These two new statements allow to pass information extracted from the request
to the server. It's particularly useful for passing SSL information to the
server, but may be used for various other purposes such as combining headers
together to emulate internal variables.
These macros (U2H, U2A, LIM2A, ...) have been used with an explicit
index for the local storage variable, making it difficult to change
log formats and causing a few issues from time to time. Let's have
a single macro with a rotating index so that up to 10 conversions
may be used in a single call.
At the moment, we need trash chunks almost everywhere and the only
correctly implemented one is in the sample code. Let's move this to
the chunks so that all other places can use this allocator.
Additionally, the get_trash_chunk() function now really returns two
different chunks. Previously it used to always overwrite the same
chunk and point it to a different buffer, which was a bit tricky
because it's not obvious that two consecutive results do alias each
other.
The dumpstats code looks like a spaghetti plate. Several functions are
supposed to be able to do several things but rely on complex states to
dispatch the work to independant functions. Most of the HTML output is
performed within the switch/case statements of the whole state machine.
Let's clean this up by adding new functions to emit the data and have
a few more iterators to avoid relying on so complex states.
The new stats dump sequence looks like this for CLI and for HTTP :
cli_io_handler()
-> stats_dump_sess_to_buffer() // "show sess"
-> stats_dump_errors_to_buffer() // "show errors"
-> stats_dump_raw_info_to_buffer() // "show info"
-> stats_dump_raw_info()
-> stats_dump_raw_stat_to_buffer() // "show stat"
-> stats_dump_csv_header()
-> stats_dump_proxy()
-> stats_dump_px_hdr()
-> stats_dump_fe_stats()
-> stats_dump_li_stats()
-> stats_dump_sv_stats()
-> stats_dump_be_stats()
-> stats_dump_px_end()
http_stats_io_handler()
-> stats_http_redir()
-> stats_dump_http() // also emits the HTTP headers
-> stats_dump_html_head() // emits the HTML headers
-> stats_dump_csv_header() // emits the CSV headers (same as above)
-> stats_dump_http_info() // note: ignores non-HTML output
-> stats_dump_proxy() // same as above
-> stats_dump_http_end() // emits HTML trailer
Using %[expression] it becomes possible to make the log engine fetch
some samples from the request or the response and provide them in the
logs. Note that this feature is still limited, it does not yet allow
to apply converters, to limit the output length, nor to specify the
direction which should be fetched when a fetch function works in both
directions.
However it's quite convenient to log SSL information or to include some
information that are used in stick tables.
It is worth noting that this has been done in the generic log format
handler, which means that the same information may be used to build the
unique-id header and to pass the information to a backend server.
The log-format parser reached a limit making it hard to add new features.
It also suffers from a weak handling of certain incorrect corner cases,
for example "%{foo}" is emitted as a litteral while syntactically it's an
argument to no variable. Also the argument parser had to redo some of the
job with some cases causing minor memory leaks (eg: ignored args).
This work aims at improving the situation so that slightly better reporting
is possible and that it becomes possible to extend the log format. The code
has a few more states but looks significantly simpler. The parser is now
capable of reporting ignored arguments and truncated lines.
stream_int_chk_rcv_conn() did not clear connection flags before updating them. It
is unsure whether this could have caused the stalled transfers that have been
reported since dev15.
In order to avoid such further issues, we now use a simple inline function to do
all the job.
Looking at the assembly code that updt_fd() and alloc/release_spec_entry
produce in the polling loops, it's clear that gcc has to recompute pointers
several times in a row because of limited spare registers. By better
grouping adjacent structure updates, we improve the code size by around
60 bytes in the fast path on x86.
The stick counters were in two distinct sets of struct members,
causing some code to be duplicated. Now we use an array, which
enables some processing to be performed in loops. This allowed
the code to be shrunk by 700 bytes.
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.
