is optimized for Linux >= 2.6 and specifically for x86 platforms.
On Linux/x86, it makes use of futexes for inter-process locking, with some
x86 assembly for the locked instructions. On other architectures, GCC
builtins are used instead, which are available starting from gcc 4.1.
On other operating systems, the locks fall back to pthread mutexes so
libpthread is automatically linked. It is not recommended since pthreads
are much slower than futexes. The lib is only linked if SSL is enabled.
CVE-2009-3555 suggests that client-initiated renegociation should be
prevented in the middle of data. The workaround here consists in having
the SSL layer notify our callback about a handshake occurring, which in
turn causes the connection to be marked in the error state if it was
already considered established (which means if a previous handshake was
completed). The result is that the connection with the client is immediately
aborted and any pending data are dropped.
This option currently takes no option and simply turns SSL on for all
connections going to the server. It is likely that more options will
be needed in the future.
This data layer supports socket-to-buffer and buffer-to-socket operations.
No sock-to-pipe nor pipe-to-sock functions are provided, since splicing does
not provide any benefit with data transformation. At best it could save a
memcpy() and avoid keeping a buffer allocated but that does not seem very
useful.
An init function and a close function are provided because the SSL context
needs to be allocated/freed.
A data-layer shutw() function is also provided because upon successful
shutdown, we want to store the SSL context in the cache in order to reuse
it for future connections and avoid a new key generation.
The handshake function is directly called from the connection handler.
At this point it is not certain whether this will remain this way or
if a new ->handshake callback will be added to the data layer so that
the connection handler doesn't care about SSL.
The sock-to-buf and buf-to-sock functions are all capable of enabling
the SSL handshake at any time. This also implies polling in the opposite
direction to what was expected. The upper layers must take that into
account (it is OK right now with the stream interface).
It appears that fd.h includes a number of unneeded files and was
included from standard.h, and as such served as an intermediary
to provide almost everything to everyone.
By removing its useless includes, a long dependency chain broke
but could easily be fixed.
The "spec" sub-struct was using 8 bytes for only 5 needed. There is no
reason to keep it as a struct, it doesn't bring any value. By flattening
it, we can merge the single byte with the next single byte, resulting in
an immediate saving of 4 bytes (20%). Interestingly, tests have shown a
steady performance gain of 0.6% after this change, which can possibly be
attributed to a more cache-line friendly struct.
These flags were added for TCP_CORK. They were only set at various places
but never checked by any user since TCP_CORK was replaced with MSG_MORE.
Simply get rid of this now.
I/O handlers now all use __conn_{sock,data}_{stop,poll,want}_* instead
of returning dummy flags. The code has become slightly simpler because
some tricks such as the MIN_RET_FOR_READ_LOOP are not needed anymore,
and the data handlers which switch to a handshake handler do not need
to disable themselves anymore.
Polling flags were set for data and sock layer, but while this does make
sense for the ENA flag, it does not for the POL flag which translates the
detection of an EAGAIN condition. So now we remove the {DATA,SOCK}_POL*
flags and instead introduce two new layer-independant flags (WANT_RD and
WANT_WR). These flags are only set when an EAGAIN is encountered so that
polling can be enabled.
In order for these flags to have any meaning they are not persistent and
have to be cleared by the connection handler before calling the I/O and
data callbacks. For this reason, changes detection has been slightly
improved. Instead of comparing the WANT_* flags with CURR_*_POL, we only
check if the ENA status changes, or if the polling appears, since we don't
want to detect the useless poll to ena transition. Tests show that this
has eliminated one useless call to __fd_clr().
Finally the conn_set_polling() function which was becoming complex and
required complex operations from the caller was split in two and replaced
its two only callers (conn_update_data_polling and conn_update_sock_polling).
The two functions are now much smaller due to the less complex conditions.
Note that it would be possible to re-merge them and only pass a mask but
this does not appear much interesting.
The PROXY protocol is now decoded in the connection before other
handshakes. This means that it may be extracted from a TCP stream
before SSL is decoded from this stream.
When an incoming connection request is accepted, a connection
structure is needed to store its state. However we don't want to
fully initialize a session until the data layer is about to be
ready.
As long as the connection is physically stored into the session,
it's not easy to split both allocations.
As such, we only initialize the minimum requirements of a session,
which results in what we call an embryonic session. Then once the
data layer is ready, we can complete the function's initialization.
Doing so avoids buffers allocation and ensures that a session only
sees ready connections.
The frontend's client timeout is used as the handshake timeout. It
is likely that another timeout will be used in the future.
SSL need to initialize the data layer before proceeding with data. At
the moment, this data layer is automatically initialized from itself,
which will not be possible once we extract connection from sessions
since we'll only create the data layer once the handshake is finished.
So let's have the application layer initialize the data layer before
using it.
Make it more obvious that this function does not depend on any knowledge
of the session. This is important to plan for TCP rules that can run on
connection without any initialized session yet.
The last uses of the stream interfaces were in tcp_connect_server() and
could easily and more appropriately be moved to its callers, si_connect()
and connect_server(), making a lot more sense.
Now the function should theorically be usable for health checks.
It also appears more obvious that the file is split into two distinct
parts :
- the protocol layer used at the connection level
- the tcp analysers executing tcp-* rules and their samples/acls.
These ones are implicitly handled by the connection's data layer, no need
to rely on them anymore and reaching them maintains undesired dependences
on stream-interface.
We need to have the source and destination addresses in the connection.
They were lying in the stream interface so let's move them. The flags
SI_FL_FROM_SET and SI_FL_TO_SET have been moved as well.
It's worth noting that tcp_connect_server() almost does not use the
stream interface anymore except for a few flags.
It has been identified that once we detach the connection from the SI,
it will probably be needed to keep a copy of the server-side addresses
in the SI just for logging purposes. This has not been implemented right
now though.
This is a massive rename of most functions which should make use of the
word "channel" instead of the word "buffer" in their names.
In concerns the following ones (new names) :
unsigned long long channel_forward(struct channel *buf, unsigned long long bytes);
static inline void channel_init(struct channel *buf)
static inline int channel_input_closed(struct channel *buf)
static inline int channel_output_closed(struct channel *buf)
static inline void channel_check_timeouts(struct channel *b)
static inline void channel_erase(struct channel *buf)
static inline void channel_shutr_now(struct channel *buf)
static inline void channel_shutw_now(struct channel *buf)
static inline void channel_abort(struct channel *buf)
static inline void channel_stop_hijacker(struct channel *buf)
static inline void channel_auto_connect(struct channel *buf)
static inline void channel_dont_connect(struct channel *buf)
static inline void channel_auto_close(struct channel *buf)
static inline void channel_dont_close(struct channel *buf)
static inline void channel_auto_read(struct channel *buf)
static inline void channel_dont_read(struct channel *buf)
unsigned long long channel_forward(struct channel *buf, unsigned long long bytes)
Some functions provided by channel.[ch] have kept their "buffer" name because
they are really designed to act on the buffer according to some information
gathered from the channel. They have been moved together to the same place in
the file for better readability but they were not changed at all.
The "buffer" memory pool was also renamed "channel".
Get rid of these confusing BF_* flags. Now channel naming should clearly
be used everywhere appropriate.
No code was changed, only a renaming was performed. The comments about
channel operations was updated.
These functions do not depend on the channel flags anymore thus they're
much better suited to be used on plain buffers. Move them from channel
to buffer.
This is similar to the recent removal of BF_OUT_EMPTY. This flag was very
problematic because it relies on permanently changing information such as the
to_forward value, so it had to be updated upon every change to the buffers.
Previous patch already got rid of its users.
One part of the change is sensible : the flag was also part of BF_MASK_STATIC,
which is used by process_session() to rescan all analysers in case the flag's
status changes. At first glance, none of the analysers seems to change its
mind base on this flag when it is subject to change, so it seems fine not to
add variation checks here. Otherwise it's possible that checking the buffer's
input and output is more reliable than checking the flag's replacement.
This flag was very problematic because it was composite in that both changes
to the pipe or to the buffer had to cause this flag to be updated, which is
not always simple (eg: there may not even be a channel attached to a buffer
at all).
There were not that many users of this flags, mostly setters. So the flag got
replaced with a macro which reports whether the channel is empty or not, by
checking both the pipe and the buffer.
One part of the change is sensible : the flag was also part of BF_MASK_STATIC,
which is used by process_session() to rescan all analysers in case the flag's
status changes. At first glance, none of the analysers seems to change its
mind base on this flag when it is subject to change, so it seems fine not to
add variation checks here. Otherwise it's possible that checking the buffer's
output size is more useful than checking the flag's replacement.
Some parts of the sock_ops structure were only used by the stream
interface and have been moved into si_ops. Some of them were callbacks
to the stream interface from the connection and have been moved into
app_cp as they're the application seen from the connection (later,
health-checks will need to use them). The rest has moved to data_ops.
Normally at this point the connection could live without knowing about
stream interfaces at all.
The splicing is now provided by the data-layer rcv_pipe/snd_pipe functions
which in turn are called by the stream interface's recv and send callbacks.
The presence of the rcv_pipe/snd_pipe functions is used to attest support
for splicing at the data layer. It looks like the stream-interface's
SI_FL_CAP_SPLICE flag does not make sense anymore as it's used as a proxy
for the pointers above.
It also appears that we call chk_snd() from the recv callback and then
try to call it again in update_conn(). It is very likely that this last
function will progressively slip into the recv/send callbacks in order
to avoid duplicate check code.
The code works right now with and without splicing. Only raw_sock provides
support for it and it is automatically selected when the various splice
options are set. However it looks like splice-auto doesn't enable it, which
possibly means that the streamer detection code does not work anymore, or
that it's only called at a time where it's too late to enable splicing (in
process_session).
Similar to what was done on the receive path, the data layer now provides
only an snd_buf() callback that is iterated over by the stream interface's
si_conn_send_loop() function.
The data layer now has no knowledge about channels nor stream interfaces.
The splice() code still need to be ported as it currently is disabled.
The recv function is now generic and is usable to iterate any connection-to-buf
reading function from a stream interface. So let's move it to stream-interface.
This is the start of the stream connection iterator which calls the
data-layer reader. This still looks a bit tricky but is OK. Splicing
is not handled at all at the moment.
The "raw_sock" prefix will be more convenient for naming functions as
it will be prefixed with the data layer and suffixed with the data
direction. So let's rename the files now to avoid any further confusion.
The #include directive was also removed from a number of files which do
not need it anymore.
At the moment, the struct is still embedded into the struct channel, but
all the functions have been updated to use struct buffer only when possible,
otherwise struct channel. Some functions would likely need to be splitted
between a buffer-layer primitive and a channel-layer function.
Later the buffer should become a pointer in the struct buffer, but doing so
requires a few changes to the buffer allocation calls.
This is a massive rename. We'll then split channel and buffer.
This change needs a lot of cleanups. At many locations, the parameter
or variable is still called "buf" which will become ambiguous. Also,
the "struct channel" is still defined in buffers.h.
This function is used by the data layer when a zero has been read over a
connection. At the moment it only handles sockets and nothing else. Once
the complete split is done between buffers and stream interfaces, it should
become possible to work regardless on the connection type.
The connection send() callback is supposed to be generic for a
stream-interface, and consists in calling the lower layer snd_buf
function. Move this function to the stream interface and remove
the sock-raw and sock-ssl clones.
This callback is used to send data from the buffer to the socket. It is
the old write_loop() call of the data layer which is used both by the
->write() callback and the ->chk_snd() function. The reason for having
it as a pointer is that it's the only remaining part which causes the
write and chk_snd() functions to be different between raw and ssl.
sock_raw and sock_ssl use a pretty generic chk_rcv function, so let's move
this function to the stream_interface and remove specific functions. Later
we might have a single chk_rcv function.
We need to have a generic function to be called by upper layers when buffer
flags have been updated (the si->update function). At the moment, both sock_raw
and sock_ssl had their own which basically was a copy-paste. Since these
functions are only used to update stream interface flags, it is logical to
have them handled by the stream interface code.
This allowed us to remove the stream_interface-specific update function from
sock_raw and sock_ssl which now use the generic code.
The stream_sock_update_conn callback has also been more appropriately renamed
conn_notify_si() since it's meant to be called by lower layers to notify the
SI and possibly upper layers about incoming changes.
This is a second attempt at getting rid of FD_WAIT_*. Now the situation is
much better since native I/O handlers can directly manipulate the FD using
fd_{poll|want|stop}_* and the connection handlers manipulate connection-level
flags using the conn_{data|sock}_* equivalent.
Proceeding this way ensures that the connection flags always reflect the
reality even after data<->handshake switches.
Now the connection handler, the handshake callbacks and the I/O callbacks
make use of the connection-layer polling functions to enable or disable
polling on a file descriptor.
Some changes still need to be done to avoid using the FD_WAIT_* constants.
The conflicts we're facing with polling is that handshake handlers have
precedence over data handlers and may change the polling requirements
regardless of what is expected by the data layer. This causes issues
such as missed events.
The real need is to have three polling levels :
- the "current" one, which is effective at any moment
- the data one, which reflects what the data layer asks for
- the sock one, which reflects what the socket layer asks for
Depending on whether a handshake is in progress or not, either one of the
last two will replace the current one, and the change will be propagated
to the lower layers.
At the moment, the shutdown status is not considered, and only handshakes
are used to decide which layer to chose. This will probably change.
The old EV_FD_SET() macro was confusing, as it would enable receipt but there
was no way to indicate that EAGAIN was received, hence the recently added
FD_WAIT_* flags. They're not enough as we're still facing a conflict between
EV_FD_* and FD_WAIT_*. So let's offer I/O functions what they need to explicitly
request polling.
These functions have a more explicity meaning and will offer provisions
for explicit polling.
EV_FD_ISSET() has been left for now as it is still in use in checks.
Up to now, we had to use a shutr/shutw interface per data layer, which
basically means 3 distinct functions when we include SSL :
- generic stream_interface
- sock_raw
- sock_ssl
With this change, the code located in the stream_interface manages all the
stream_interface and buffer updates, and calls the data layer hooks when
needed.
At the moment, the socket layer hook had been implicitly considered as
being a regular socket, so the si_shut*() functions call the normal
shutdown() and EV_FD_CLR() functions on the fd if a socket layer is
defined. This may change in the future. The stream_int_shut*()
functions don't call EV_FD_CLR() so that they can later be embedded
in lower layers.
Thus, the si->data->shutr() is not called anymore and si->data->shutw()
is called to close the data layer only (eg: only for SSL).
Proceeding like this is very important because it's the only way to be
able not to rely on these functions when called from the connection
handlers, and call the data layers' instead.
These primitives were initially introduced so that callers were able to
conditionally set/disable polling on a file descriptor and check in return
what the state was. It's been long since we last had an "if" on this, and
all pollers' functions were the same for cond_* and their systematic
counter parts, except that this required a check and a specific return
value that are not always necessary.
So let's simplify the FD API by removing this now unused distinction and
by making all specific functions return void.
Handshakes is not called anymore from the data handlers, they're only
called from the connection handler when their flag is set.
Also, this move has uncovered an issue with the stream interface notifier :
it doesn't consider the FD_WAIT_* flags possibly set by the handshake
handlers. This will result in a stuck handshake when no data is in the
output buffer. In order to cover this, for now we'll perform the EV_FD_SET
in the SSL handshake function, but this needs to be addressed separately
from the stream interface operations.
This new flag is used to indicate that the connection was already
connected. It can be used by I/O handlers to know that a connection
has just completed. It is used by stream_sock_update_conn(), allowing
the sock_opt handlers not to manipulate the SI timeout nor the
BF_WRITE_NULL flag anymore.
The sock_ops I/O callbacks made use of an FD till now. This has become
inappropriate and the struct connection is much more useful. It also
fixes the race condition introduced by previous change.
The socket data layer code must only focus on moving data between a
socket and a buffer. We need a special stream interface handler to
update the stream interface and the file descriptor status.
At the moment the code works but suffers from a race condition caused
by its API : the read/write callbacks still make use of the fd instead
of using the connection. And when a double shutdown is performed, a call
to ->write() after ->read() processed an error results in dereferencing
a NULL fdtab[]->owner. This is only a temporary issue which doesn't need
to be fixed now since this will automatically go away when the functions
change to use the connection instead.
Use a single tcp_connect_probe() instead of tcp_connect_write() and
tcp_connect_read(). We call this one only when no data layer function
have been processed, so this is a fallback to test for completion of
a connection attempt.
With this done, we don't have the need for any direct I/O callback
anymore.
The function still relies on ->write() to wake the stream interface up,
so it's not finished.
This handshake handler must be independant, so move it away from
proto_tcp. It has a dedicated connection flag. It is tested before
I/O handlers and automatically removes the CO_FL_WAIT_L4_CONN flag
upon success.
It also sets the BF_WRITE_NULL flag on the stream interface and
stops the SI timeout. However it does not perform the task_wakeup(),
and relies on the data handler to do so for now. The SI wakeup will
have to be moved elsewhere anyway.
fdtab[].state was only used to know whether a connection was in progress
or an error was encountered. Instead we now use connection->flags to store
a flag for both. This way, connection management will be able to update the
connection status on I/O.
In an attempt to get rid of fdtab[].state, and to move the relevant
parts to the connection struct, we remove the FD_STCLOSE state which
can easily be deduced from the <owner> pointer as there is a 1:1 match.
The correct spelling is "independent", not "independant". This patch
fixes the doc and the configuration parser to accept the correct form.
The config parser still allows the old naming for backwards compatibility.
This is used to enter values for stick tables. The most likely usage
is to set gpc0 for a specific IP address in order to block traffic
for abusers without having to reload. Since all data types are
supported, other usages are possible (eg: replace a users's assigned
server).
Source addresses of non-TCP families were not correctly handled by
tcp_src_to_stktable_key() as it forgot to return NULL and instead left
the previous value in the stick-table buffer.
This bug is 1.5-specific and was introduced by commit 4f92d320 in 1.5-dev6
so it does not need any backport.
The destination address is purely a connection thing and not an fd thing.
It's also likely that later the address will be stored into the connection
and linked to by the SI.
struct fdinfo only keeps the pointer to the port range and the local port
for now. All of this also needs to move to the connection but before this
the release of the port range must move from fd_delete() to a new function
dedicated to the connection.
It was not possible to kill remaining sessions from the admin interface,
which is annoying especially when switching to maintenance mode. Now it's
possible.
This implements the feature discussed in the earlier thread of killing
connections on backup servers when a non-backup server comes back up. For
example, you can use this to route to a mysql master & slave and ensure
clients don't stay on the slave after the master goes from down->up. I've done
some minimal testing and it seems to work.
[WT: added session flag & doc, moved the killing after logging the server UP,
and ensured that the new server is really usable]
When passing arguments to ACLs and samples, some types are stored as
strings then resolved later after config parsing is done. Upon exit,
the arguments need to be freed only if the string was not resolved
yet. At the moment we can encounter double free during deinit()
because some arguments (eg: userlists) are freed once as their own
type and once as a string.
The solution consists in adding an "unresolved" flag to the args to
say whether the value is still held in the <str> part or is final.
This could be debugged thanks to a useful bug report from Sander Klein.
httponly This option tells haproxy to add an "HttpOnly" cookie attribute
when a cookie is inserted. This attribute is used so that a
user agent doesn't share the cookie with non-HTTP components.
Please check RFC6265 for more information on this attribute.
secure This option tells haproxy to add a "Secure" cookie attribute when
a cookie is inserted. This attribute is used so that a user agent
never emits this cookie over non-secure channels, which means
that a cookie learned with this flag will be presented only over
SSL/TLS connections. Please check RFC6265 for more information on
this attribute.
This one was already taken care of in proxy_cfg_ensure_no_http(), so if a
cookie is presented in a TCP backend, we got two warnings.
This can be backported to 1.4 since it's been this way for 2 years (although not dramatic).
Cookies were mixed with many other options while they're not used as options.
Move them to a dedicated bitmask (ck_opts). This has released 7 flags in the
proxy options and leaves some room for new proxy flags.
Option httplog needs to be checked only once the proxy has been validated,
so that its final mode (tcp/http) can be used. Also we need to check for
httplog before checking the log format, so that we can report a warning
about this specific option and not about the format it implies.
Commit 13e66da introduced b_rew() but passes -adv which is an unsigned
quantity on 64-bit platforms, causing the buffer to advance in the wrong
direction.
No backport is needed.
This patch brings a new "whole" parameter to "balance uri" which makes
the hash work over the whole uri, not just the part before the query
string. Len and depth parameter are still honnored.
The reason for this new feature is explained below.
I have 3 backend servers, each accepting different form of HTTP queries:
http://backend1.server.tld/service1.php?q=...
http://backend1.server.tld/service2.php?q=...
http://backend2.server.tld/index.php?query=...&subquery=...
http://backend3.server.tld/image/49b8c0d9ff
Each backend server returns a different response based on either:
- the URI path (the left part of the URI before the question mark)
- the query string (the right part of the URI after the question mark)
- or the combination of both
I wanted to set up a common caching cluster (using 6 Squid servers, each
configured as reverse proxy for those 3 backends) and have HAProxy balance
the queries among the Squid servers based on URL. I also wanted to achieve
hight cache hit ration on each Squid server and send the same queries to
the same Squid servers. Initially I was considering using the 'balance uri'
algorithm, but that would not work as in case of backend2 all queries would
go to only one Squid server. The 'balance url_param' would not work either
as it would send the backend3 queries to only one Squid server.
So I thought the simplest solution would be to use 'balance uri', but to
calculate the hash based on the whole URI (URI path + query string),
instead of just the URI path.
The listener struct is now aware of the socket layer to use upon accept().
At the moment, only sock_raw is supported so this patch should not change
anything.
When the target is a client, it will be convenient to have a pointer to the
original listener so that we can retrieve some configuration information at
the stream interface level.
This function will be called later when splitting the shutdown in two
steps. It will be needed by SSL and for remote socket operations to
release unused contexts.
The state and the private pointer are not specific to the applets, since SSL
will require exactly both of them. Move them to the connection layer now and
rename them. We also now ensure that both are NULL on first call.
We start to move everything needed to manage a connection to a special
entity "struct connection". We have the data layer operations and the
control operations there. We'll also have more info in the future such
as file descriptors and applet contexts, so that in the end it becomes
detachable from the stream interface, which will allow connections to
be reused between sessions.
For now on, we start with minimal changes.
David Touzeau reported that haproxy dies when a server is checked and is
used in a farm with only "option transparent" and no LB algo. This is
because the LB params are NULL, the functions should be checked before
being called.
The same bug is present in 1.4 so this patch must be backported.
msg->som was zero before the body and was used to carry the beginning
of a chunk size for chunked-encoded messages, at a moment when msg->sol
is always zero.
Remove msg->som and replace it with msg->sol where needed.
This is a left-over from the buffer changes. Msg->sol is always null at the
end of the parsing, so we must not use it anymore to read headers or find
the beginning of a message. As a side effect, the dump of the request in
debug mode is working again because it was relying on msg->sol not being
null.
Maybe it will even be mergeable with another of the message pointers.
Calling the init() function in sess_establish was a bad idea, it is
too late to allow it to fail on lack of resource and does not help at
all. Remove it for now before it's used.
Before it was possible to resize the buffers using global.tune.bufsize,
the trash has always been the size of a buffer by design. Unfortunately,
the recent buffer sizing at runtime forgot to adjust the trash, resulting
in it being too short for content rewriting if buffers were enlarged from
the default value.
The bug was encountered in 1.4 so the fix must be backported there.
This flag indicates that we're not interested in keeping half-open
connections on a stream interface. It has the benefit of allowing
the socket layer to cause an immediate write close when detecting
an incoming read close. This releases resources much faster and
saves one syscall (either a shutdown or setsockopt).
This flag is only set by HTTP on the interface going to the server
since we don't want to continue pushing data there when it has
closed.
Another benefit is that it responds with a FIN to a server's FIN
instead of responding with an RST as it used to, which is much
cleaner.
Performance gains of 7.5% have been measured on HTTP connection
rate on empty objects.
These pointers were used to hold pointers to buffers in the past, but
since we introduced the stream interface, they're no longer used but
they were still sometimes set.
Removing them shrink the struct fdtab from 32 to 24 bytes on 32-bit machines,
and from 52 to 36 bytes on 64-bit machines, which is a significant saving. A
quick tests shows a steady 0.5% performance gain, probably due to the better
cache efficiency.
This macro is usable like printf but sends messages to fd #-1, which has no
visible effect but is easy to spot in strace. This is very useful to put
tracers at many points during debugging sessions.
Tunnel timeouts are used when TCP connections are forwarded, or
when forwarding upgraded HTTP connections (WebSocket) as well as
CONNECT requests to proxies.
This timeout allows long-lived sessions to be supported without
having to set large timeouts to normal requests.
Instead of hard-coding sock_raw in connect_server(), we set this socket
operation at config parsing time. Right now, only servers and peers have
it. Proxies are still hard-coded as sock_raw. This will be needed for
future work on SSL which requires a different socket layer.
Similarly to the previous patch, we don't need the socket-layer functions
outside of stream_interface. They could even move to a file dedicated to
applets, though that does not seem particularly useful at the moment.
Commit e164e7a removed get_src/get_dst setting in the stream interfaces but
forgot to set it in proto_tcp. Get the feature back because we need it for
logging, transparent mode, ACLs etc... We now rely on the stream interface
direction to know what syscall to use.
One benefit of doing it this way is that we don't use getsockopt() anymore
on outgoing stream interfaces nor on UNIX sockets.
We'll soon have an SSL socket layer, and in order to ease the difference
between the two, we use the name "sock_raw" to designate the one which
directly talks to the sockets without any conversion.
There is no more reason for the realign function being HTTP specific,
it only operates on a buffer now. Let's move it to buffers.c instead.
It's likely that buffer_bounce_realign is broken (not used), this will
have to be inspected. The function is worth rewriting as it can be
cheaper than buffer_slow_realign() to realign large wrapping buffers.
All keywords registered using a cfg_kw_list now make use of the new error reporting
framework. This allows easier and more precise error reporting without having to
deal with complex buffer allocation issues.
From time to time, some bugs are discovered that are caused by non-initialized
memory areas. It happens that most platforms return a zero-filled area upon
first malloc() thus hiding potential bugs. This patch also replaces malloc()
in pools with calloc() to ensure that all platforms exhibit the same behaviour
upon startup. In order to catch these bugs more easily, add a -dM command line
flag to enable memory poisonning. Optionally, passing -dM<byte> forces the
poisonning byte to <byte>.
A number of important information were missing from the error captures, so
let's improve them. Now we also log source port, session flags, transaction
flags, message flags, pending output bytes, expected buffer wrapping position,
total bytes transferred, message chunk length, and message body length.
As such, the output format has slightly evolved and the source address moved
to the third line :
[08/May/2012:11:14:36.341] frontend echo (#1): invalid request
backend echo (#1), server <NONE> (#-1), event #1
src 127.0.0.1:40616, session #4, session flags 0x00000000
HTTP msg state 26, msg flags 0x00000000, tx flags 0x00000000
HTTP chunk len 0 bytes, HTTP body len 0 bytes
buffer flags 0x00909002, out 0 bytes, total 28 bytes
pending 28 bytes, wrapping at 8030, error at position 7:
00000 GET / /?t=20000 HTTP/1.1\r\n
00026 \r\n
[08/May/2012:11:13:13.426] backend echo (#1) : invalid response
frontend echo (#1), server local (#1), event #0
src 127.0.0.1:40615, session #1, session flags 0x0000044e
HTTP msg state 32, msg flags 0x0000000e, tx flags 0x08200000
HTTP chunk len 0 bytes, HTTP body len 20 bytes
buffer flags 0x00008002, out 81 bytes, total 92 bytes
pending 11 bytes, wrapping at 7949, error at position 9:
00000 Foo: bar\r\r\n
The previous sockstream_accept() function uses nothing from sockstream, and
is totally irrelevant to stream interfaces. Move this to the protocols.c
file which handles listeners and protocols, and call it listener_accept().
It now makes much more sense that the code dealing with listen() also handles
accept() and passes it to upper layers.
These operators are used regardless of the socket protocol family. Move
them to a "sock_ops" struct. ->read and ->write have been moved there too
as they have no reason to remain at the protocol level.
Make use of the new IPv6 pattern type so that acl_match_ip() knows how to
compare pattern and sample.
IPv6 may be entered in their usual form, with or without a netmask appended.
Only bit counts are accepted for IPv6 netmasks. In order to avoid any risk of
trouble with randomly resolved IP addresses, host names are never allowed in
IPv6 patterns.
HAProxy is also able to match IPv4 addresses with IPv6 addresses in the
following situations :
- tested address is IPv4, pattern address is IPv4, the match applies
in IPv4 using the supplied mask if any.
- tested address is IPv6, pattern address is IPv6, the match applies
in IPv6 using the supplied mask if any.
- tested address is IPv6, pattern address is IPv4, the match applies in IPv4
using the pattern's mask if the IPv6 address matches with 2002:IPV4::,
::IPV4 or ::ffff:IPV4, otherwise it fails.
- tested address is IPv4, pattern address is IPv6, the IPv4 address is first
converted to IPv6 by prefixing ::ffff: in front of it, then the match is
applied in IPv6 using the supplied IPv6 mask.
We cannot currently match IPv6 addresses in ACL simply because we don't
support types on the patterns. Let's introduce this notion. For now, we
rely on the SMP_TYPES though it doesn't seem like it will last forever
given that some types are not present there (eg: regex, meth). Still it
should be enough to support mixed matchings for most types.
We use the special impossible value SMP_TYPES for types that don't exist
in the SMP_T_* space.
This is mainly a massive renaming in the code to get it in line with the
calling convention. Next patch will rename a few files to complete this
operation.
All parsing errors were known but impossible to return. Now by making use
of memprintf(), we're able to build meaningful error messages that the
caller can display.
HTTP header fetch is now done using smp_fetch_hdr() for both ACLs and
patterns. This one also supports an occurrence number, making it possible
to specify explicit occurrences for ACLs and patterns.
This way, fetch functions will be able to tell if they're called for a single
request or as part of a loop. This is important for instance when we use
hdr(foo), because in an ACL this means that all hdr(foo) occurrences must
be checked while in a pattern it means only one of them (eg: last one).
Patterns were using a bitmask to indicate if request or response was desired
in fetch functions and keywords. ACLs were using a bitmask in fetch keywords
and a single bit in fetch functions. ACLs were also using an ACL_PARTIAL bit
in fetch functions indicating that a non-final fetch was performed, which was
an abuse of the existing direction flag.
The change now consists in using :
- a capabilities field for fetch keywords => SMP_CAP_REQ/RES to indicate
if a keyword supports requests, responses, both, etc...
- an option field for fetch functions to indicate what the caller expects
(request/response, final/non-final)
The ACL_PARTIAL bit was reversed to get SMP_OPT_FINAL as it's more explicit
to know we're working on a final buffer than on a non-final one.
ACL_DIR_* were removed, as well as PATTERN_FETCH_*. L4 fetches were improved
to support being called on responses too since they're still available.
The <dir> field of all fetch functions was changed to <opt> which is now
unsigned.
The patch is large but mostly made of cosmetic changes to accomodate this, as
almost no logic change happened.
Having the args everywhere will make it easier to share fetch functions
between patterns and ACLs. The only place where we could have needed
the expr was in the http_prefetch function which can do well without.
Previously, both pattern, backend and persist_rdp_cookie would build fake
ACL expressions to fetch an RDP cookie by calling acl_fetch_rdp_cookie().
Now we switch roles. The RDP cookie fetch function is provided as a sample
fetch function that all others rely on, including ACL. The code is exactly
the same, only the args handling moved from expr->args to args. The code
was moved to proto_tcp.c, but probably that a dedicated file would be more
suited to content handling.
Now there is no more reference to union pattern_data. All pattern fetch and
conversion functions now make use of the common sample type. Note: none of
them adjust the type right now so it's important to do it next otherwise
we would risk sharing such functions with ACLs and seeing them fail.
This change is pretty minor. Struct pattern is only used for
pattern_process() now so changing it to use the common type is
quite obvious. It's worth noting that the last argument of
pattern_process() is never used so the function is self-sufficient.
Note that pattern_process() does not initialize the pattern at all
before calling fetch->process(), and that minimal initialization
will be required when we later change the argument for the sample.
These ones were either unused or improperly used. Some integers were marked
read-only, which does not make much sense. Buffers are not read-only, they're
"constant" in that they must be kept intact after any possible change.
This one is not needed anymore as we can return the data and its type in the
sample provided by the caller. ACLs now always return the proper type. BOOL
is already returned when the result is expected to be processed as a boolean.
temp_pattern has been unexported now.
The new sample types are necessary for the acl-pattern convergence.
These types are boolean and signed int. Some types were renamed for
less ambiguity (ip->ipv4, integer->uint).
The pattern type is ambiguous because a pattern is only a type and a data
part, and is normally used to match against samples. Currently, patterns
cannot hold information related to the life of the data which was extracted.
We don't want to overload patterns either, so let's add a new "sample" type
which will progressively supersede the acl_test and maybe the pattern at most
places. The sample shares similar information with patterns and also has flags
describing the data volatility and protection.
This flag was used to force a boolean match even if there was no pattern
to match. It was used only by http_auth() and designed only for this one.
It's easier and cleaner to make the fetch function perform the test and
report the boolean result as a few other functions already do. It simplifies
the acl_exec_cond() logic and will help merging ACLs and patterns.
This is used to validate that arguments are coherent. For instance,
payload_lv expects that the last arg (if any) is not more negative
than the sum of the first two. The error is reported if any.
We don't need the pattern-specific args parsers anymore, make use of the
common parser instead. We still need to improve this by adding a validation
function to report abnormal argument values or combinations. We don't report
precise parsing errors yet but this was not previously done either.
arg_i was almost unused, and since we migrated to use struct arg everywhere,
the rare cases where arg_i was needed could be replaced by switching to
arg->type = ARGT_STOP.
The types and minimal number of ACL keyword arguments are now stored in
their declaration. This will allow many more fantasies if some ACL use
several arguments or types.
Doing so required to rework all ACL keyword declarations to add two
parameters. So this was a good opportunity for a general cleanup and
to sort all entries in alphabetical order.
We still have two pending issues :
- parse_acl_expr() checks for errors but has no way to report them to
the user ;
- the types of some arguments are still not resolved and kept as strings
(eg: ARGT_FE/BE/TAB) for compatibility reasons, which must be resolved
in acl_find_targets()
The ACL parser now uses the argument parser to build a typed argument list.
Right now arguments are all strings and only one argument is supported since
this is what ACLs currently support.
make_arg_list() builds an array of typed arguments with their values,
that the caller describes how to parse. This will be used to support
multiple arguments for ACLs and patterns, which is currently problematic
and prevents ACLs and patterns from being merged. Up to 7 arguments types
may be enumerated in a single 32-bit word, including their number of
mandatory parts.
At the moment, these files are not used yet, they're only built. Note that
the 4-bit encoding for the type has left only one unused type!
This is more convenient and efficient than buf->p = b_ptr(buf, n);
It simply advances the buffer's pointer by <n> and trasfers that
amount of bytes from <in> to <out>. The BF_OUT_EMPTY flag is updated
accordingly.
A few occurrences of such computations in buffers.c and stream_sock.c
were updated to use b_adv(), which resulted in a small code shrink.
buffer_wrap_add was convenient for the migration but is not handy at all.
Let's have new wrappers that report input begin/end and output begin/end
instead.
It looks like we'll also need a b_adv(ofs) to advance a buffer's pointer.
buffer_ignore may only be used when the output of a buffer is empty,
but it's not granted it is always the case when sending HTTP error
responses. Better use buffer_cut_tail() instead, and use buffer_ignore
only on non-wrapping data.
msg->sol is now a relative pointer just like all other ones. There is no
more absolute references to the buffer outside the struct buffer itself.
Next two cleanups should include removing buffer references to functions
which already have an msg, and removal of wrapping detection in request
and response parsing which cannot wrap by definition.
ACLs and patterns only rely on a struct http_msg and don't know the pointer
to the actual data. struct http_msg will soon only hold relative references
so that's not possible. We need http_msg to hold a reference to the struct
buffer before having relative pointers everywhere.
It is likely that doing so will also result in opportunities to simplify
a number of functions arguments. The following functions are already
candidate :
http_buffer_heavy_realign
http_capture_bad_message
http_change_connection_header
http_forward_trailers
http_header_add_tail
http_header_add_tail2
http_msg_analyzer
http_parse_chunk_size
http_parse_connection_header
http_remove_header2
http_send_name_header
http_skip_chunk_crlf
http_upgrade_v09_to_v10
These offsets were relative to the buffer itself. Now they're relative to
the buffer's origin (buf->p) which normally corresponds to the start of
current message.
This saves a big dependency between the HTTP message struct and the buffers.
It appeared during this change that ->col is not used anymore (it will have
to be removed). Next step is to turn ->eol and ->sol from absolute to relative.
The buffer's pointer <lr> was only used by HTTP parsers which also use a
struct http_msg to keep track of the parser's state. We've reached a point
where it makes no sense to keep ->lr in the buffer, as the split between
buffer and msg is only arbitrary for historical reasons.
This change ensures that touching buffers will not impact HTTP messages
anymore, making the buffers more content-agnostic. However, it becomes
very important not to forget to update msg->next when some data get
forwarded or moved (and in general each time buf->p is updated).
The new pointer in http_msg becomes relative to buffer->p so that
parsing multiple messages becomes easier. It is possible that at one
point ->som and ->next will be merged.
Note: http_parse_reqline() and http_parse_stsline() have been temporarily
modified to know the message starting point in the buffer (->p).
This change gets rid of buf->r which is always equal to buf->p + buf->i.
It removed some wrapping detection at a number of places, but required addition
of new relative offset computations at other locations. A large number of places
can be simplified now with extreme care, since most of the time, either the
pointer has to be computed once or we need a difference between the old ->w and
old ->r to compute free space. The cleanup will probably happen with the rewrite
of the buffer_input_* and buffer_output_* functions anyway.
buf->lr still has to move to the struct http_msg and be relative to buf->p
for the rework to be complete.
This change introduces the buffer's base pointer, which is the limit between
incoming and outgoing data. It's the point where the parsing should start
from. A number of computations have already been greatly simplified, but
more simplifications are expected to come from the removal of buf->r.
The changes appear good and have revealed occasional improper use of some
pointers. It is possible that this patch has introduced bugs or revealed
some, although preliminary testings tend to indicate that everything still
works as it should.
We don't have buf->l anymore. We have buf->i for pending data and
the total length is retrieved by adding buf->o. Some computation
already become simpler.
Despite extreme care, bugs are not excluded.
It's worth noting that msg->err_pos as set by HTTP request/response
analysers becomes relative to pending data and not to the beginning
of the buffer. This has not been completed yet so differences might
occur when outgoing data are left in the buffer.
Too many flags are stored in the transaction structure. Some flags are
clearly message-specific and exist in two versions (request and response).
Move them to a new "flags" field in the http_message struct instead.
memprintf() is just like snprintf() except that it always returns a properly
sized allocated string that the caller is responsible for freeing. NULL is
returned on serious errors. It also supports stackable calls over the same
pointer since it offers support for automatically freeing a previous one :
memprintf(&err, "invalid argument: '%s'", arg);
...
memprintf(&err, "keyword parser said: <%s>", *err);
...
memprintf(&err, "line parser said: %s\n", *err);
...
free(*err);
It's very annoying that we have to deal with the crappy size_t and with ints
at some places because these ones don't mix well. Patch 6f61b2 changed the
chunk len to int but its size remains size_t and some functions are having
trouble being used by several callers depending on the type of their arguments.
Let's turn extract_cookie_value() to int for now on, and plan a massive cleanup
later to remove all size_t.
These callbacks are used to retrieve the source and destination address
of a socket. The address flags are not hold on the stream interface and
not on the session anymore. The addresses are collected when needed.
This still needs to be improved to store the IP and port separately so
that it is not needed to perform a getsockname() when only the IP address
is desired for outgoing traffic.
The Unique ID, is an ID generated with several informations. You can use
a log-format string to customize it, with the "unique-id-format" keyword,
and insert it in the request header, with the "unique-id-header" keyword.
%Fi: Frontend IP
%Fp: Frontend Port
%Si: Server IP
%Sp: Server Port
%Ts: Timestamp
%rt: HTTP request counter
%H: hostname
%pid: PID
+X: Hexadecimal represenation
The +X mode in logformat displays hexadecimal for the following flags
%Ci %Cp %Fi %Fp %Bi %Bp %Si %Sp %Ts %ct %pid
rename logformat_write_string() to lf_text()
Optimize size computation
* logformat functions now take a format linked list as argument
* build_logline() build a logline using a format linked list
* rename LOG_* by LOG_FMT_* in enum
* improve error management in build_logline()
Sometimes it is desirable to forward a particular request to a specific
server without having to declare a dedicated backend for this server. This
can be achieved using the "use-server" rules. These rules are evaluated after
the "redirect" rules and before evaluating cookies, and they have precedence
on them. There may be as many "use-server" rules as desired. All of these
rules are evaluated in their declaration order, and the first one which
matches will assign the server.
memcmp()/strcmp() calls were needed in different parts of code to determine
the status code. Each new status code introduces new calls, which can become
inefficient and source of bugs.
This patch reorganizes the code to rely on a numeric status code internally
and to be hopefully more generic.
Previously, the stats admin page required POST parameters to be provided
exactly in the same order as the HTML form.
This patch allows to handle those parameters in any orders.
Also, note that haproxy won't alter server states anymore if backend or server
names are ambiguous (duplicated names in the configuration) to prevent
unexpected results (the same should probably be applied to the stats socket).
Commit a1cc38 introduced a regression which was easy to trigger till ad4cd58
(snapshots 20120222 to 20120311 included). The bug was still present after
that but harder to trigger.
The bug is caused by the use of two distinct log buffers due to intermediary
changes. The issue happens when an HTTP request is logged just after a TCP
request during the same second and the HTTP request is too large for the buffer.
In this case, it happens that the HTTP request is logged into the TCP buffer
instead and that length controls can't detect anything.
Starting with bddd4f, the issue is still possible when logging too large an
HTTP request just after a send_log() call (typically a server status change).
We owe a big thanks to Sander Klein for testing several snapshots and more
specifically for taking significant risks in production by letting the buggy
version crash several times in order to provide an exploitable core ! The bug
could not have been found without this precious help. Thank you Sander !
This fix does not need to be backported, it did not affect any released version.
The difference could be seen when logging a request in HTTP mode with option
tcplog, as it would keep emitting 4 chars. Better use two distinct flags to
clear the confusion.
%Bi return the backend source IP
%Bp return the backend source port
Add a function pointer in logformat_type to do additional configuration
during the log-format variable parsing.
Merge http_sess_log() and tcp_sess_log() to sess_log() and move it to
log.c
A new field in logformat_type define if you can use a logformat
variable in TCP or HTTP mode.
doc: log-format in tcp mode
Note that due to the way log buffer allocation currently works, trying to
log an HTTP request without "option httplog" is still not possible. This
will change in the near future.
A number of offset computation functions use struct buffer* arguments
and return integers without modifying the input. Using consts helps
simplifying some operations in callers.
The principle behind this load balancing algorithm was first imagined
and modeled by Steen Larsen then iteratively refined through several
work sessions until it would totally address its original goal.
The purpose of this algorithm is to always use the smallest number of
servers so that extra servers can be powered off during non-intensive
hours. Additional tools may be used to do that work, possibly by
locally monitoring the servers' activity.
The first server with available connection slots receives the connection.
The servers are choosen from the lowest numeric identifier to the highest
(see server parameter "id"), which defaults to the server's position in
the farm. Once a server reaches its maxconn value, the next server is used.
It does not make sense to use this algorithm without setting maxconn. Note
that it can however make sense to use minconn so that servers are not used
at full load before starting new servers, and so that introduction of new
servers requires a progressively increasing load (the number of servers
would more or less follow the square root of the load until maxconn is
reached). This algorithm ignores the server weight, and is more beneficial
to long sessions such as RDP or IMAP than HTTP, though it can be useful
there too.
http_sess_log now use the logformat linked list to make the log
string, snprintf is not used for speed issue.
CLF mode also uses logformat.
NOTE: as of now, empty fields in CLF now are "" not "-" anymore.
parse_logformat_string: parse the string, detect the type: text,
separator or variable
parse_logformat_var: dectect variable name
parse_logformat_var_args: parse arguments and flags
add_to_logformat_list: add to the logformat linked list
send_log function is now splited in 3 functions
* hdr_log: generate the syslog header
* send_log: send a syslog message with a printf format string
* __send_log: send a syslog message
It was reported that a server configured with a zero weight would
sometimes still take connections from the backend queue. This issue is
real, it happens this way :
1) the disabled server accepts a request with a cookie
2) many cookie-less requests accumulate in the backend queue
3) when the disabled server completes its request, it checks its own
queue and the backend's queue
4) the server takes a pending request from the backend queue and
processes it. In response, the server's cookie is assigned to
the client, which ensures that some requests will continue to
be served by this server, leading back to point 1 above.
The fix consists in preventing a zero-weight server from dequeuing pending
requests from the backend. Making use of srv_is_usable() in such tests makes
the tests more robust against future changes.
This fix must be backported to 1.4 and 1.3.
In a config where server "s1" is marked disabled and "s2" tracks "s1",
s2 appears disabled on the stats but is still inserted into the LB farm
because the tracking is resolved too late in the configuration process.
We now resolve tracked servers before building LB maps and we also mark
the tracking server in maintenance mode, which previously was not done,
causing half of the issue.
Last point is that we also protect srv_is_usable() against electing a
server marked for maintenance. This is not absolutely needed but is a
safe choice and makes a lot of sense.
This fix must be backported to 1.4.
New option "http-send-name-header" specifies the name of a header which
will hold the server name in outgoing requests. This is the name of the
server the connection is really sent to, which means that upon redispatches,
the header's value is updated so that it always matches the server's name.
The new function does not return IP addresses but header values instead,
so that the caller is free to make what it want of them. The conversion
is not quite clean yet, as the previous test which considered that address
0.0.0.0 meant "no address" is still used. A different IP parsing function
should be used to take this into account.
Till now the pattern data integer type was unsigned without any
particular reason. In order to make ACLs use it, we must switch it
to signed int instead.
(from ebtree 6.0.6)
This version is mainly aimed at clarifying the fact that the ebtree license
is LGPL. Some files used to indicate LGPL and other ones GPL, while the goal
clearly is to have it LGPL. A LICENSE file has also been added.
No code is affected, but it's better to have the local tree in sync anyway.
(cherry picked from commit 24dc7cca051f081600fe8232f33e55ed30e88425)
In commit 4b517ca93a (MEDIUM: buffers:
add some new primitives and rework existing ones), we forgot to check
if buffer_max_len() < l.
No backport is needed.
A number of primitives were missing for buffer management, and some
of them were particularly awkward to use. Specifically, the functions
used to compute free space could not always be used depending what was
wrapping in the buffers. Some documentation has been added about how
the buffers work and their properties. Some functions are still missing
such as a buffer replacement which would support wrapping buffers.
This patch settles the 2 loggers limitation.
Loggers are now stored in linked lists.
Using "global log", the global loggers list content is added at the end
of the current proxy list. Each "log" entries are added at the end of
the proxy list.
"no log" flush a logger list.
Ludovic Levesque reported and diagnosed an annoying bug. When a server is
configured to track another one and has a slowstart interval set, it's
assigned a minimal weight when the tracked server goes back up but keeps
this weight forever.
This is because the throttling during the warmup phase is only computed
in the health checking function.
After several attempts to resolve the issue, the only real solution is to
split the check processing task in two tasks, one for the checks and one
for the warmup. Each server with a slowstart setting has a warmum task
which is responsible for updating the server's weight after a down to up
transition. The task does not run in othe situations.
In the end, the fix is neither complex nor long and should be backported
to 1.4 since the issue was detected there first.
When reading the code, the "tracked" member of a server makes one
think the server is tracked while it's the opposite, it's a pointer
to the server being tracked. This is particularly true in constructs
such as :
if (srv->tracked) {
Since it's the second time I get caught misunderstanding it, let's
rename it to "track" to avoid the confusion.
For a long time, the max number of headers was taken as a part of the buffer
size. Since the header size can be configured at runtime, it does not make
much sense anymore.
Nothing was making it necessary to have a static value, so let's turn this into
a tunable with a default value of 101 which equals what was previously used.
It makes no sense to have one pointer to the hdr_idx pool in each proxy
struct since these pools do not depend on the proxy. Let's have a common
pool instead as it is already the case for other types.
By default, pipes are the default size for the system. But sometimes when
using TCP splicing, it can improve performance to increase pipe sizes,
especially if it is suspected that pipes are not filled and that many
calls to splice() are performed. This has an impact on the kernel's
memory footprint, so this must not be changed if impacts are not understood.
Struct sockaddr_storage is huge (128 bytes) and severely impacts the
cache. It also displaces other struct members, causing them to have
larger relative offsets. By moving these few occurrences to the end
of the structs which host them, we can reduce the code size by no less
than 2 kB !
Stream interfaces used to distinguish between client and server addresses
because they were previously of different types (sockaddr_storage for the
client, sockaddr_in for the server). This is not the case anymore, and this
distinction is confusing at best and has caused a number of regressions to
be introduced in the process of converting everything to full-ipv6. We can
now remove this and have a much cleaner code.
This patch introduces hdr_len, path_len and url_len for matching these
respective parts lengths against integers. This can be used to detect
abuse or empty headers.
These requests are mainly monitor requests, as well as stats requests when
the stats are processed by the frontend. Having this counter helps explain
the difference in number of sessions that is sometimes observed between a
frontend and a backend.
We now measure the work and idle times in order to report the idle
time in the stats. It's expected that we'll be able to use it at
other places later.
We already had the ability to kill a connection, but it was only
for the checks. Now we can do this for any session, and for this we
add a specific flag "K" to the logs.
The stats socket now allows the admin to disable, enable or shutdown a frontend.
This can be used when a bug is discovered in a configuration and it's desirable
to fix it but the rules in place don't allow to change a running config. Thus it
becomes possible to kill the frontend to release the port and start a new one in
a separate process.
This can also be used to temporarily make haproxy return TCP resets to incoming
requests to pretend the service is not bound. For instance, this may be useful
to quickly flush a very deep SYN backlog.
The frontend check and lookup code was factored with the "set maxconn" usage.
This one enforces a per-process connection rate limit, regardless of what
may be set per frontend. It can be a way to limit the CPU usage of a process
being severely attacked.
The side effect is that the global process connection rate is now measured
for each incoming connection, so it will be possible to report it.
This option permits to change the global maxconn setting within the
limit that was set by the initial value, which is now reported as the
hard maxconn value. This allows to immediately accept more concurrent
connections or to stop accepting new ones until the value passes below
the indicated setting.
The main use of this option is on systems where many haproxy instances
are loaded and admins need to re-adjust resource sharing at run time
to regain a bit of fairness between processes.
Trailing spaces after headers were not trimmed, only the leading ones
were. An issue was detected today with a content-length value which
was padded with spaces and which was rejected. Recent updates to the
http-bis draft made it a lot more clear that such spaces must be ignored,
so this is what this patch does.
It should be backported to 1.4.
Many inet_ntop calls were partially right, which was hard to detect given
the complex combinations. Some of them were relying on the listener's proto
instead of the address itself, which could have been different when dealing
with an accept-proxy connection.
The new addr_to_str() function does the dirty job and returns the family, which
makes it particularly suited to calls from switch/case statements. A large number
of if/else statements were removed and the stats output could even be cleaned up
in the case of session dump.
As a side effect of doing this, the resulting code is smaller by almost 1kB.
All changed parts have been tested and provided expected output.
Some older libc don't define splice() and and don't define _syscall*()
either, which causes build errors if splicing is enabled.
To solve this, we now split the syscall redefinition into two layers :
- one file per syscall (epoll, splice)
- one common file to declare the _syscall*() macros
The code is cleaner because files using the syscalls just have to include
their respective file. It's not adviced to merge multiple syscall families
into a same file if all are not intended to be used simultaneously, because
defining unused static functions causes warnings to be emitted during build.
As a result, the new USE_MY_SPLICE parameter was added in order to be able
to define the splice() syscall separately.
If "option forwardfor" has the "if-none" argument, then the header is
only added when the request did not already have one. This option has
security implications, and should not be set blindly.
Manoj Kumar reported a case where haproxy would crash upon start-up. The
cause was an "http-check expect" statement declared in the defaults section,
which caused a NULL regex to be used during the check. This statement is not
allowed in defaults sections precisely because this requires saving a copy
of the regex in the default proxy. But the check was not made to prevent it
from being declared there, hence the issue.
Instead of adding code to detect its abnormal use, we decided to implement
it. It was not that much complex because the expect_str part was not used
with regexes, so it could hold the string form of the regex in order to
compile it again for every backend (there's no way to clone regexes).
This patch has been tested and works. So it's both a bugfix and a minor
feature enhancement.
It should be backported to 1.4 though it's not critical since the config
was not supposed to be supported.
Adding health checks has become a real pain, with cross-references to all
checks everywhere because they're all a single bit. Since they're all
exclusive, let's change this to have a check number only. We reserve 4
bits allowing up to 16 checks (15+tcp), only 7 of which are currently
used. The code has shrunk by almost 1kB and we saved a few option bits.
The "dispatch" option has been moved to px->options, making a few tests
a bit cleaner.
This patch provides a new "option redis-check" statement to enable server health checks based on redis PING request (http://www.redis.io/commands/ping).
This global task is used to periodically check for end of resource shortage
and to try to enable queued listeners again. This is important in case some
temporary system-wide shortage is encountered, so that we don't have to wait
for an existing connection to be released before checking the queue again.
For situations where listeners are queued due to the global maxconn being
reached, the task is woken up at least every second. For situations where
a system resource shortage is detected (memory, sockets, ...) the task is
woken up at least every 100 ms. That way, recovery from severe events can
still be achieved under acceptable conditions.
This was revealed with one of the very latest patches which caused
the listener_queue not to be initialized on the stats socket frontend.
And in fact a number of other ones were missing too. This is getting so
boring that now we'll always make use of the same function to initialize
any proxy. Doing so has even saved about 500 bytes on the binary due to
the avoided code redundancy.
No backport is needed.
This function is finally not needed anymore, as it has been replaced with
a per-proxy task that is scheduled when some limits are encountered on
incoming connections or when the process is stopping. The savings should
be noticeable on configs with a large number of proxies. The most important
point is that the rate limiting is now enforced in a clean and solid way.
Those states have been replaced with PR_STFULL and PR_STREADY respectively,
as it is what matches them the best now. Also, two occurrences of PR_STIDLE
in peers.c have been removed as this did not provide any form of error recovery
anyway.
All listeners that are limited by a proxy-specific resource are now
queued at the proxy's and not globally. This allows finer-grained
wakeups when releasing resource.
When an accept() fails because of a connection limit or a memory shortage,
we now disable it and queue it so that it's dequeued only when a connection
is released. This has improved the behaviour of the process near the fd limit
as now a listener with a no connection (eg: stats) will not loop forever
trying to get its connection accepted.
The solution is still not 100% perfect, as we'd like to have this used when
proxy limits are reached (use a per-proxy list) and for safety, we'd need
to have dedicated tasks to periodically re-enable them (eg: to overcome
temporary system-wide resource limitations when no connection is released).
When a listeners encounters a resource shortage, it currently stops until
one re-enables it. This is far from being perfect as it does not yet handle
the case where the single connection from the listener is rejected (eg: the
stats page).
Now we'll have a special status for resource limited listeners and we'll
queue them into one or multiple lists. That way, each time we have to stop
a listener because of a resource shortage, we can enqueue it and change its
state, so that it is dequeued once more resources are available.
This patch currently does not change any existing behaviour, it only adds
the basic building blocks for doing that.
Managing listeners state is difficult because they have their own state
and can at the same time have theirs dictated by their proxy. The pause
is not done properly, as the proxy code is fiddling with sockets. By
introducing new functions such as pause_listener()/resume_listener(), we
make it a bit more obvious how/when they're supposed to be used. The
listen_proxies() function was also renamed to resume_proxies() since
it's only used for pause/resume.
This patch is the first in a series aiming at getting rid of the maintain_proxies
mess. In the end, proxies should not call enable_listener()/disable_listener()
anymore.
Patch af5149 introduced an issue which can be detected only on out of
memory conditions : a LIST_DEL() may be performed on an uninitialized
struct member instead of a LIST_INIT() during the accept() phase,
causing crashes and memory corruption to occur.
This issue was detected and diagnosed by the Exceliance R&D team.
This is 1.5-specific and very recent, so no existing deployment should
be impacted.
Never add connections allocated to this sever to a stick-table.
This may be used in conjunction with backup to ensure that
stick-table persistence is disabled for backup servers.
apsession_refresh() and apsess_refressh are only used inside apsession.c
and thus can be made static.
The only use of apsession_refresh() is appsession_task_init().
These functions have been re-ordered to avoid the need for
a forward-declaration of apsession_refresh().
If a connection is closed by because the backend became unavailable
then log 'D' as the termination condition.
Signed-off-by: Simon Horman <horms@verge.net.au>
This adds the "on-marked-down shutdown-sessions" statement on "server" lines,
which causes all sessions established on a server to be killed at once when
the server goes down. The task's priority is reniced to the highest value
(1024) so that servers holding many tasks don't cause a massive slowdown due
to the wakeup storm.
The motivation for this is to allow iteration of all the connections
of a server without the expense of iterating over the global list
of connections.
The first use of this will be to implement an option to close connections
associated with a server when is is marked as being down or in maintenance
mode.
* The declaration of peer_session_create() does
not match its definition. As it is only
used inside of peers.c make it static.
* Make the declaration of peers_register_table()
match its definition.
* Also, make all functions in peers.c that
are not also in peers.h static
Bashkim Kasa reported that the stats admin page did not work when colons
were used in server or backend names. This was caused by url-encoding
resulting in ':' being sent as '%3A'. Now we systematically decode the
field names and values to fix this issue.
It's more expensive to call splice() on short payloads than to use
recv()+send(). One of the reasons is that doing a splice() involves
allocating a pipe. One other reason is that the kernel will have to
copy itself if we try to splice less than a page. So let's fix a
short offset of 4kB below which we don't splice.
A quick test shows that on chunked encoded data, with splice we had
6826 syscalls (1715 splice, 3461 recv, 1650 send) while with this
patch, the same transfer resulted in 5793 syscalls (3896 recv, 1897
send).
There are some very rare server-to-server applications that abuse the HTTP
protocol and expect the payload phase to be highly interactive, with many
interleaved data chunks in both directions within a single request. This is
absolutely not supported by the HTTP specification and will not work across
most proxies or servers. When such applications attempt to do this through
haproxy, it works but they will experience high delays due to the network
optimizations which favor performance by instructing the system to wait for
enough data to be available in order to only send full packets. Typical
delays are around 200 ms per round trip. Note that this only happens with
abnormal uses. Normal uses such as CONNECT requests nor WebSockets are not
affected.
When "option http-no-delay" is present in either the frontend or the backend
used by a connection, all such optimizations will be disabled in order to
make the exchanges as fast as possible. Of course this offers no guarantee on
the functionality, as it may break at any other place. But if it works via
HAProxy, it will work as fast as possible. This option should never be used
by default, and should never be used at all unless such a buggy application
is discovered. The impact of using this option is an increase of bandwidth
usage and CPU usage, which may significantly lower performance in high
latency environments.
This change should be backported to 1.4 since the first report of such a
misuse was in 1.4. Next patch will also be needed.
This status code is used in response to requests matching "monitor-uri".
Some users need to adjust it to fit their needs (eg: make some strings
appear there). As it's already defined as a chunked string and used
exactly like other status codes, it makes sense to make it configurable
with the usual "errorfile", "errorloc", ...
John Helliwell reported a runtime issue on Solaris since 1.5-dev5. Traces
show that connect() returns EINVAL, which means the socket length is not
appropriate for the family. Solaris does not like being called with sizeof
and needs the address family's size on sockaddr_storage.
The fix consists in adding a get_addr_len() function which returns the
socket's address length based on its family. Tests show that this works
for both IPv4 and IPv6 addresses.
Since IPv6 is a different type than IPv4, the pattern fetch functions
src6 and dst6 were added. IPv6 stick-tables can also fetch IPv4 addresses
with src and dst. In this case, the IPv4 addresses are mapped to their
IPv6 counterpart, according to RFC 4291.
Since the latest additions to buffer_forward(), it became too large for
inlining, so let's uninline it. The code size drops by 3kB. Should be
backported to 1.4 too.
Despite much care around handling the content-length as a 64-bit integer,
forwarding was broken on 32-bit platforms due to the 32-bit nature of
the ->to_forward member of the "buffer" struct. The issue is that this
member is declared as a long, so while it works OK on 64-bit platforms,
32-bit truncate the content-length to the lower 32-bits.
One solution could consist in turning to_forward to a long long, but it
is used a lot in the critical path, so it's not acceptable to perform
all buffer size computations on 64-bit there.
The fix consists in changing the to_forward member to a strict 32-bit
integer and ensure in buffer_forward() that only the amount of bytes
that can fit into it is considered. Callers of buffer_forward() are
responsible for checking that their data were taken into account. We
arbitrarily ensure we never consider more than 2G at once.
That's the way it was intended to work on 32-bit platforms except that
it did not.
This issue was tracked down hard at Exosec with Bertrand Jacquin,
Thierry Fournier and Julien Thomas. It remained undetected for a long
time because files larger than 4G are almost always transferred in
chunked-encoded format, and most platforms dealing with huge contents
these days run on 64-bit.
The bug affects all 1.5 and 1.4 versions, and must be backported.
The parser now distinguishes between pure addresses and address:port. This
is useful for some config items where only an address is required.
Raw IPv6 addresses are now parsed, but IPv6 host name resolution is still not
handled (gethostbyname does not resolve IPv6 names to addresses).
This option enables use of the PROXY protocol with the server, which
allows haproxy to transport original client's address across multiple
architecture layers.
Upon connection establishment, stream_sock is now able to send a PROXY
line before sending any data. Since it's possible that the buffer is
already full, and we don't want to allocate a block for that line, we
compute it on-the-fly when we need it. We just store the offset from
which to (re-)send from the end of the line, since it's assumed that
multiple outputs of the same proxy line will be strictly equivalent. In
practice, one call is enough. We just make sure to handle the case where
the first send() would indicate an incomplete output, eventhough it's
very unlikely to ever happen.
And also rename "req_acl_rule" "http_req_rule". At the beginning that
was a bit confusing to me, especially the "req_acl" list which in fact
holds what we call rules. After some digging, it appeared that some
part of the code is 100% HTTP and not just related to authentication
anymore, so let's move that part to HTTP and keep the auth-only code
in auth.c.
It's very annoying that frontend and backend stats are merged because we
don't know what we're observing. For instance, if a "listen" instance
makes use of a distinct backend, it's impossible to know what the bytes_out
means.
Some points take care of not updating counters twice if the backend points
to the frontend, indicating a "listen" instance. The thing becomes more
complex when we try to add support for server side keep-alive, because we
have to maintain a pointer to the backend used for last request, and to
update its stats. But we can't perform such comparisons anymore because
the counters will not match anymore.
So in order to get rid of this situation, let's have both frontend AND
backend stats in the "struct proxy". We simply update the relevant ones
during activity. Some of them are only accounted for in the backend,
while others are just for frontend. Maybe we can improve a bit on that
later, but the essential part is that those counters now reflect what
they really mean.
This patch turns internal server addresses to sockaddr_storage to
store IPv6 addresses, and makes the connect() function use it. This
code already works but some caveats with getaddrinfo/gethostbyname
still need to be sorted out while the changes had to be merged at
this stage of internal architecture changes. So for now the config
parser will not emit an IPv6 address yet so that user experience
remains unchanged.
This change should have absolutely zero user-visible effect, otherwise
it's a bug introduced during the merge, that should be reported ASAP.
This one has been removed and is now totally superseded by ->target.
To get the server, one must use target_srv(&s->target) instead of
s->srv now.
The function ensures that non-server targets still return NULL.
s->prev_srv is used by assign_server() only, but all code paths leading
to it now take s->prev_srv from the existing s->srv. So assign_server()
can do that copy into its own stack.
If at one point a different srv is needed, we still have a copy of the
last server on which we failed a connection attempt in s->target.
When dealing with HTTP keep-alive, we'll have to know if we can reuse
an existing connection. For that, we'll have to check if the current
connection was made on the exact same target (referenced in the stream
interface).
Thus, we need to first assign the next target to the session, then
copy it to the stream interface upon connect(). Later we'll check for
equivalence between those two operations.
Till now we used the fact that the dispatch address was not null to use
the dispatch mode. This is very unconvenient, so let's have a dedicated
option.
This is in fact where those parts belong to. The old data_state was replaced
by applet.state and is now initialized when the applet is registered. It's
worth noting that the applet does not need to know the session nor the
buffer anymore since everything is brought by the stream interface.
It is possible that having a separate applet struct would simplify the
code but that's not a big deal.
Now that we have the target pointer and type in the stream interface,
we don't need the applet.handler pointer anymore. That makes the code
somewhat cleaner because we know we're dealing with an applet by checking
its type instead of checking the pointer is not null.
When doing a connect() on a stream interface, some information is needed
from the server and from the backend. In some situations, we don't have
a server and only a backend (eg: peers). In other cases, we know we have
an applet and we don't want to connect to anything, but we'd still like
to have the info about the applet being used.
For this, we now store a pointer to the "target" into the stream interface.
The target describes what's on the other side before trying to connect. It
can be a server, a proxy or an applet for now. Later we'll probably have
descriptors for multiple-stage chains so that the final information may
still be found.
This will help removing many specific cases in the code. It already made
it possible to remove the "srv" and "be" parameters to tcpv4_connect_server().
Those 3 parts are the buffer side, the remote side and the communication
functions. This change has no functional effect but is needed to proceed
further.
I/O handlers are still delicate to manipulate. They have no type, they're
just raw functions which have no knowledge of themselves. Let's have them
declared as applets once for all. That way we can have multiple applets
share the same handler functions and we can store their names there. When
we later need to add more parameters (eg: usage stats), we'll be able to
do so in the applets themselves.
The CLI functions has been prefixed with "cli" instead of "stats" as it's
clearly what is going on there.
The applet descriptor in the stream interface should get all the applet
specific data (st0, ...) but this will be done in the next patch so that
we don't pollute this one too much.
Till now, the forwarding code was making use of the hdr_content_len member
to hold the size of the last chunk parsed. As such, it was reset after being
scheduled for forwarding. The issue is that this entry was reset before the
data could be viewed by backend.c in order to parse a POST body, so the
"balance url_param check_post" did not work anymore.
In order to fix this, we need two things :
- the chunk size (reset upon every forward)
- the total body size (not reset)
hdr_content_len was thus replaced by the former (hence the size of the patch)
as it makes more sense to have it stored that way than the way around.
This patch should be backported to 1.4 with care, considering that it affects
the forwarding code.
I have written a small patch to enable a correct PostgreSQL health check
It works similar to mysql-check with the very same parameters.
E.g.:
listen pgsql 127.0.0.1:5432
mode tcp
option pgsql-check user pgsql
server masterdb pgsql.server.com:5432 check inter 10000
One of the requirements we have is to run multiple instances of haproxy on a
single host; this is so that we can split the responsibilities (and change
permissions) between product teams. An issue we ran up against is how we
would distinguish between the logs generated by each instance. The solution
we came up with (please let me know if there is a better way) is to override
the application tag written to syslog. We can then configure syslog to write
these to different files.
I have attached a patch adding a global option 'log-tag' to override the
default syslog tag 'haproxy' (actually defaults to argv[0]).
Haproxy does not include the hostname rather the IP of the machine in
the syslog headers it sends. Unfortunately this means that for each log
line rsyslog does a reverse dns on the client IP and in the case of
non-routable IPs one gets the public hostname not the internal one.
While this is valid according to RFC3164 as one might imagine this is
troublsome if you have some machines with public IPs, internal IPs, no
reverse DNS entries, etc and you want a standardized hostname based log
directory structure. The rfc says the preferred value is the hostname.
This patch adds a global "log-send-hostname" statement which accepts an
optional string to force the host name. If unset, the local host name
is used.
HTTP pipelining currently needs to monitor the response buffer to wait
for some free space to be able to send a response. It was not possible
for the HTTP analyser to be called based on response buffer activity.
Now we introduce a new buffer flag BF_WAKE_ONCE which is set when the
HTTP request analyser is set on the response buffer and some activity
is detected. This is not clean at all but once of the only ways to fix
the issue before we make it possible to register events for analysers.
Also it appeared that one realign condition did not cover all cases.
This counter will help quickly spot whether there are new errors or not.
It is also assigned to each capture so that a script can keep trace of
which capture was taken when.
Debugging parsing errors can be greatly improved if we know what the parser
state was and what the buffer flags were (especially for closed inputs/outputs
and full buffers). Let's add that to the error snapshots.
When the number of servers is a multiple of the size of the input set,
map-based hash can be inefficient. This typically happens with 64
servers when doing URI hashing. The "avalanche" hash-type applies an
avalanche hash before performing a map lookup in order to smooth the
distribution. The result is slightly less smooth than the map for small
numbers of servers, but still better than the consistent hashing.
We'll use this hash at other places, let's make it globally available.
The function has also been renamed because its "chash_hash" name was
not appropriate.
Ross West reported that int32_t breaks compilation on FreeBSD. Since an
int is 32-bit on all supported platforms and we already rely on that,
change the type.
Enhance pattern convs and fetch argument parsing, now fetchs and convs callbacks used typed args.
Add more details on error messages on parsing pattern expression function.
Update existing pattern convs and fetchs to new proto.
Create stick table key type "binary".
Manage Truncation and padding if pattern's fetch-converted result don't match table key size.
MAXPATHLEN may be used at other places, it's unconvenient to have it
redefined in a few files. Also, since checking it requires including
sys/param.h, some versions of it cause a macro declaration conflict
with MIN/MAX which are defined in tools.h. The solution consists in
including sys/param.h in both files so that we ensure it's loaded
before the macros are defined and MAXPATHLEN is checked.
The introduction of a new PROXY protocol for proxied connections requires
an early analyser to decode the incoming connection and set the session
flags accordingly.
Some more work is needed, among which setting a flag on the session to
indicate it's proxied, and copying the original parameters for later
comparisons with new ACLs (eg: real_src, ...).
inetaddr_host_lim_ret() used to make use of const char** for some
args, but that make it impossible ot use char** due to the way
controls are made by gcc. So let's change that.
This option makes haproxy preserve any persistence cookie emitted by
the server, which allows the server to change it or to unset it, for
instance, after a logout request.
(cherry picked from commit 52e6d75374c7900c1fe691c5633b4ae029cae8d5)
The stats web interface must be read-only by default to prevent security
holes. As it is now allowed to enable/disable servers, a new keyword
"stats admin" is introduced to activate this admin level, conditioned by ACLs.
(cherry picked from commit 5334bab92ca7debe36df69983c19c21b6dc63f78)
Based on a patch provided by Judd Montgomery, it is now possible to
enable/disable servers from the stats web interface. This allows to select
several servers in a backend and apply the action to them at the same time.
Currently, there are 2 known limitations :
- The POST data are limited to one packet
(don't alter too many servers at a time).
- Expect: 100-continue is not supported.
(cherry picked from commit 7693948766cb5647ac03b48e782cfee2b1f14491)
If a cookie comes in with a first or last date, and they are configured on
the backend, they're checked. If a date is expired or too far in the future,
then the cookie is ignored and the specific reason appears in the cookie
field of the logs.
(cherry picked from commit faa3019107eabe6b3ab76ffec9754f2f31aa24c6)
These functions only require 5 chars to encode 30 bits, and don't expect
any padding. They will be used to encode dates in cookies.
(cherry picked from commit a7e2b5fc4612994c7b13bcb103a4a2c3ecd6438a)
The set-cookie status flags were not very handy and limited. Reorder
them to save some room for additional values and add the "U" flags
(for Updated expiration date) that will be used with expirable cookies
in insert mode.
(cherry picked from commit 5bab52f821bb0fa99fc48ad1b400769e66196ece)
We'll need one more bit to store and report the request cookie's status.
Doing this required moving a few bits around. However, now in 1.4 all bits
are used, there's no room left.
Cookie flags will need
(cherry picked from commit 09ebca0413c43620ddc375b5b4ab31a25d47b3f4)
In all cookie persistence modes but prefix, we now support cookies whose
value is suffixed with some contents after a vertical bar ('|'). This will
be used to pass an optional expiration date. So as of now we only consider
the part of the cookie value which is used before the vertical bar.
(cherry picked from commit a4486bf4e5b03b5a980d03fef799f6407b2c992d)
Add two new arguments to the "cookie" keyword, to be able to
fix a max idle and max life on them. Right now only the parameter
parsing is implemented.
(cherry picked from commit 9ad5dec4c3bb8f29129f292cb22d3fc495fcc98a)
HTTP content-based health checks will be involved in searching text in pages.
Some pages may not fit in the default buffer (16kB) and sometimes it might be
desired to have larger buffers in order to find patterns. Running checks on
smaller URIs is always preferred of course.
(cherry picked from commit 043f44aeb835f3d0b57626c4276581a73600b6b1)
This patch adds the "http-check expect [r]{string,status}" statements
which enable health checks based on whether the response status or body
to an HTTP request contains a string or matches a regex.
This probably is one of the oldest patches that remained unmerged. Over
the time, several people have contributed to it, among which FinalBSD
(first and second implementations), Nick Chalk (port to 1.4), Anze
Skerlavaj (tests and fixes), Cyril Bont (general fixes), and of course
myself for the final fixes and doc during integration.
Some people already use an old version of this patch which has several
issues, among which the inability to search for a plain string that is
not at the beginning of the data, and the inability to look for response
contents that are provided in a second and subsequent recv() calls. But
since some configs are already deployed, it was quite important to ensure
a 100% compatible behaviour on the working cases.
Thus, that patch fixes the issues while maintaining config compatibility
with already deployed versions.
(cherry picked from commit b507c43a3ce9a8e8e4b770e52e4edc20cba4c37f)
This patch provides a new "option ldap-check" statement to enable
server health checks based on LDAPv3 bind requests.
(cherry picked from commit b76b44c6fed8a7ba6f0f565dd72a9cb77aaeca7c)
There was no consistency between all the functions used to exchange data
between a buffer and a stream interface. Also, the functions used to send
data to a buffer did not consider the possibility that the buffer was
shutdown for read.
Now the functions are called buffer_{put,get}_{char,block,chunk,string}.
The old buffer_feed* functions have been left available for existing code
but marked deprecated.
This counter is incremented for each incoming connection and each active
listener, and is used to prevent haproxy from stopping upon SIGUSR1. It
will thus be possible for some tasks in increment this counter in order
to prevent haproxy from dying until they have completed their job.
Signal zero is never delivered by the system. However having a signal to
which functions and tasks can subscribe to be notified of a stopping event
is useful. So this patch does two things :
1) allow signal zero to be delivered from any function of signal handler
2) make soft_stop() deliver this signal so that tasks can be notified of
a stopping condition.
The two new functions below make it possible to register any number
of functions or tasks to a system signal. They will be called in the
registration order when the signal is received.
struct sig_handler *signal_register_fct(int sig, void (*fct)(struct sig_handler *), int arg);
struct sig_handler *signal_register_task(int sig, struct task *task, int reason);
In case of binding failure during startup, we wait for some time sending
signals to old pids so that they release the ports we need. But if there
aren't any old pids anymore, it's useless to wait, we prefer to fail fast.
Along with this change, we now have the number of old pids really found
in the nb_oldpids variable.
In case of HTTP keepalive processing, we want to release the counters tracked
by the backend. Till now only the second set of counters was released, while
it could have been assigned by the frontend, or the backend could also have
assigned the first set. Now we reuse to unused bits of the session flags to
mark which stick counters were assigned by the backend and to release them as
appropriate.
The assumption that there was a 1:1 relation between tracked counters and
the frontend/backend role was wrong. It is perfectly possible to track the
track-fe-counters from the backend and the track-be-counters from the
frontend. Thus, in order to reduce confusion, let's remove this useless
{fe,be} reference and simply use {1,2} instead. The keywords have also been
renamed in order to limit confusion. The ACL rule action now becomes
"track-sc{1,2}". The ACLs are now "sc{1,2}_*" instead of "trk{fe,be}_*".
That means that we can reasonably document "sc1" and "sc2" (sticky counters
1 and 2) as sort of patterns that are available during the whole session's
life and use them just like any other pattern.
Having a single tracking pointer for both frontend and backend counters
does not work. Instead let's have one for each. The keyword has changed
to "track-be-counters" and "track-fe-counters", and the ACL "trk_*"
changed to "trkfe_*" and "trkbe_*".
It is now possible to dump some select table entries based on criteria
which apply to the stored data. This is enabled by appending the following
options to the end of the "show table" statement :
data.<data_type> {eq|ne|lt|gt|le|ge} <value>
For intance :
show table http_proxy data.conn_rate gt 5
show table http_proxy data.gpc0 ne 0
The compare applies to the integer value as it would be displayed, and
operates on signed long long integers.
It's a bit cumbersome to have to know all possible storable types
from the stats interface. Instead, let's have generic types for
all data, which will facilitate their manipulation.
It is now possible to dump a table's contents with keys, expire,
use count, and various data using the command above on the stats
socket.
"show table" only shows main table stats, while "show table <name>"
dumps table contents, only if the socket level is admin.
This patch adds support for the following session counters :
- http_req_cnt : HTTP request count
- http_req_rate: HTTP request rate
- http_err_cnt : HTTP request error count
- http_err_rate: HTTP request error rate
The equivalent ACLs have been added to check the tracked counters
for the current session or the counters of the current source.
This counter may be used to track anything. Two sets of ACLs are available
to manage it, one gets its value, and the other one increments its value
and returns it. In the second case, the entry is created if it did not
exist.
Thus it is possible for example to mark a source as being an abuser and
to keep it marked as long as it does not wait for the entry to expire :
# The rules below use gpc0 to track abusers, and reject them if
# a source has been marked as such. The track-counters statement
# automatically refreshes the entry which will not expire until a
# 1-minute silence is respected from the source. The second rule
# evaluates the second part if the first one is true, so GPC0 will
# be increased once the conn_rate is above 100/5s.
stick-table type ip size 200k expire 1m store conn_rate(5s),gpc0
tcp-request track-counters src
tcp-request reject if { trk_get_gpc0 gt 0 }
tcp-request reject if { trk_conn_rate gt 100 } { trk_inc_gpc0 gt 0}
Alternatively, it is possible to let the entry expire even in presence of
traffic by swapping the check for gpc0 and the track-counters statement :
stick-table type ip size 200k expire 1m store conn_rate(5s),gpc0
tcp-request reject if { src_get_gpc0 gt 0 }
tcp-request track-counters src
tcp-request reject if { trk_conn_rate gt 100 } { trk_inc_gpc0 gt 0}
It is also possible not to track counters at all, but entry lookups will
then be performed more often :
stick-table type ip size 200k expire 1m store conn_rate(5s),gpc0
tcp-request reject if { src_get_gpc0 gt 0 }
tcp-request reject if { src_conn_rate gt 100 } { src_inc_gpc0 gt 0}
The '0' at the end of the counter name is there because if we find that more
counters may be useful, other ones will be added.
This function looks up a key, updates its expiration date, or creates
it if it was not found. acl_fetch_src_updt_conn_cnt() was updated to
make use of it.
These counters maintain incoming and outgoing byte rates in a stick-table,
over a period which is defined in the configuration (2 ms to 24 days).
They can be used to detect service abuse and enforce a certain bandwidth
limits per source address for instance, and block if the rate is passed
over. Since 32-bit counters are used to compute the rates, it is important
not to use too long periods so that we don't have to deal with rates above
4 GB per period.
Example :
# block if more than 5 Megs retrieved in 30 seconds from a source.
stick-table type ip size 200k expire 1m store bytes_out_rate(30s)
tcp-request track-counters src
tcp-request reject if { trk_bytes_out_rate gt 5000000 }
# cause a 15 seconds pause to requests from sources in excess of 2 megs/30s
tcp-request inspect-delay 15s
tcp-request content accept if { trk_bytes_out_rate gt 2000000 } WAIT_END
These counters maintain incoming connection rates and session rates
in a stick-table, over a period which is defined in the configuration
(2 ms to 24 days). They can be used to detect service abuse and
enforce a certain accept rate per source address for instance, and
block if the rate is passed over.
Example :
# block if more than 50 requests per 5 seconds from a source.
stick-table type ip size 200k expire 1m store conn_rate(5s),sess_rate(5s)
tcp-request track-counters src
tcp-request reject if { trk_conn_rate gt 50 }
# cause a 3 seconds pause to requests from sources in excess of 20 requests/5s
tcp-request inspect-delay 3s
tcp-request content accept if { trk_sess_rate gt 20 } WAIT_END
We're now able to return errors based on the validity of an argument
passed to a stick-table store data type. We also support ARG_T_DELAY
to pass delays to stored data types (eg: for rate counters).
Some data types will require arguments (eg: period for a rate counter).
This patch adds support for such arguments between parenthesis in the
"store" directive of the stick-table statement. Right now only integers
are supported.
When a session tracks a counter, automatically increase the cumulated
connection count. This makes src_updt_conn_cnt() almost useless. In
fact it might still be used to update different tables.
The new "bytes_in_cnt" and "bytes_out_cnt" session counters have been
added. They're automatically updated when session counters are updated.
They can be matched with the "src_kbytes_in" and "src_kbytes_out" ACLs
which apply to the volume per source address. This can be used to deny
access to service abusers.
The new "conn_cur" session counter has been added. It is automatically
updated upon "track XXX" directives, and the entry is touched at the
moment we increment the value so that we don't consider further counter
updates as real updates, otherwise we would end up updating upon completion,
which may not be desired. Probably that some other event counters (eg: HTTP
requests) will have to be updated upon each event though.
This counter can be matched against current session's source address using
the "src_conn_cur" ACL.
The "_cnt" suffix is already used by ACLs to count various data,
so it makes sense to use the same one in "conn_cnt" instead of
"conn_cum" to count cumulated connections.
This is not a problem because no version was emitted with those
keywords.
Thus we'll try to stick to the following rules :
xxxx_cnt : cumulated event count for criterion xxxx
xxxx_cur : current number of concurrent entries for criterion xxxx
xxxx_rate: event rate for criterion xxxx
This patch adds the ability to set a pointer in the session to an
entry in a stick table which holds various counters related to a
specific pattern.
Right now the syntax matches the target syntax and only the "src"
pattern can be specified, to track counters related to the session's
IPv4 source address. There is a special function to extract it and
convert it to a key. But the goal is to be able to later support as
many patterns as for the stick rules, and get rid of the specific
function.
The "track-counters" directive may only be set in a "tcp-request"
statement right now. Only the first one applies. Probably that later
we'll support multi-criteria tracking for a single session and that
we'll have to name tracking pointers.
No counter is updated right now, only the refcount is. Some subsequent
patches will have to bring that feature.
The buffer_feed* functions that are used to send data to buffers did only
support sending contiguous chunks while they're relying on memcpy(). This
patch improves on this by making them able to write in two chunks if needed.
Thus, the buffer_almost_full() function has been improved to really consider
the remaining space and not just what can be written at once.
Sometimes it's necessary to be able to perform some "layer 6" analysis
in the backend. TCP request rules were not available till now, although
documented in the diagram. Enable them in backend now.
Some config parsing functions need to return composite status codes
when they rely on other functions. Let's provide a few such codes
for general use and extend them later.
Some freq counters will have to work on periods different from 1 second.
The original freq counters rely on the period to be exactly one second.
The new ones (freq_ctr_period) let the user define the period in ticks,
and all computations are operated over that period. When reading a value,
it indicates the amount of events over that period too.
We'll need to divide 64 bits by 32 bits with new frequency counters.
Gcc does not know when it can safely do that, but the way we build
our operations let us be sure. So let's provide an optimised version
for that purpose.
This member will be used later when frontends are created on the
fly by some tasks. It will also be usable later if we need to
support multiple config instances for example.
When a connection is closed on a stream interface, some iohandlers
will need to be informed in order to release some resources. This
normally happens upon a shutr+shutw. It is the equivalent of the
fd_delete() call which is done for real sockets, except that this
time we release internal resources.
It can also be used with real sockets because it does not cost
anything else and might one day be useful.
The quote_arg() function can be used to quote an argument or indicate
"end of line" if it's null or empty. It should be useful to more precisely
report location of problems in the configuration.
When an entry already exists, we just need to update its expiration
timer. Let's have a dedicated function for that instead of spreading
open code everywhere.
This change also ensures that an update of an existing sticky session
really leads to an update of its expiration timer, which was apparently
not the case till now. This point needs to be checked in 1.4.
Till now sticky sessions only held server IDs. Now there are other
data types so it is not acceptable anymore to overwrite the server ID
when writing something. The server ID must then only be written from
the caller when appropriate. Doing this has also led to separate
lookup and storage.
This one can be parsed on the "stick-table" after with the "store"
keyword. It will hold the number of connections matching the entry,
for use with ACLs or anything else.
The stick_tables will now be able to store extra data for a same key.
A limited set of extra data types will be defined and for each of them
an offset in the sticky session will be assigned at startup time. All
of this information will be stored in the stick table.
The extra data types will have to be specified after the new "store"
keyword of the "stick-table" directive, which will reserve some space
for them.
pattern.c depended on stick_table while in fact it should be the opposite.
So we move from pattern.c everything related to stick_tables and invert the
dependency. That way the code becomes more logical and intuitive.
The name 'exps' and 'keys' in struct stksess was confusing because it was
the same name as in the table which holds all of them, while they only hold
one node each. Remove the trailing 's' to more clearly identify who's who.
Right now we're only able to store a server ID in a sticky session.
The goal is to be able to store anything whose size is known at startup
time. For this, we store the extra data before the stksess pointer,
using a negative offset. It will then be easy to cumulate multiple
data provided they each have their own offset.
It's very disturbing to see the "denied req" counter increase without
any other session counter moving. In fact, we can't count a rejected
TCP connection as "denied req" as we have not yet instanciated any
session at all. Let's use a new counter for that.
Now we're able to reject connections very early, so we need to use a
different counter for the connections that are received and the ones
that are accepted and converted into sessions, so that the rate limits
can still apply to the accepted ones. The session rate must still be
used to compute the rate limit, so that we can reject undesired traffic
without affecting the rate.
Analysers don't care (and must not care) about a few flags such as
BF_AUTO_CLOSE or BF_AUTO_CONNECT, so those flags should not be listed
in the BF_MASK_STATIC bitmask.
We should also recheck if some buffer flags should be ignored or not
in process_session() when deciding if we must loop again or not.
A new function session_accept() is now called from the lower layer to
instanciate a new session. Once the session is instanciated, the upper
layer's frontent_accept() is called. This one can be service-dependant.
That way, we have a 3-phase accept() sequence :
1) protocol-specific, session-less accept(), which is pointed to by
the listener. It defaults to the generic stream_sock_accept().
2) session_accept() which relies on a frontend but not necessarily
for use in a proxy (eg: stats or any future service).
3) frontend_accept() which performs the accept for the service
offerred by the frontend. It defaults to frontend_accept() which
is really what is used by a proxy.
The TCP/HTTP proxies have been moved to this mode so that we can now rely on
frontend_accept() for any type of session initialization relying on a frontend.
The next step will be to convert the stats to use the same system for the stats.
The conn_retries still lies in the session and its initialization depends
on the backend when it may not yet be known. Let's first move it to the
stream interface.
It's not normal to initialize the server-side stream interface from the
accept() function, because it may change later. Thus, we introduce a new
stream_sock_prepare_interface() function which is called just before the
connect() and which sets all of the stream_interface's callbacks to the
default ones used for real sockets. The ->connect function is also set
at the same instant so that we can easily add new server-side protocols
soon.
The connection timeout stored in the buffer has not been used since the
stream interface were introduced. Let's get rid of it as it's one of the
things that complicate factoring of the accept() functions.
We can disable the monitor-net rules on a listener if this flag is not
set in the listener's options. This will be useful when we don't want
to check that fe->addr is set or not for non-TCP frontends.
The new LI_O_TCP_RULES listener option indicates that some TCP rules
must be checked upon accept on this listener. It is now checked by
the frontend and the L4 rules are evaluated only in this case. The
flag is only set when at least one tcp-req rule is present in the
frontend.
The L4 rules check function has now been moved to proto_tcp.c where
it ought to be.
For a long time we had two large accept() functions, one for TCP
sockets instanciating proxies, and another one for UNIX sockets
instanciating the stats interface.
A lot of code was duplicated and both did not work exactly the same way.
Now we have a stream_sock layer accept() called for either TCP or UNIX
sockets, and this function calls the frontend-specific accept() function
which does the rest of the frontend-specific initialisation.
Some code is still duplicated (session & task allocation, stream interface
initialization), and might benefit from having an intermediate session-level
accept() callback to perform such initializations. Still there are some
minor differences that need to be addressed first. For instance, the monitor
nets should only be checked for proxies and not for other connection templates.
Last, we renamed l->private as l->frontend. The "private" pointer in
the listener is only used to store a frontend, so let's rename it to
eliminate this ambiguity. When we later support detached listeners
(eg: FTP), we'll add another field to avoid the confusion.
The 'client.c' file now only contained frontend-specific functions,
so it has naturally be renamed 'frontend.c'. Same for client.h. This
has also been an opportunity to remove some cross references from
files that should not have depended on it.
In the end, this file should contain a protocol-agnostic accept()
code, which would initialize a session, task, etc... based on an
accept() from a lower layer. Right now there are still references
to TCP.
Some functions which act on generic buffer contents without being
tcp-specific were historically in proto_tcp.c. This concerns ACLs
and RDP cookies. Those have been moved away to more appropriate
locations. Ideally we should create some new files for each layer6
protocol parser. Let's do that later.
Just like we do on health checks, we should consider that ACLs that make
use of buffer data are layer 6 and not layer 4, because we'll soon have
to distinguish between pure layer 4 ACLs (without any buffer) and these
ones.
This ACL was missing in complex setups where the status of a remote site
has to be considered in switching decisions. Until there, using a server's
status in an ACL required to have a dedicated backend, which is a bit heavy
when multiple servers have to be monitored.
The code is now ready to support loading pattern from filesinto trees. For
that, it will be required that the ACL keyword has a flag ACL_MAY_LOOKUP
and that the expr is case sensitive. When that is true, the pattern will
have a flag ACL_PAT_F_TREE_OK to indicate that it is possible to feed the
tree instead of a usual pattern if the parsing function is able to do this.
The tree's root is pre-initialized in the pattern's value so that the
function can easily find it. At that point, if the parsing function decides
to use the tree, it just sets ACL_PAT_F_TREE in the return flags so that
the caller knows the tree has been used and the pattern can be recycled.
That way it will be possible to load some patterns into the tree when it
is compatible, and other ones as linear linked lists. A good example of
this might be IPv4 network entries : right now we support holes in masks,
but this very rare feature is not compatible with binary lookup in trees.
So the parser will be able to decide itself whether the pattern can go to
the tree or not.
If we want to be able to match ACLs against a lot of possible values, we
need to put those values in trees. That will only work for exact matches,
which is normally just what is needed.
Right now, only IPv4 and string matching are planned, but others might come
later.
This is used to disable persistence depending on some conditions (for
example using an ACL matching static files or a specific User-Agent).
You can see it as a complement to "force-persist".
In the configuration file, the force-persist/ignore-persist declaration
order define the rules priority.
Used with the "appsesion" keyword, it can also help reducing memory usage,
as the session won't be hashed the persistence is ignored.
Some servers do not completely conform with RFC2616 requirements for
keep-alive when they receive a request with "Connection: close". More
specifically, they don't bother using chunked encoding, so the client
never knows whether the response is complete or not. One immediately
visible effect is that haproxy cannot maintain client connections alive.
The second issue is that truncated responses may be cached on clients
in case of network error or timeout.
scar Fras Barranco reported this issue on Tomcat 6.0.20, and
Patrik Nilsson with Jetty 6.1.21.
Cyril Bont proposed this smart idea of pretending we run keep-alive
with the server and closing it at the last moment as is already done
with option forceclose. The advantage is that we only change one
emitted header but not the overall behaviour.
Since some servers such as nginx are able to close the connection
very quickly and save network packets when they're aware of the
close negociation in advance, we don't enable this behaviour by
default.
"option http-pretend-keepalive" will have to be used for that, in
conjunction with "option http-server-close".
Using get_ip_from_hdr2() we can look for occurrence #X or #-X and
extract the IP it contains. This is typically designed for use with
the X-Forwarded-For header.
Using "usesrc hdr_ip(name,occ)", it becomes possible to use the IP address
found in <name>, and possibly specify occurrence number <occ>, as the
source to connect to a server. This is possible both in a server and in
a backend's source statement. This is typically used to use the source
IP previously set by a upstream proxy.
The transparent proxy address selection was set in the TCP connect function
which is not the most appropriate place since this function has limited
access to the amount of parameters which could produce a source address.
Instead, now we determine the source address in backend.c:connect_server(),
right after calling assign_server_address() and we assign this address in
the session and pass it to the TCP connect function. This cannot be performed
in assign_server_address() itself because in some cases (transparent mode,
dispatch mode or http_proxy mode), we assign the address somewhere else.
This change will open the ability to bind to addresses extracted from many
other criteria (eg: from a header).
We'll need another flag in the 'options' member close to PR_O_TPXY_*,
and all are used, so let's move this easy one to options2 (which are
already used for SQL checks).
The following patch fixed an issue but brought another one :
296897 [MEDIUM] connect to servers even when the input has already been closed
The new issue is that when a connection is inspected and aborted using
TCP inspect rules, now it is sent to the server before being closed. So
that test is not satisfying. A probably better way is not to prevent a
connection from establishing if only BF_SHUTW_NOW is set but BF_SHUTW
is not. That way, the BF_SHUTW flag is not set if the request has any
data pending, which still fixes the stats issue, but does not let any
empty connection pass through.
Also, as a safety measure, we extend buffer_abort() to automatically
disable the BF_AUTO_CONNECT flag. While it appears to always be OK,
it is by pure luck, so better safe than sorry.
We are seeing both real servers repeatedly going on- and off-line with
a period of tens of seconds. Packet tracing, stracing, and adding
debug code to HAProxy itself has revealed that the real servers are
always responding correctly, but HAProxy is sometimes receiving only
part of the response.
It appears that the real servers are sending the test page as three
separate packets. HAProxy receives the contents of one, two, or three
packets, apparently randomly. Naturally, the health check only
succeeds when all three packets' data are seen by HAProxy. If HAProxy
and the real servers are modified to use a plain HTML page for the
health check, the response is in the form of a single packet and the
checks do not fail.
(...)
I've added buffer and length variables to struct server, and allocated
space with the rest of the server initialisation.
(...)
It seems to be working fine in my tests, and handles check responses
that are bigger than the buffer.
today I've noticed that the stats page still displays v1.3 in the
"Updates" link, due to the PRODUCT_BRANCH value in version.h, then
it's maybe time to send you the result (notice that the patch updates
PRODUCT_BRANCH to "1.4").
--
Cyril Bont
When trying to spot some complex bugs, it's often needed to access
information on stuck sessions, which is quite difficult. This new
command helps one get detailed information about a session, with
flags, timers, states, etc... The buffer data are not dumped yet.
Often we need to understand why some transfers were aborted or what
constitutes server response errors. With those two counters, it is
now possible to detect an unexpected transfer abort during a data
phase (eg: too short HTTP response), and to know what part of the
server response errors may in fact be assigned to aborted transfers.
The bounce realign function was algorithmically good but as expected
it was not cache-friendly. Using it with large requests caused so many
cache thrashing that the function itself could drain 70% of the total
CPU time for only 0.5% of the calls !
Revert back to a standard memcpy() using a specially allocated swap
buffer. We're now back to 2M req/s on pipelined requests.
It is wrong to merge FE and BE stats for a proxy because when we consult a
BE's stats, it reflects the FE's stats eventhough the BE has received no
traffic. The most common example happens with listen instances, where the
backend gets credited for all the trafic even when a use_backend rule makes
use of another backend.
The trash buffer may now be smaller than a buffer because we can tune
it at run time. This causes a risk when we're trying to use it as a
temporary buffer to realign unaligned requests, because we may have to
put up to a full buffer into it.
Instead of doing a double copy, we're now relying on an open-coded
bouncing copy algorithm. The principle is that we move one byte at
a time to its final place, and if that place also holds a byte, then
we move it too, and so on. We finish when we've moved all the buffer.
It limits the number of memory accesses, but since it proceeds one
byte at a time and with random walk, it's not cache friendly and
should be slower than a double copy. However, it's only used in
extreme situations and the difference will not be noticeable.
It has been extensively tested and works reliably.
This is a first attempt to add a maintenance mode on servers, using
the stat socket (in admin level).
It can be done with the following command :
- disable server <backend>/<server>
- enable server <backend>/<server>
In this mode, no more checks will be performed on the server and it
will be marked as a special DOWN state (MAINT).
If some servers were tracking it, they'll go DOWN until the server
leaves the maintenance mode. The stats page and the CSV export also
display this special state.
This can be used to disable the server in haproxy before doing some
operations on this server itself. This is a good complement to the
"http-check disable-on-404" keyword and works in TCP mode.
Support the new syntax (http-request allow/deny/auth) in
http stats.
Now it is possible to use the same syntax is the same like in
the frontend/backend http-request access control:
acl src_nagios src 192.168.66.66
acl stats_auth_ok http_auth(L1)
stats http-request allow if src_nagios
stats http-request allow if stats_auth_ok
stats http-request auth realm LB
The old syntax is still supported, but now it is emulated
via private acls and an aditional userlist.
Add generic authentication & authorization support.
Groups are implemented as bitmaps so the count is limited to
sizeof(int)*8 == 32.
Encrypted passwords are supported with libcrypt and crypt(3), so it is
possible to use any method supported by your system. For example modern
Linux/glibc instalations support MD5/SHA-256/SHA-512 and of course classic,
DES-based encryption.
Implement Base64 decoding with a reverse table.
The function accepts and decodes classic base64 strings, which
can be composed from many streams as long each one is properly
padded, for example: SGVsbG8=IEhBUHJveHk=IQ==
Just as for the req* rules, we can now condition rsp* rules with ACLs.
ACLs match on response, so volatile request information cannot be used.
A warning is emitted if a configuration contains such an anomaly.
From now on, if request filters have ACLs defined, these ACLs will be
evaluated to condition the filter. This will be used to conditionally
remove/rewrite headers based on ACLs.
This function automatically builds a rule, considering the if/unless
statements, and automatically updates the proxy's acl_requires, the
condition's file and line.
Now a server can check the contents of the header X-Haproxy-Server-State
to know how haproxy sees it. The same values as those reported in the stats
are provided :
- up/down status + check counts
- throttle
- weight vs backend weight
- active sessions vs backend sessions
- queue length
- haproxy node name
Currently we cannot easily add headers nor anything to HTTP checks
because the requests are pre-formatted with the last CRLF. Make the
check code add the CRLF itself so that we can later add useful info.
Some converters will need one or several arguments. It's not possible
to write a simple generic parser for that, so let's add the ability
for each converter to support its own argument parser, and call it
to get the arguments when it's specified. If unspecified, the arguments
are passed unmodified as string+len.
The pattern type converters currently support a string arg and a length.
Sometimes we'll prefer to pass them a list or a structure. So let's convert
the string and length into a generic void* and int that each converter may
use as it likes.
Despite what is explicitly stated in HTTP specifications,
browsers still use the undocumented Proxy-Connection header
instead of the Connection header when they connect through
a proxy. As such, proxies generally implement support for
this stupid header name, breaking the standards and making
it harder to support keep-alive between clients and proxies.
Thus, we add a new "option http-use-proxy-header" to tell
haproxy that if it sees requests which look like proxy
requests, it should use the Proxy-Connection header instead
of the Connection header.
This is used to force access to down servers for some requests. This
is useful when validating that a change on a server correctly works
before enabling the server again.
Sometimes we need to be able to change the default kernel socket
buffer size (recv and send). Four new global settings have been
added for this :
- tune.rcvbuf.client
- tune.rcvbuf.server
- tune.sndbuf.client
- tune.sndbuf.server
Those can be used to reduce kernel memory footprint with large numbers
of concurrent connections, and to reduce risks of write timeouts with
very slow clients due to excessive kernel buffering.
We need to improve Connection header handling in the request for it
to support the upcoming keep-alive mode. Now we have two flags which
keep in the session the information about the presence of a
Connection: close and a Connection: keep-alive headers in the initial
request, as well as two others which keep the current state of those
headers so that we don't have to parse them again. Knowing the initial
value is essential to know when the client asked for keep-alive while
we're forcing a close (eg in server-close mode). Also the Connection
request parser is now able to automatically remove single header values
at the same time they are parsed. This provides greater flexibility and
reliability.
All combinations of listen/front/back in all modes and with both
1.0 and 1.1 have been tested.
Some header values might be delimited with spaces, so it's not enough to
compare "close" or "keep-alive" with strncasecmp(). Use word_match() for
that.
Calling this function after http_find_header2() automatically deletes
the current value of the header, and removes the header itself if the
value is the only one. The context is automatically adjusted for a
next call to http_find_header2() to return the next header. No other
change nor test should be made on the transient context though.
While waiting in a keep-alive state for a request, we want to silently
close if we don't get anything. However if we get a partial request it's
different because that means the client has started to send something.
This requires a new transaction flag. It will be used to implement a
distinct timeout for keep-alive and requests.
This change, suggested by Cyril Bont, makes a lot of sense and
would have made it obvious that sessid was not properly initialized
while switching to keep-alive. The code is now cleaner.
The stream_int_cond_close() function was added to preserve the
contents of the response buffer because stream_int_retnclose()
was buggy. It flushed the response instead of flushing the
request. This caused issues with pipelined redirects followed
by error messages which ate the previous response.
This might even have caused object truncation on pipelined
requests followed by an error or by a server redirection.
Now that this is fixed, simply get rid of the now useless
function.
Sometimes it can be desired to return a location which is the same
as the request with a slash appended when there was not one in the
request. A typical use of this is for sending a 301 so that people
don't reference links without the trailing slash. The name of the
new option is "append-slash" and it can be used on "redirect"
statements in prefix mode.
Some message pointers were not usable once the message reached the
HTTP_MSG_DONE state. This is the case for ->som which points to the
body because it is needed to parse chunks. There is one case where
we need the beginning of the message : server redirect. We have to
call http_get_path() after the request has been parsed. So we rely
on ->sol without counting on ->som. In order to achieve this, we're
making ->rq.{u,v} relative to the beginning of the message instead
of the buffer. That simplifies the code and makes it cleaner.
Preliminary tests show this is OK.
Several HTTP analysers used to set those flags to values that
were useful but without considering the possibility that they
were not called again to clean what they did. First, replace
direct flag manipulation with more explicit macros. Second,
enforce a rule stating that any buffer which changes one of
these flags from the default must restore it after completion,
so that other analysers see correct flags.
With both this fix and the previous one about analyser bits,
we should not see any more stuck sessions.
This patch implements default-server support allowing to change
default server options. It can be used in [defaults] or [backend]/[listen]
sections. Currently the following options are supported:
- error-limit
- fall
- inter
- fastinter
- downinter
- maxconn
- maxqueue
- minconn
- on-error
- port
- rise
- slowstart
- weight
Supported informations, available via "tr/td title":
- cap: capabilities (proxy)
- mode: one of tcp, http or health (proxy)
- id: SNMP ID (proxy, socket, server)
- IP (socket, server)
- cookie (backend, server)
There were still several situations leading to CLOSE_WAIT sockets
remaining there forever because some complex transitions were
obviously not caught due to the impossibility to resync changes
between the request and response FSMs.
This patch now centralizes the global transaction state and feeds
it from both request and response transitions. That way, whoever
finishes first, there will be no issue for converging to the correct
state.
Some heavy use of the new debugging function has helped a lot. Maybe
those calls could be removed after some time. First tests are very
positive.
By default we automatically wait for enough data to fill large
packets if buf->to_forward is not null. This causes a problem
with POST/Expect requests which have a data size but no data
immediately available. Instead of causing noticeable delays on
such requests, simply add a flag to disable waiting when sending
requests.
Many times we see a lot of short responses in HTTP (typically 304 on a
reload). It is a waste of network bandwidth to send that many small packets
when we know we can merge them. When we know that another HTTP request is
following a response, we set BF_EXPECT_MORE on the response buffer, which
will turn MSG_MORE on exactly once. That way, multiple short responses can
leave pipelined if their corresponding requests were also pipelined.
This option enables HTTP keep-alive on the client side and close mode
on the server side. This offers the best latency on the slow client
side, and still saves as many resources as possible on the server side
by actively closing connections. Pipelining is supported on both requests
and responses, though there is currently no reason to get pipelined
responses.
This new flag may be set by any user on a stream interface to tell
the underlying protocol that there is no need for lingering on the
socket since we know the other side either received everything or
does not care about what we sent.
This will typically be used with forced server close in HTTP mode,
where we want to quickly close a server connection after receiving
its response. Otherwise the system would prevent us from reusing
the same port for some time.
The body parser will be used in close and keep-alive modes. It follows
the stream to keep in sync with both the request and the response message.
Both chunked transfer-coding and content-length are supported according to
RFC2616.
The multipart/byterange encoding has not yet been implemented and if not
seconded by any of the two other ones, will be forwarded till the close,
as requested by the specification.
Both the request and the response analysers converge into an HTTP_MSG_DONE
state where it will be possible to force a close (option forceclose) or to
restart with a fresh new transaction and maintain keep-alive.
This change is important. All tests are OK but any possible behaviour
change with "option httpclose" might find its root here.
Some wrong operations were performed on buffers, assuming the
offsets were relative to the beginning of the request while they
are relative to the beginning of the buffer. In practice this is
not yet an issue since both are the same... until we add support
for keep-alive.
It's not enough to know if the connection will be in CLOSE or TUNNEL mode,
we still need to know whether we want to read a full message to a known
length or read it till the end just as in TUNNEL mode. Some updates to the
RFC clarify slightly better the corner cases, in particular for the case
where a non-chunked encoding is used last.
Now we also take care of adding a proper "connection: close" to messages
whose size could not be determined.
This state indicates that an HTTP message (request or response) is
complete. This will be used to know when we can re-initialize a
new transaction. Right now we only switch to it after the end of
headers if there is no data. When other analysers are implemented,
we can switch to this state too.
The condition to reuse a connection is when the response finishes
after the request. This will have to be checked when setting the
state.
This code really belongs to the http part since it's transaction-specific.
This will also make it easier to later reinitialize a transaction in order
to support keepalive.
We used to apply a limit to each buffer's size in order to leave
some room to rewrite headers, then we used to remove this limit
once the session switched to a data state.
Proceeding that way becomes a problem with keepalive because we
have to know when to stop reading too much data into the buffer
so that we can leave some room again to process next requests.
The principle we adopt here consists in only relying on to_forward+send_max.
Indeed, both of those data define how many bytes will leave the buffer.
So as long as their sum is larger than maxrewrite, we can safely
fill the buffers. If they are smaller, then we refrain from filling
the buffer. This means that we won't risk to fill buffers when
reading last data chunk followed by a POST request and its contents.
The only impact identified so far is that we must ensure that the
BF_FULL flag is correctly dropped when starting to forward. Right
now this is OK because nobody inflates to_forward without using
buffer_forward().
Up to now, we only had a flag in the session indicating if it had to
work in "connection: close" mode. This is not at all compatible with
keep-alive.
Now we ensure that both sides of a connection act independantly and
only relative to the transaction. The HTTP version of the request
and response is also correctly considered. The connection already
knows several modes :
- tunnel (CONNECT or no option in the config)
- keep-alive (when permitted by configuration)
- server-close (close the server side, not the client)
- close (close both sides)
This change carefully detects all situations to find whether a request
can be fully processed in its mode according to the configuration. Then
the response is also checked and tested to fix corner cases which can
happen with different HTTP versions on both sides (eg: a 1.0 client
asks for explicit keep-alive, and the server responds with 1.1 without
a header).
The mode is selected by a capability elimination algorithm which
automatically focuses on the least capable agent between the client,
the frontend, the backend and the server. This ensures we won't get
undesired situtations where one of the 4 "agents" is not able to
process a transaction.
No "Connection: close" header will be added anymore to HTTP/1.0 requests
or responses since they're already in close mode.
The server-close mode is still not completely implemented. The response
needs to be rewritten as keep-alive before being sent to the client if
the connection was already in server-close (which implies the request
was in keep-alive) and if the response has a content-length or a
transfer-encoding (but only if client supports 1.1).
A later improvement in server-close mode would probably be to detect
some situations where it's interesting to close the response (eg:
redirections with remote locations). But even then, the client might
close by itself.
It's also worth noting that in tunnel mode, no connection header is
affected in either direction. A tunnelled connection should theorically
be notified at the session level, but this is useless since by definition
there will not be any more requests on it. Thus, we don't need to add a
flag into the session right now.
Implement decreasing health based on observing communication between
HAProxy and servers.
Changes in this version 2:
- documentation
- close race between a started check and health analysis event
- don't force fastinter if it is not set
- better names for options
- layer4 support
Changes in this version 3:
- add stats
- port to the current 1.4 tree
In order to support keepalive, we'll have to differentiate
normal sessions from tunnel sessions, which are the ones we
don't want to analyse further.
Those are typically the CONNECT requests where we don't care
about any form of content-length, as well as the requests
which are forwarded on non-close and non-keepalive proxies.
To sum up :
- len : it's now the max number of characters for the value, preventing
garbaged results.
- a new option "prefix" is added, this allows to use dynamic cookie
names (e.g. ASPSESSIONIDXXX).
Previously in the thread, I wanted to use the value found with
"capture cookie" but when i started to update the documentation, I
found this solution quite weird. I've made a small rework to not
depend on "capture cookie".
- There's the posssiblity to define the URL parser mode (path parameters
or query string).
We now set msg->col and msg->sov to the first byte of non-header.
They will be used later when parsing chunks. A new macro was added
to perform size additions on an http_msg in order to limit the risks
of copy-paste in the long term.
During this operation, it appeared that the http_msg struct was not
optimal on 64-bit, so it was re-ordered to fill the holes.
An HTTP message can be decomposed into several sub-states depending
on the transfer-encoding. We'll have to keep these state information
while parsing chunks, so we must extend the values. In order not to
change everything, we'll now consider that anything >= MSG_BODY is
the body, and that the value indicates the precise state. The
MSG_ERROR status which was greater than MSG_BODY was moved for this.
Right now, an HTTP server cannot track a TCP server and vice-versa.
This patch enables proxy tracking without relying on the proxy's mode
(tcp/http/health). It only requires a matching proxy name to exist. The
original function was renamed to findproxy_mode().
It's a pain to enable regparm because ebtree is built in its corner
and does not depend on the rest of the config. This causes no problem
except that if the regparm settings are not exactly similar, then we
can get inconsistent function interfaces and crashes.
One solution realized in this patch consists in externalizing all
compiler settings and changing CONFIG_XXX_REGPARM into CONFIG_REGPARM
so that we ensure that any sub-component uses the same setting. Since
ebtree used a value here and not a boolean, haproxy's config has been
set to use a number too. Both haproxy's core and ebtree currently use
the same copy of the compiler.h file. That way we don't have any issue
anymore when one setting changes somewhere.
All files referencing the previous ebtree code were changed to point
to the new one in the ebtree directory. A makefile variable (EBTREE_DIR)
is also available to use files from another directory.
The ability to build the libebtree library temporarily remains disabled
because it can have an impact on some existing toolchains and does not
appear worth it in the medium term if we add support for multi-criteria
stickiness for instance.
The code part which waits for an HTTP response has been extracted
from the old function. We now have two analysers and the second one
may re-enable the first one when an 1xx response is encountered.
This has been tested and works.
The calls to stream_int_return() that were remaining in the wait
analyser have been converted to stream_int_retnclose().
This patch has 2 goals :
1. I wanted to test the appsession feature with a small PHP code,
using PHPSESSID. The problem is that when PHP gets an unknown session
id, it creates a new one with this ID. So, when sending an unknown
session to PHP, persistance is broken : haproxy won't see any new
cookie in the response and will never attach this session to a
specific server.
This also happens when you restart haproxy : the internal hash becomes
empty and all sessions loose their persistance (load balancing the
requests on all backend servers, creating a new session on each one).
For a user, it's like the service is unusable.
The patch modifies the code to make haproxy also learn the persistance
from the client : if no session is sent from the server, then the
session id found in the client part (using the URI or the client cookie)
is used to associated the server that gave the response.
As it's probably not a feature usable in all cases, I added an option
to enable it (by default it's disabled). The syntax of appsession becomes :
appsession <cookie> len <length> timeout <holdtime> [request-learn]
This helps haproxy repair the persistance (with the risk of losing its
session at the next request, as the user will probably not be load
balanced to the same server the first time).
2. This patch also tries to reduce the memory usage.
Here is a little example to explain the current behaviour :
- Take a Tomcat server where /session.jsp is valid.
- Send a request using a cookie with an unknown value AND a path
parameter with another unknown value :
curl -b "JSESSIONID=12345678901234567890123456789012" http://<haproxy>/session.jsp;jsessionid=00000000000000000000000000000001
(I know, it's unexpected to have a request like that on a live service)
Here, haproxy finds the URI session ID and stores it in its internal
hash (with no server associated). But it also finds the cookie session
ID and stores it again.
- As a result, session.jsp sends a new session ID also stored in the
internal hash, with a server associated.
=> For 1 request, haproxy has stored 3 entries, with only 1 which will be usable
The patch modifies the behaviour to store only 1 entry (maximum).
When processing a GET or HEAD request in close mode, we know we don't
need to read anything anymore on the socket, so we can disable it.
Doing this can save up to 40% of the recv calls, and half of the
epoll_ctl calls.
For this we need a buffer flag indicating that we're not interesting in
reading anymore. Right now, this flag also disables both polled reads.
We might benefit from disabling only speculative reads, but we will need
at least this flag when we want to support keepalive anyway.
Currently we don't disable the flag on completion, but it does not
matter as we close ASAP when performing the shutw().
The fd_list[] used by sepoll was indexed on the fd number and was only
used to store the equivalent of an integer. Changing it to be merged
with fdtab reduces the number of pointer computations, the code size
and some initialization steps. It does not harm other pollers much
either, as only one integer was added to the fdtab array.
Some rarely information are stored in fdtab, making it larger for no
reason (source port ranges, remote address, ...). Such information
lie there because the checks can't find them anywhere else. The goal
will be to move these information to the stream interface once the
checks make use of it.
For now, we move them to an fdinfo array. This simple change might
have improved the cache hit ratio a little bit because a 0.5% of
performance increase has measured.
This can ensure that data is readily available on a socket when
we accept it, but a bug in the kernel ignores the timeout so the
socket can remain pending as long as the client does not talk.
Use with care.
This alone makes a typical HTML stats dump consume 10% CPU less,
because we avoid doing complex printf calls to drop them later.
Only a few common cases have been checked, those which are very
likely to run for nothing.
It is a bit expensive and complex to use to call buffer_feed()
directly from the request parser, and there are risks that some
output messages are lost in case of buffer full. Since most of
these messages are static, let's have a state dedicated to print
these messages and store them in a specific area shared with the
stats in the session. This both reduces code size and risks of
losing output data.
Capture & display more data from health checks, like
strerror(errno) for L4 failed checks or a first line
from a response for L7 successes/failed checks.
Non ascii or control characters are masked with
chunk_htmlencode() (html stats) or chunk_asciiencode() (logs).
Add two functions to encode input chunk replacing
non-printable, non ascii or special characters
with:
"&#%u;" - chunk_htmlencode
"<%02X>" - chunk_asciiencode
Above functions should be used when adding strings, received
from possible unsafe sources, to html stats or logs.
int get_backend_server(const char *bk_name, const char *sv_name,
struct proxy **bk, struct server **sv);
This function scans the list of backends and servers to retrieve the first
backend and the first server with the given names, and sets them in both
parameters. It returns zero if either is not found, or non-zero and sets
the ones it did not found to NULL. If a NULL pointer is passed for the
backend, only the pointer to the server will be updated.
The stats socket can now run at 3 different levels :
- user
- operator (default one)
- admin
These levels are used to restrict access to some information
and commands. Only the admin can clear all stats. A user cannot
clear anything nor access sensible data such as sessions or
errors.
Consistent hashing provides some interesting advantages over common
hashing. It avoids full redistribution in case of a server failure,
or when expanding the farm. This has a cost however, the hashing is
far from being perfect, as we associate a server to a request by
searching the server with the closest key in a tree. Since servers
appear multiple times based on their weights, it is recommended to
use weights larger than approximately 10-20 in order to smoothen
the distribution a bit.
In some cases, playing with weights will be the only solution to
make a server appear more often and increase chances of being picked,
so stats are very important with consistent hashing.
In order to indicate the type of hashing, use :
hash-type map-based (default, old one)
hash-type consistent (new one)
Consistent hashing can make sense in a cache farm, in order not
to redistribute everyone when a cache changes state. It could also
probably be used for long sessions such as terminal sessions, though
that has not be attempted yet.
More details on this method of hashing here :
http://www.spiteful.com/2008/03/17/programmers-toolbox-part-3-consistent-hashing/
Recent "struct chunk rework" introduced a NULL pointer dereference
and now haproxy segfaults if auth is required for stats but not found.
The reason is that size_t cannot store negative values, but current
code assumes that "len < 0" == uninitialized.
This patch fixes it.
There are a few remaining max values that need to move to counters.
Also, the counters are more often used than some config information,
so get them closer to the other useful struct members for better cache
efficiency.
Until now it was required that every custom ID was above 1000 in order to
avoid conflicts. Now we have the list of all assigned IDs and can automatically
pick the first unused one. This means that it is perfectly possible to interleave
automatic IDs with persistent IDs and the parser will automatically allocate
unused values starting with 1.
This patch allows to collect & provide separate statistics for each socket.
It can be very useful if you would like to distinguish between traffic
generate by local and remote users or between different types of remote
clients (peerings, domestic, foreign).
Currently no "Session rate" is supported, but adding it should be possible
if we found it useful.
Doing this, we can remove the last BF_HIJACK user and remove
produce_content(). s->data_source could also be removed but
it is currently used to detect if the stats or a server was
used.
The stats handler used to store internal states in s->ana_state. Now
we only rely on si->st0 in which we can store as many states as we
have possible outputs. This cleans up the stats code a lot and makes
it more maintainable. It has also reduced code size by a few hundred
bytes.
We can simplify the code in the stats functions using buffer_feed_chunk()
instead of buffer_write_chunk(). Let's start with this function. This
patch also fixed an issue where we could dump past the end of the capture
buffer if it is shorter than the captured request.
Calling buffer_shutw() marks the buffer as closed but if it was already
closed in the other direction, the stream interface is not marked as
closed, causing infinite loops.
We took this opportunity to completely remove buffer_shutw() and buffer_shutr()
which have no reason to be used at all and which will always cause trouble
when directly called. The stats occurrence was the last one.
By default, when data is sent over a socket, both the write timeout and the
read timeout for that socket are refreshed, because we consider that there is
activity on that socket, and we have no other means of guessing if we should
receive data or not.
While this default behaviour is desirable for almost all applications, there
exists a situation where it is desirable to disable it, and only refresh the
read timeout if there are incoming data. This happens on sessions with large
timeouts and low amounts of exchanged data such as telnet session. If the
server suddenly disappears, the output data accumulates in the system's
socket buffers, both timeouts are correctly refreshed, and there is no way
to know the server does not receive them, so we don't timeout. However, when
the underlying protocol always echoes sent data, it would be enough by itself
to detect the issue using the read timeout. Note that this problem does not
happen with more verbose protocols because data won't accumulate long in the
socket buffers.
When this option is set on the frontend, it will disable read timeout updates
on data sent to the client. There probably is little use of this case. When
the option is set on the backend, it will disable read timeout updates on
data sent to the server. Doing so will typically break large HTTP posts from
slow lines, so use it with caution.
The "static-rr" is just the old round-robin algorithm. It is still
in use when a hash algorithm is used and the data to hash is not
present, but it was impossible to configure it explicitly. This one
is cheaper in terms of CPU and supports unlimited numbers of servers,
so it makes sense to be able to use it.
LB algo macros were composed of the LB algo by itself without any indication
of the method to use to look up a server (the lb function itself). This
method was implied by the LB algo, which was not very convenient to add
more algorithms. Now we have several fields in the LB macros, some to
describe what to look for in the requests, some to describe how to transform
that (kind of algo) and some to describe what lookup function to use.
The next patch will make it possible to factor out some code for all algos
which rely on a map.
The lbprm structure has moved to backend.h, where it should be, and
all algo-specific types and declarations have moved to their specific
files. The proxy struct is now much more readable.
This patch implements "description" (proxy and global) and "node" (global)
options, removes "node-name" and adds "show-node" & "show-desc" options
for "stats". It also changes the way the header lines (with proxy name) and
the statistics are displayed, so stats no longer look so clumsy with very
long names.
Instead of "node-name" it is possible to use show-node/show-desc with
an optional parameter that overrides a default node/description.
backend cust-0045
# report specific values for this customer
stats show-node Europe
stats show-desc Master node for Europe, Asia, Africa
We need to remove hash map accesses out of backend.c if we want to
later support new hash methods. This patch separates the hash computation
method from the server lookup. It leaves the lookup function to lb_map.c
and calls it with the result of the hash.
It was becoming painful to have all the LB algos in backend.c.
Let's move them to their own files. A few hashing functions still
need be broken in two parts, one for the contents and one for the
map position.
This patch adds health logging so it possible to check what
was happening before a crash. Failed healt checks are logged if
server is UP and succeeded healt checks if server is DOWN,
so the amount of additional information is limited.
I also reworked the code a little:
- check_status_description[] and check_status_info[] is now
joined into check_statuses[]
- set_server_check_status updates not only s->check_status and
s->check_duration but also s->result making the code simpler
Changes in v3:
- for now calculate and use local versions of health/rise/fall/state,
it is a slow path, no harm should be done. One day we may centralize
processing of the checks and remove the duplicated code.
- also log checks that are restoring current state
- use "conditionally succeeded" for 404 with disable-on-404
There is no reason to inline functions which are used to grab a server
depending on an LB algo. They are large and used at several places.
Uninlining them saves 400 bytes of code.
We can get rid of the stats analyser by moving all the stats code
to a stream interface applet. Above being cleaner, it provides new
advantages such as the ability to process requests and responses
from the same function and work only with simple state machines.
There's no need for any hijack hack anymore.
The direct advantage for the user are the interactive mode and the
ability to chain several commands delimited by a semi-colon. Now if
the user types "prompt", he gets a prompt from which he can send
as many requests as he wants. All outputs are terminated by a
blank line followed by a new prompt, so this can be used from
external tools too.
The code is not very clean, it needs some rework, but some part
of the dirty parts are due to the remnants of the hijack mode used
in the old functions we call.
The old AN_REQ_STATS_SOCK analyser flag is now unused and has been
removed.
iohandlers will need to store some form of context and for this will
need a way to find their call context. We add the ->private as well
as ->st0 and ->st1 for that purpose. Most likely ->private will be
initialized to the current session and ->st0 and ->st1 will be used
to maintain any form of internal state between calls.
It will soon be necessary to have stream interfaces running as part of
the current task, or as independant tasks. For instance when we want to
implement compression or SSL. It will also be used for applets running
as stream interfaces.
These new functions are used to perform exactly that. Note that it's
still not easy to write a simple echo applet and more functions will
likely be needed.
When stream interfaces will embedded applets running as part as their
holding task, we'll need a new callback to process them from the
session processor.
We had to add a new stream_interface flag : SI_FL_DONT_WAKE. This flag
is used to indicate that a stream interface is being updated and that
no wake up should be sent to its owner. This will be required for tasks
embedded into stream interfaces. Otherwise, we could have the
owner task send wakeups to itself during status updates, thus
preventing the state from converging. As long as a stream_interface's
status is being monitored and adjusted, there is no reason to wake it
up again, as we know its changes will be seen and considered.
Those two functions did not correctly deal with full buffers and/or
buffers that wrapped around. Buffer_skip() was even able to incorrectly
set buf->w further than the end of buffer if its len argument was wrong,
and buffer_si_getline() was able to incorrectly return a length larger
than the effective buffer data available.
It's important that these functions set these flags themselves, otherwise
the callers will always have to do this, and there is no valid reason for
not doing it.
Collect information about last health check result,
including L7 code if possible (for example http or smtp
return code) and time took to finish last check.
Health check info is provided on both stats pages (html & csv)
and logged when a server is marked UP or DOWN. Currently active
check are marked with an asterisk, but only in html mode.
Currently there are 14 status codes:
UNK -> unknown
INI -> initializing
SOCKERR -> socket error
L4OK -> check passed on layer 4, no upper layers testing enabled
L4TOUT -> layer 1-4 timeout
L4CON -> layer 1-4 connection problem, for example "Connection refused"
(tcp rst) or "No route to host" (icmp)
L6OK -> check passed on layer 6
L6TOUT -> layer 6 (SSL) timeout
L6RSP -> layer 6 invalid response - protocol error
L7OK -> check passed on layer 7
L7OKC -> check conditionally passed on layer 7, for example
404 with disable-on-404
L7TOUT -> layer 7 (HTTP/SMTP) timeout
L7RSP -> layer 7 invalid response - protocol error
L7STS -> layer 7 response error, for example HTTP 5xx
In TCP, we don't want to forward chunks of data, we want to forward
indefinitely. This patch introduces a special value for the amount
of data to be forwarded. When buffer_forward() is called with
BUF_INFINITE_FORWARD, it configures the buffer to never stop
forwarding until the end.
The BF_EMPTY flag was once used to indicate an empty buffer. However,
it was used half the time as meaning the buffer is empty for the reader,
and half the time as meaning there is nothing left to send.
"nothing to send" is only indicated by "->send_max=0 && !pipe". Once
we fix this, we discover that the flag is not used anymore. So the
flags has been renamed BF_OUT_EMPTY and means exactly the condition
above, ie, there is nothing to send.
Doing so has allowed us to remove some unused tests for emptiness,
but also to uncover a certain amount of situations where the flag
was not correctly set or tested.
The BF_WRITE_ENA buffer flag became very complex to deal with, because
it was used to :
- enable automatic connection
- enable close forwarding
- enable data forwarding
The last point was not very true anymore since we introduced ->send_max,
but still the test remained everywhere. This was causing issues such as
impossibility to connect without forwarding data, impossibility to prevent
closing when data was forwarded, etc...
This patch clarifies the situation by getting rid of this multi-purpose
flag and replacing it with :
- data forwarding based only on ->send_max || ->pipe ;
- a new BF_AUTO_CONNECT flag to allow automatic connection and only
that ;
- ability to perform an automatic connection when ->send_max or ->pipe
indicate that data is waiting to leave the buffer ;
- a new BF_AUTO_CLOSE flag to let the producer automatically set the
BF_SHUTW_NOW flag when it gets a BF_SHUTR.
During this cleanup, it was discovered that some tests were performed
twice, or that the BF_HIJACK flag was still tested, which is not needed
anymore since ->send_max replcaed it. These places have been fixed too.
These cleanups have also revealed a few areas where the other flags
such as BF_EMPTY are not cleanly used. This will be an opportunity for
a second patch.
By inlining this function and slightly reordering it, we can double
the getchar/putchar test throughput, and reduce its footprint by about
40 bytes. Also, it was the only non-inlined char-based function, which
now makes it more consistent this time.
This function is used to cut the "tail" of a buffer, which means strip it
to the length of unsent data only, and kill any remaining unsent data. Any
scheduled forwarding is stopped. This is mainly to be used to send error
messages after existing data. It does the same as buffer_erase() for buffers
without pending outgoing data.
The computations in buffer_forward() were only valid if buffer_forward()
was used on a buffer which had no more data scheduled for forwarding.
This is always the case right now so this bug is not yet triggered but
it will soon be. Now we correctly discount the bytes to be forwarded
from the data already present in the buffer.
This function works like a traditional putchar() except that it
can return 0 if the output buffer is full.
Now a basic character-based echo function would look like this, from
a stream interface :
while (1) {
c = buffer_si_peekchar(req);
if (c < 0)
break;
if (!buffer_si_putchar(res, c)) {
si->flags |= SI_FL_WAIT_ROOM;
break;
}
buffer_skip(req, 1);
req->flags |= BF_WRITE_PARTIAL;
res->flags |= BF_READ_PARTIAL;
}
The buffer_si_peekline() function is sort of a fgets() to be used from a
stream interface. It returns a complete line whenever possible, and does
not update the buffer's pointer, so that the reader is free to consume
what it wants to.
buffer_si_peekchar() only returns one character, and also needs a call
to buffer_skip() once the character is definitely consumed.
This functions act like their buffer_write*() counter-parts,
except that they're specifically designed to be used from a
stream interface handler, as they carefully check size limits
and automatically advance the read pointer depending on the
to_forward attribute.
buffer_feed_chunk() is an inline calling buffer_feed() as both
are the sames. For this reason, buffer_write_chunk() has also
been turned into an inline which calls buffer_write().
buffer_contig_space(), buffer_contig_data() and buffer_skip()
provide easy methods to extract/insert data from/into a buffer.
buffer_write() and buffer_write_chunk() currently do not check
max_len nor to_forward, so they will quickly become embarrassing
to use or will need an equivalent. The reason is that they are
used to build error messages which currently are not subject to
analysis.
This flag was incorrectly used as meaning "close immediately",
while it needs to say "close ASAP". ASAP here means when unsent
data pending in the buffer are sent. This helps cleaning up some
dirty tricks where the buffer output was checking the BF_SHUTR
flag combined with EMPTY and other such things. Now we have a
clearly defined semantics :
- producer sets SHUTR and *may* set SHUTW_NOW if WRITE_ENA is
set, otherwise leave it to the session processor to set it.
- consumer only checks SHUTW_NOW to decide whether or not to
call shutw().
This also induced very minor changes at some locations which were
not protected against buffer changes while the SHUTW_NOW flag was
set. Now we prevent send_max from changing when the flag is set.
Several tests have been run without any unexpected behaviour detected.
Some more cleanups are needed, as it clearly appears that some tests
could be removed with stricter semantics.
send() supports the MSG_MORE flag on Linux, which does the same
as TCP_CORK except that we don't have to remove TCP_NODELAY before
and we don't need any syscall to set/remove it. This can save up
to 4 syscalls around a send() (two for setting it, two for removing
it), and it's much cleaner since it is not persistent. So make use
of it instead.
We used to call stream_sock_data_finish() directly at the end of
a session update, but if we want to support non-socket interfaces,
we need to have this function configurable. Now we access it via
->update().
The new tune.bufsize and tune.maxrewrite global directives allow one to
change the buffer size and the maxrewrite size. Right now, setting bufsize
too low will block stats sockets which will not be able to write at all.
An error checking must be added to buffer_write_chunk() so that if it
cannot write its message to an empty buffer, it causes the caller to abort.
The first step towards dynamic buffer size consists in removing
all static definitions of the buffer size. Instead, we store a
buffer's size in itself. Right now they're all preinitialized
to BUFSIZE, but we will change that.
sess_establish() used to resort to protocol-specific guesses
in order to set rep->analysers. This is no longer needed as it
gets set from the frontend and the backend as a copy of what
was defined in the configuration.
Analyser bitmaps are now stored in the frontend and backend, and
combined at configuration time. That way, set_session_backend()
does not need to perform any protocol-specific combinations.
Since the listener is the one indicating what analyser and session
handlers to call, it makes sense that it also sets the task's nice
value. This also helps getting rid of the last trace of the stats
in the proto_uxst file.
The remains of the stats socket code has nothing to do in proto_uxst
anymore and must move to dumpstats. The code is much cleaner and more
structured. It was also an opportunity to rename AN_REQ_UNIX_STATS
as AN_REQ_STATS_SOCK as the stats socket is no longer unix-specific
either.
The last item refering to stats in proto_uxst is the setting of the
task's nice value which should in fact come from the listener.
process_session() is now ready to handle unix stats sockets. This
first step works and old code has not been removed. A cleanup is
required. The stats handler is not unix socket-centric anymore and
should move to dumpstats.c.
Creating a frontend for the global stats socket will help merge
unix sockets management with the other socket management. Since
frontends are huge structs, we only allocate it if required.
The connection establishment was completely handled by backend.c which
normally just handles LB algos. Since it's purely TCP, it must move to
proto_tcp.c. Also, instead of calling it directly, we now call it via
the stream interface, which will later help us unify session handling.
This Linux-specific option was never really used in production and
has since been superseded by new splicing options brought by recent
Linux kernels.
It caused several particular cases in the code because the kernel
would take care of the session without haproxy being able to do
anything on it, which became hard to handle in the new architecture.
Let's simply get rid of it now that there is a replacement available.
The new "node-name" stats setting enables reporting of a node ID on
the stats page. It is possible to return the system's host name as
well as a specific name.
The new statement "persist rdp-cookie" enables RDP cookie
persistence. The RDP cookie is then extracted from the RDP
protocol, and compared against available servers. If a server
matches the RDP cookie, then it gets the connection.
This patch adds support for hashing RDP cookies in order to
use them as a load-balancing key. The new "rdp-cookie(name)"
load-balancing metric has to be used for this. It is still
mandatory to wait for an RDP cookie in the frontend, otherwise
it will randomly work.
The RDP protocol is quite simple and documented, which permits
an easy detection and extraction of cookies. It can be useful
to match the MSTS cookie which can contain the username specified
by the client.
This patch propagates the ACL conditions' "requires" bitfield
to the proxies. This makes it possible to know exactly what a
proxy might have to support for any request, which helps knowing
whether we have to allocate some space for certain types of
structures or not (eg: the hdr_idx struct).
The concept might be extended to a lot more types of information,
such as detecting whether we need to allocate some space for some
request ACLs which need a result in the response, etc...
The HTTP processing has been splitted into 7 steps, one of which
is not anymore HTTP-specific (content-switching). That way, it
becomes possible to use "use_backend" rules in TCP mode. A new
"use_server" directive should follow soon.
Some stream analysers might become generic enough to be called
for several bits. So we cannot have the analyser bit hard coded
into the analyser itself. Let's make the caller inform the callee.
We want to split several steps in HTTP processing so that
we can call individual analysers depending on what processing
we want to perform. The first step consists in splitting the
part that waits for a request from the rest.
The splice code did not consider compatibility between both ends
of the connection. Now we set different capabilities on each
stream interface, depending on what the protocol can splice to/from.
Right now, only TCP is supported. Thanks to this, we're now able to
automatically detect when splice() is not implemented and automatically
disable it on one end instead of reporting errors to the upper layer.
When the nolinger option is used, we must not close too fast because
some data might be left unsent. Instead we must proceed with a normal
shutdown first, then a close. Also, we want to avoid merging FIN with
the last segment if nolinger is set, because if that one gets lost,
there is no chance for it to be retransmitted.
We now support up to 10 distinct configuration files. They are
all loaded in the order defined by -f <file1> -f <file2> ...
This can be useful in order to store global, private, public,
etc... configurations in distinct files.
This is a first step towards support of multiple configuration files.
Now readcfgfile() only reads a file in memory and performs very minimal
parsing. The checks are performed afterwards.
Sometimes it can be useful to limit the advertised TCP MSS on
incoming connections, for instance when requests come through
a VPN or when the system is running with jumbo frames enabled.
Passing the "mss <value>" arguments to a "bind" line will set
the value. This works under Linux >= 2.6.28, and maybe a few
earlier ones, though due to an old kernel bug most of earlier
versions will probably ignore it. It is also possible that some
other OSes will support this.
This new option enables combining of request buffer data with
the initial ACK of an outgoing TCP connection. Doing so saves
one packet per connection which is quite noticeable on workloads
mostly consisting in small objects. The option is not enabled by
default.
Setting TCP_CORK on a socket before sending the last segment enables
automatic merging of this segment with the FIN from the shutdown()
call. Playing with TCP_CORK is not easy though as we have to track
the status of the TCP_NODELAY flag since both are mutually exclusive.
Doing so saves one more packet per session and offers about 5% more
performance.
There is no reason not to do it, so there is no associated option.
This option disables TCP quick ack upon accept. It is also
automatically enabled in HTTP mode, unless the option is
explicitly disabled with "no option tcp-smart-accept".
This saves one packet per connection which can bring reasonable
amounts of bandwidth for servers processing small requests.
Sometimes we would want to implement implicit default options,
but for this we need to be able to disable them, which requires
to keep track of "no option" settings. With this change, an option
explicitly disabled in a defaults section will still be seen as
explicitly disabled. There should be no regression as nothing makes
use of this yet.
Some users are already hitting the 64k source port limit when
connecting to servers. The system usually maintains a list of
unused source ports, regardless of the source IP they're bound
to. So in order to go beyond the 64k concurrent connections, we
have to manage the source ip:port lists ourselves.
The solution consists in assigning a source port range to each
server and use a free port in that range when connecting to that
server, either for a proxied connection or for a health check.
The port must then be put back into the server's range when the
connection is closed.
This mechanism is used only when a port range is specified on
a server. It makes it possible to reach 64k connections per
server, possibly all from the same IP address. Right now it
should be more than enough even for huge deployments.
Some users want to keep the max sessions/s seen on servers, frontends
and backends for capacity planning. It's easy to grab it while the
session count is updated, so let's keep it.
Some people are using haproxy in a shared environment where the
system logger by default sends alert and emerg messages to all
consoles, which happens when all servers go down on a backend for
instance. These people can not always change the system configuration
and would like to limit the outgoing messages level in order not to
disturb the local users.
The addition of an optional 4th field on the "log" line permits
exactly this. The minimal log level ensures that all outgoing logs
will have at least this level. So the logs are not filtered out,
just set to this level.
There is a patch made by me that allow for balancing on any http header
field.
[WT:
made minor changes:
- turned 'balance header name' into 'balance hdr(name)' to match more
closely the ACL syntax for easier future convergence
- renamed the proxy structure fields header_* => hh_*
- made it possible to use the domain name reduction to any header, not
only "host" since it makes sense to do it with other ones.
Otherwise patch looks good.
/WT]
Some big traffic sites have trouble dealing with logs and tend to
disable them. Here are two new options to help cope with massive
logs.
- dontlog-normal only disables logging for 100% successful
connections, other ones will still be logged
- log-separate-errors will cause non-100% successful connections
to be logged at level "err" instead of level "info" so that a
properly configured syslog daemon can send them to a different
file for longer conservation.
These functions will be used to deliver asynchronous signals in order
to make the signal handling functions more robust. The goal is to keep
the same interface to signal handlers.
I have attached a patch which will add on every http request a new
header 'X-Original-To'. If you have HAProxy running in transparent mode
with a big number of SQUID servers behind it, it is very nice to have
the original destination ip as a common header to make decisions based
on it.
The whole thing is configurable with a new option 'originalto'. I have
updated the sourcecode as well as the documentation. The 'haproxy-en.txt'
and 'haproxy-fr.txt' files are untouched, due to lack of my french
language knowledge. ;)
Also the patch adds this header for IPv4 only. I haven't any IPv6 test
environment running here and don't know if getsockopt() with SO_ORIGINAL_DST
will work on IPv6. If someone knows it and wants to test it I can modify
the diff. Feel free to ask me questions or things which should be changed. :)
--Maik
The byte counters have long been 64-bit to avoid overflows. But with
several sites nowadays, we see session counters wrap around every 10-days
or so. So it was the moment to switch counters to 64-bit, including
error and warning counters which can theorically rise as fast as session
counters even if in practice there is very low risk.
The performance impact should not be noticeable since those counters are
only updated once per session. The stats output have been carefully checked
for proper types on both 32- and 64-bit platforms.
It's useful to be able to accept an invalid header name in a request
or response but still be able to monitor further such errors. Now,
when an invalid request/response is received and accepted due to
an "accept-invalid-http-{request|response}" option, the invalid
request will be captured for later analysis with "show errors" on
the stats socket.
Sometimes it is required to let invalid requests pass because
applications sometimes take time to be fixed and other servers
do not care. Thus we provide two new options :
option accept-invalid-http-request (for the frontend)
option accept-invalid-http-response (for the backend)
When those options are set, invalid requests or responses do
not cause a 403/502 error to be generated.
This function sets CSS letter spacing after each 3rd digit. The page must
create a class "rls" (right letter spacing) with style "letter-spacing: 0.3em"
in order to use it.
When the reader does not expect to read lots of data, it can
set BF_READ_DONTWAIT on the request buffer. When it is set,
the stream_sock_read callback will not try to perform multiple
reads, it will return after only one, and clear the flag.
That way, we can immediately return when waiting for an HTTP
request without trying to read again.
On pure request/responses schemes such as monitor-uri or
redirects, this has completely eliminated the EAGAIN occurrences
and the epoll_ctl() calls, resulting in a performance increase of
about 10%. Similar effects should be observed once we support
HTTP keep-alive since we'll immediately disable reads once we
get a full request.
If we get very large data at once, it's almost certain that it's
worthless trying to read again, because we got everything we could
get.
Doing this has made all -EAGAIN disappear from splice reads. The
threshold has been put in the global tunable structures so that if
we one day want to make it accessible from user config, it will be
easy to do so.
It's sometimes useful at least for statistics to keep a task count.
It's easy to do by forcing the rare task creators to always use the
same functions to create/destroy a task.
The top of a duplicate tree is not where bit == -1 but at the most
negative bit. This was causing tasks to be queued in reverse order
within duplicates. While this is not dramatic, it's incorrect and
might lead to longer than expected duplicate depths under some
circumstances.
Since we're now able to search from a precise expiration date in
the timer tree using ebtree 4.1, we don't need to maintain 4 trees
anymore. Not only does this simplify the code a lot, but it also
ensures that we can always look 24 days back and ahead, which
doubles the ability of the previous scheduler. Indeed, while based
on absolute values, the timer tree is now relative to <now> as we
can always search from <now>-31 bits.
The run queue uses the exact same principle now, and is now simpler
and a bit faster to process. With these changes alone, an overall
0.5% performance gain was observed.
Tests were performed on the few wrapping cases and everything works
as expected.
In order to get termination flags properly updated, the session was
relying a bit too much on http_return_srv_error() which is http-centric.
A generic srv_error function was implemented in the session in order to
catch all connection abort situations. It was then noticed that a request
abort during a connection attempt was not reported, which is now fixed.
Read and write errors/timeouts were not logged either. It was necessary
to add those tests at 4 new locations.
Now it looks like everything is correctly logged. Most likely some error
checking code could now be removed from some analysers.
There are some configurations in which redirect rules are declared
after use_backend rules. We can also find "block" rules after any
of these ones. The processing sequence is :
- block
- redirect
- use_backend
So as of now we try to detect wrong ordering to warn the user about
a possibly undesired behaviour.
Most of the time, task_queue() will immediately return. By extracting
the preliminary checks and putting them in an inline function, we can
significantly reduce the number of calls to the function itself, and
most of the tests can be optimized away due to the caller's context.
Another minor improvement in process_runnable_tasks() consisted in
taking benefit from the processor's branch prediction unit by making
a special case of the process_session() callback which is by far the
most common one.
All this improved performance by about 1%, mainly during the call
from process_runnable_tasks().
Timers are unsigned and used as tree positions. Ticks are signed and
used as absolute date within current time frame. While the two are
normally equal (except zero), it's important not to confuse them in
the code as they are not interchangeable.
We add two inline functions to turn each one into the other.
The comments have also been moved to the proper location, as it was
not easy to understand what was a tick and what was a timer unit.
All the tasks callbacks had to requeue the task themselves, and update
a global timeout. This was not convenient at all. Now the API has been
simplified. The tasks callbacks only have to update their expire timer,
and return either a pointer to the task or NULL if the task has been
deleted. The scheduler will take care of requeuing the task at the
proper place in the wait queue.
In many situations, we wake a task on an I/O event, then queue it
exactly where it was. This is a real waste because we delete/insert
tasks into the wait queue for nothing. The only reason for this is
that there was only one tree node in the task struct.
By adding another tree node, we can have one tree for the timers
(wait queue) and one tree for the priority (run queue). That way,
we can have a task both in the run queue and wait queue at the
same time. The wait queue now really holds timers, which is what
it was designed for.
The net gain is at least 1 delete/insert cycle per session, and up
to 2-3 depending on the workload, since we save one cycle each time
the expiration date is not changed during a wake up.
The rate-limit was applied to the smoothed value which does a special
case for frequencies below 2 events per period. This caused irregular
limitations when set to 1 session per second.
The proper way to handle this is to compute the number of remaining
events that can occur without reaching the limit. This is what has
been added. It also has the benefit that the frequency calculation
is now done once when entering event_accept(), before the accept()
loop, and not once per accept() loop anymore, thus saving a few CPU
cycles during very high loads.
With this fix, rate limits of 1/s are perfectly respected.
The new "rate-limit sessions" statement sets a limit on the number of
new connections per second on the frontend. As it is extremely accurate
(about 0.1%), it is efficient at limiting resource abuse or DoS.
With this change, all frontends, backends, and servers maintain a session
counter and a timer to compute a session rate over the last second. This
value will be very useful because it varies instantly and can be used to
check thresholds. This value is also reported in the stats in a new "rate"
column.
Several algorithms will need to know the millisecond value within
the current second. Instead of doing a divide every time it is needed,
it's better to compute it when it changes, which is when now and now_ms
are recomputed.
curr_sec_ms_scaled is the same multiplied by 2^32/1000, which will be
useful to compute some ratios based on the position within last second.
The new "show errors" command sent on a unix socket will dump
all captured request and response errors for all proxies. It is
also possible to bound the log to frontends and backends whose
ID is passed as an optional parameter.
The output provides information about frontend, backend, server,
session ID, source address, error type, and error position along
with a complete dump of the request or response which has caused
the error.
If a new error scratches the one currently being reported, then
the dump is aborted with a warning message, and processing goes
on to next error.
Each proxy instance, either frontend or backend, now has some room
dedicated to storing a complete dated request or response in case
of parsing error. This will make it possible to consult errors in
order to find the exact cause, which is particularly important for
troubleshooting faulty applications.
The "bind-process" keyword lets the admin select which instances may
run on which process (in multi-process mode). It makes it easier to
more evenly distribute the load across multiple processes by avoiding
having too many listen to the same IP:ports.
Specifying "interface <name>" after the "source" statement allows
one to bind to a specific interface for proxy<->server traffic.
This makes it possible to use multiple links to reach multiple
servers, and to force traffic to pass via an interface different
from the one the system would have chosen based on the routing
table.
By appending "interface <name>" to a "bind" line, it is now possible
to specifically bind to a physical interface name. Note that this
currently only works on Linux and requires root privileges.
Setting "nosplice" in the global section will disable the use of TCP
splicing (both tcpsplice and linux 2.6 splice). The same will be
achieved using the "-dS" parameter on the command line.
The global tuning options right now only concern the polling mechanisms,
and they are not in the global struct itself. It's not very practical to
add other options so let's move them to the global struct and remove
types/polling.h which was not used for anything else.
Using pipe pools makes pipe management a lot easier. It also allows to
remove quite a bunch of #ifdefs in areas which depended on the presence
or not of support for kernel splicing.
The buffer now holds a pointer to a pipe structure which is always NULL
except if there are still data in the pipe. When it needs to use that
pipe, it dynamically allocates it from the pipe pool. When the data is
consumed, the pipe is immediately released.
That way, there is no need anymore to care about pipe closure upon
session termination, nor about pipe creation when trying to use
splice().
Another immediate advantage of this method is that it considerably
reduces the number of pipes needed to use splice(). Tests have shown
that even with 0.2 pipe per connection, almost all sessions can use
splice(), because the same pipe may be used by several consecutive
calls to splice().
A new data type has been added : pipes. Some pre-allocated empty pipes
are maintained in a pool for users such as splice which use them a lot
for very short times.
Pipes are allocated using get_pipe() and released using put_pipe().
Pipes which are released with pending data are immediately killed.
The struct pipe is small (16 to 20 bytes) and may even be further
reduced by unifying ->data and ->next.
It would be nice to have a dedicated cleanup task which would watch
for the pipes usage and destroy a few of them from time to time.
When CONFIG_HAP_LINUX_SPLICE is defined, the buffer structure will be
slightly enlarged to support information needed for kernel splicing
on Linux.
A first attempt consisted in putting this information into the stream
interface, but in the long term, it appeared really awkward. This
version puts the information into the buffer. The platform-dependant
part is conditionally added and will only enlarge the buffers when
compiled in.
One new flag has also been added to the buffers: BF_KERN_SPLICING.
It indicates that the application considers it is appropriate to
use splicing to forward remaining data.
Three new options have been added when CONFIG_HAP_LINUX_SPLICE is
set :
- splice-request
- splice-response
- splice-auto
They are used to enable splicing per frontend/backend. They are also
supported in defaults sections. The "splice-auto" option is meant to
automatically turn splice on for buffers marked as fast streamers.
This should save quite a bunch of file descriptors.
It was required to add a new "options2" field to the proxy structure
because the original "options" is full.
When global.maxpipes is not set, it is automatically adjusted to
the max of the sums of all frontend's and backend's maxconns for
those which have at least one splice option enabled.
In the buffers, the read limit used to leave some place for header
rewriting was set by a pointer to the end of the buffer. Not only
this required subtracts at every place in the code, but this will
also soon not be usable anymore when we want to support keepalive.
Let's replace this with a length limit, comparable to the buffer's
length. This has also sightly reduced the code size.
The way the buffers and stream interfaces handled ->to_forward was
really not handy for multiple reasons. Now we've moved its control
to the receive-side of the buffer, which is also responsible for
keeping send_max up to date. This makes more sense as it now becomes
possible to send some pre-formatted data followed by forwarded data.
The following explanation has also been added to buffer.h to clarify
the situation. Right now, tests show that the I/O is behaving extremely
well. Some work will have to be done to adapt existing splice code
though.
/* Note about the buffer structure
The buffer contains two length indicators, one to_forward counter and one
send_max limit. First, it must be understood that the buffer is in fact
split in two parts :
- the visible data (->data, for ->l bytes)
- the invisible data, typically in kernel buffers forwarded directly from
the source stream sock to the destination stream sock (->splice_len
bytes). Those are used only during forward.
In order not to mix data streams, the producer may only feed the invisible
data with data to forward, and only when the visible buffer is empty. The
consumer may not always be able to feed the invisible buffer due to platform
limitations (lack of kernel support).
Conversely, the consumer must always take data from the invisible data first
before ever considering visible data. There is no limit to the size of data
to consume from the invisible buffer, as platform-specific implementations
will rarely leave enough control on this. So any byte fed into the invisible
buffer is expected to reach the destination file descriptor, by any means.
However, it's the consumer's responsibility to ensure that the invisible
data has been entirely consumed before consuming visible data. This must be
reflected by ->splice_len. This is very important as this and only this can
ensure strict ordering of data between buffers.
The producer is responsible for decreasing ->to_forward and increasing
->send_max. The ->to_forward parameter indicates how many bytes may be fed
into either data buffer without waking the parent up. The ->send_max
parameter says how many bytes may be read from the visible buffer. Thus it
may never exceed ->l. This parameter is updated by any buffer_write() as
well as any data forwarded through the visible buffer.
The consumer is responsible for decreasing ->send_max when it sends data
from the visible buffer, and ->splice_len when it sends data from the
invisible buffer.
A real-world example consists in part in an HTTP response waiting in a
buffer to be forwarded. We know the header length (300) and the amount of
data to forward (content-length=9000). The buffer already contains 1000
bytes of data after the 300 bytes of headers. Thus the caller will set
->send_max to 300 indicating that it explicitly wants to send those data,
and set ->to_forward to 9000 (content-length). This value must be normalised
immediately after updating ->to_forward : since there are already 1300 bytes
in the buffer, 300 of which are already counted in ->send_max, and that size
is smaller than ->to_forward, we must update ->send_max to 1300 to flush the
whole buffer, and reduce ->to_forward to 8000. After that, the producer may
try to feed the additional data through the invisible buffer using a
platform-specific method such as splice().
*/
In preparation of splice support, let's add the splice_len member
to the buffer struct. An earlier implementation made it conditional,
which made the whole logics very complex due to a large number of
ifdefs.
Now BF_EMPTY is only set once both buf->l and buf->splice_len are
null. Splice_len is initialized to zero during buffer creation and
is currently not changed, so the whole logics remains unaffected.
When splice gets merged, splice_len will reflect the number of bytes
in flight out of the buffer but not yet sent, typically in a pipe for
the Linux case.
