When commit 477902bd2e made the conn_stream
allocation unconditional, it unfortunately moved the code doing the allocation
inside #if USE_OPENSSL, which means anybody compiling haproxy without
openssl wouldn't allocate any conn_stream, and would get a segfault later.
Fix that by moving the code that does the allocation outside #if USE_OPENSSL.
As mentioned in commit c192b0ab95 ("MEDIUM: connection: remove
CO_FL_CONNECTED and only rely on CO_FL_WAIT_*"), there is a lack of
consistency on which flags are checked among L4/L6/HANDSHAKE depending
on the code areas. A number of sample fetch functions only check for
L4L6 to report MAY_CHANGE, some places only check for HANDSHAKE and
many check both L4L6 and HANDSHAKE.
This patch starts to make all of this more consistent by introducing a
new mask CO_FL_WAIT_XPRT which is the union of L4/L6/HANDSHAKE and
reports whether the transport layer is ready or not.
All inconsistent call places were updated to rely on this one each time
the goal was to check for the readiness of the transport layer.
Most places continue to check CO_FL_HANDSHAKE while in fact they should
check CO_FL_HANDSHAKE_NOSSL, which contains all handshakes but the one
dedicated to SSL renegotiation. In fact the SSL layer should be the
only one checking CO_FL_SSL_WAIT_HS, so as to avoid processing data
when a renegotiation is in progress, but other ones randomly include it
without knowing. And ideally it should even be an internal flag that's
not exposed in the connection.
This patch takes CO_FL_SSL_WAIT_HS out of CO_FL_HANDSHAKE, uses this flag
consistently all over the code, and gets rid of CO_FL_HANDSHAKE_NOSSL.
In order to limit the confusion that has accumulated over time, the
CO_FL_SSL_WAIT_HS flag which indicates an ongoing SSL handshake,
possibly used by a renegotiation was moved after the other ones.
Commit 477902bd2e ("MEDIUM: connections: Get ride of the xprt_done
callback.") broke the master CLI for a very obscure reason. It happens
that short requests immediately terminated by a shutdown are properly
received, CS_FL_EOS is correctly set, but in si_cs_recv(), we refrain
from setting CF_SHUTR on the channel because CO_FL_CONNECTED was not
yet set on the connection since we've not passed again through
conn_fd_handler() and it was not done in conn_complete_session(). While
commit a8a415d31a ("BUG/MEDIUM: connections: Set CO_FL_CONNECTED in
conn_complete_session()") fixed the issue, such accident may happen
again as the root cause is deeper and actually comes down to the fact
that CO_FL_CONNECTED is lazily set at various check points in the code
but not every time we drop one wait bit. It is not the first time we
face this situation.
Originally this flag was used to detect the transition between WAIT_*
and CONNECTED in order to call ->wake() from the FD handler. But since
at least 1.8-dev1 with commit 7bf3fa3c23 ("BUG/MAJOR: connection: update
CO_FL_CONNECTED before calling the data layer"), CO_FL_CONNECTED is
always synchronized against the two others before being checked. Moreover,
with the I/Os moved to tasklets, the decision to call the ->wake() function
is performed after the I/Os in si_cs_process() and equivalent, which don't
care about this transition either.
So in essence, checking for CO_FL_CONNECTED has become a lazy wait to
check for (CO_FL_WAIT_L4_CONN | CO_FL_WAIT_L6_CONN), but that always
relies on someone else having synchronized it.
This patch addresses it once for all by killing this flag and only checking
the two others (for which a composite mask CO_FL_WAIT_L4L6 was added). This
revealed a number of inconsistencies that were purposely not addressed here
for the sake of bisectability:
- while most places do check both L4+L6 and HANDSHAKE at the same time,
some places like assign_server() or back_handle_st_con() and a few
sample fetches looking for proxy protocol do check for L4+L6 but
don't care about HANDSHAKE ; these ones will probably fail on TCP
request session rules if the handshake is not complete.
- some handshake handlers do validate that a connection is established
at L4 but didn't clear CO_FL_WAIT_L4_CONN
- the ->ctl method of mux_fcgi, mux_pt and mux_h1 only checks for L4+L6
before declaring the mux ready while the snd_buf function also checks
for the handshake's completion. Likely the former should validate the
handshake as well and we should get rid of these extra tests in snd_buf.
- raw_sock_from_buf() would directly set CO_FL_CONNECTED and would only
later clear CO_FL_WAIT_L4_CONN.
- xprt_handshake would set CO_FL_CONNECTED itself without actually
clearing CO_FL_WAIT_L4_CONN, which could apparently happen only if
waiting for a pure Rx handshake.
- most places in ssl_sock that were checking CO_FL_CONNECTED don't need
to include the L4 check as an L6 check is enough to decide whether to
wait for more info or not.
It also becomes obvious when reading the test in si_cs_recv() that caused
the failure mentioned above that once converted it doesn't make any sense
anymore: having CS_FL_EOS set while still waiting for L4 and L6 to complete
cannot happen since for CS_FL_EOS to be set, the other ones must have been
validated.
Some of these parts will still deserve further cleanup, and some of the
observations above may induce some backports of potential bug fixes once
totally analyzed in their context. The risk of breaking existing stuff
is too high to blindly backport everything.
objt_conn() may return a NULL though here we don't have this situation
anymore since the connection is always there, so let's simply switch
to the unchecked __objt_conn(). This addresses issue #454.
Coverity rightfully reported that it's pointless to test for "conn"
to be null while all code paths leading to it have already
dereferenced it. This addresses issue #461.
The xprt_done_cb callback was used to defer some connection initialization
until we're connected and the handshake are done. As it mostly consists of
creating the mux, instead of using the callback, introduce a conn_create_mux()
function, that will just call conn_complete_session() for frontend, and
create the mux for backend.
In h2_wake(), make sure we call the wake method of the stream_interface,
as we no longer wakeup the stream task.
In connect_server(), when creating a new connection for which we don't yet
know the mux (because it'll be decided by the ALPN), instead of associating
the connection to the stream_interface, always create a conn_stream. This way,
we have less special-casing needed. Store the conn_stream in conn->ctx,
so that we can reach the upper layers if needed.
Currently there's still lots of code in conn_complete_server() that performs
one half of the connection setup, which is then checked and finalized in
back_handle_st_con(). There isn't a valid reason for this anymore, we can
simplify this and make sure that conn_complete_server() only wakes the stream
up to inform it about the fact the whole connection stack is set up so that
back_handle_st_con() finishes its job at the stream-int level.
It looks like the there could even be further simplified, but for now it
was moved straight out of conn_complete_server() with no modification.
For more than a decade we've kept all the sess_update_st_*() functions
in stream.c while they're only there to work in relation with what is
currently being done in backend.c (srv_redispatch_connect, connect_server,
etc). Let's move all this pollution over there and take this opportunity
to try to find slightly less confusing names for these old functions
whose role is only to handle transitions from one specific stream-int
state:
sess_update_st_rdy_tcp() -> back_handle_st_rdy()
sess_update_st_con_tcp() -> back_handle_st_con()
sess_update_st_cer() -> back_handle_st_cer()
sess_update_stream_int() -> back_try_conn_req()
sess_prepare_conn_req() -> back_handle_st_req()
sess_establish() -> back_establish()
The last one remained in stream.c because it's more or less a completion
function which does all the initialization expected on a connection
success or failure, can set analysers and emit logs.
The other ones could possibly slightly benefit from being modified to
take a stream-int instead since it's really what they're working with,
but it's unimportant here.
In connect_server(), when we decide we want to kill the connection of
another thread because there are too many idle connections, hold the
toremove_lock of the corresponding thread, othervise, there's a small race
condition where we could try to add the connection to the toremove_connections
list while it has already been free'd.
This should be backported to 2.0 and 2.1.
Runtime traces are now supported for the streams, only if compiled with
debug. process_stream() is covered as well as TCP/HTTP analyzers and filters.
In traces, the first argument is always a stream. So it is easy to get the info
about the channels and the stream-interfaces. The second argument, when defined,
is always a HTTP transaction. And the third one is an HTTP message. The trace
message is adapted to report HTTP info when possible.
The sample fetche can get srv_name without foreach
`core.backends["bk"].servers`.
Then we can get Server class quickly via
`core.backends[txn.f:be_name()].servers[txn.f:srv_name()]`.
Issue#342
In connect_server(), if we're reusing a connection, only use SF_SRV_REUSED
if the connection is fully ready. We may be using a multiplexed connection
created by another stream that is not yet ready, and may fail.
If we set SF_SRV_REUSED, process_stream() will then not wait for the timeout
to expire, and retry to connect immediately.
This should be backported to 1.9 and 2.0.
This commit depends on 55234e33708c5a584fb9efea81d71ac47235d518.
Instead of using the same type for regular linked lists and "autolocked"
linked lists, use a separate type, "struct mt_list", for the autolocked one,
and introduce a set of macros, similar to the LIST_* macros, with the
MT_ prefix.
When we use the same entry for both regular list and autolocked list, as
is done for the "list" field in struct connection, we know have to explicitely
cast it to struct mt_list when using MT_ macros.
In the function connect_server(), when we are not able to reuse a connection and
too many FDs are opened, the variable srv must be defined to kill an idle
connection.
This patch fixes the issue #257. It must be backported to 2.0
The converter can be useful to look up a server queue from a dynamic value.
It takes an input value of type string, either a server name or
<backend>/<server> format and returns the number of queued sessions
on that server. Can be used in places where we want to look up
queued sessions from a dynamic name, like a cookie value (e.g.
req.cook(SRVID),srv_queue) and then make a decision to break
persistence or direct a request elsewhere.
Signed-off-by: Nenad Merdanovic <nmerdan@haproxy.com>
Now that we start by releasing any possibly existing connection,
the conditions simplify a little bit and some of the complex cases
can be removed. A few comments were also added for non-obvious cases.
When entering connect_server() we're not supposed to have a connection
already, except when retrying a failed connection, which is pretty rare.
Let's simplify the code by starting to unconditionally release any existing
connection. For now we don't go further, as this change alone will lead to
quite some simplification that'd rather be done as a separate cleanup.
When forcing the outgoing address of a connection, till now we used to
allocate this outgoing connection and set the address into it, then set
SF_ADDR_SET. With connection reuse this causes a whole lot of issues and
difficulties in the code.
Thanks to the previous changes, it is now possible to store the target
address into the stream instead, and copy the address from the stream to
the connection when initializing the connection. assign_server_address()
does this and as a result SF_ADDR_SET now reflects the presence of the
target address in the stream, not in the connection. The http_proxy mode,
the peers and the master's CLI now use the same mechanism. For now the
existing connection code was not removed to limit the amount of tricky
changes, but the allocated connection is not used anymore.
This change also revealed a latent issue that we've been having around
option http_proxy : the address was set in the connection but neither the
SF_ADDR_SET nor the SF_ASSIGNED flags were set. It looks like the connection
could establish only due to the fact that it existed with a non-null
destination address.
Now that we have dynamically allocated addresses, there's no need to
clear an address before reusing it, just release it. Note that this
is not equivalent to saying that an address is never zero, as shown in
assign_server_address() where an address 0.0.0.0 can still be assigned
to a connection for the time it takes to modify it.
This commit places calls to sockaddr_alloc() at the places where an address
is needed, and makes sure that the allocation is properly tested. This does
not add too many error paths since connection allocations are already in the
vicinity and share the same error paths. For the two cases where a
clear_addr() was called, instead the address was not allocated.
All reads were carefully reviewed for only reading already checked
values. Assignments were commented indicating that an allocation will
be needed once they become dynamic. The memset() used to clear the
addresses should then be turned to a free() and a NULL assignment.
The backend connect code uses conn_get_{from,to}_addr to forward addresses
in transparent mode and to map server ports, without really checking if the
operation succeeds. In preparation of future changes, let's switch to
conn_get_{src,dst}() and integrate status check for possible failures.
The old module proto_http does not exist anymore. All code dedicated to the HTTP
analysis is now grouped in the file proto_htx.c. So, to finish the polishing
after removing the legacy HTTP code, proto_htx.{c,h} files have been moved in
http_ana.{c,h} files.
In addition, all HTX analyzers and related functions prefixed with "htx_" have
been renamed to start with "http_" instead.
The L7 loadbalancing algorithms are concerned (uri, url_param and hdr), the
"sni" parameter on the server line and the "source" parameter on the server line
when used with "use_src hdr_ip()".
If si_connect() failed, do not try to install the mux nor to complete
the operations or add the connection to an idle list, and abort quickly
instead. No obvious side effects were identified, but continuing to
allocate some resources after something has already failed seems risky.
This was a result of a prior fix which already wanted to push this code
further : aa089d80b ("BUG/MEDIUM: server: Defer the mux init until after
xprt has been initialized.") but it ought to have pushed it even further
to maintain the error check just after si_connect().
To be backported to 2.0 and 1.9.
In connect_server(), if there were already a CS assosciated with the stream,
but we can't reuse it, because the target is different (because we tried a
previous connection, it failed, and we use redispatch so we switched servers),
don't forget to set srv_cs to NULL. Otherwise, if we end up reusing another
connection, we would consider we already have a conn_stream, and we won't
create a new one, so we'd have a new connection but we would not be able to
use it.
This can explain frozen streams and connections stuck in CLOSE_WAIT when
using redispatch.
This should be backported to 1.9 and 2.0.
In connect_server(), we used to only call xprt_add_hs() if CO_FL_SEND_PROXY
was set during the function call, we would not do it if the flag was set
before connect_server() was called. The rational at the time was if the flag
was already set, then the XPRT was already present. But now the xprt_handshake
always removes itself, so we have to re-add it each time, or it wouldn't be
done if the first connection attempt failed.
While I'm there, check any non-ssl handshake flag, instead of just
CO_FL_SEND_PROXY, or we'd miss the SOCKS4 flags.
This should be backported to 2.0.
In connect_server(), if we don't yet have a mux, because we're choosing
one depending on the ALPN, don't attempt to send early data. We can't do
it because those data would depend on the mux, that will only be determined
by the handshake.
This should be backported to 1.9.
In connect_server(), don't wait until we negociate the ALPN to choose the
mux, the only mux we want to use is the mux_pt anyway.
This should be backported to 1.9.
Add a new XPRT that is used when using non-SSL handshakes, such as proxy
protocol or Netscaler, instead of taking care of it in conn_fd_handler().
This XPRT is installed when any of those is used, and it removes itself once
the handshake is done.
This should allow us to remove the distinction between CO_FL_SOCK* and
CO_FL_XPRT*.
In connect_server(), when deciding if we should attempt to remove idle
connections, because we have to many file descriptors opened, don't attempt
to do so if idle connection pool is disabled (with pool-max-conn 0), as
if it is, srv->idle_orphan_conns won't even be allocated, and trying to
dereference it will cause a crash.
Have "socks4" and "check-via-socks4" server keyword added.
Implement handshake with SOCKS4 proxy server for tcp stream connection.
See issue #82.
I have the "SOCKS: A protocol for TCP proxy across firewalls" doc found
at "https://www.openssh.com/txt/socks4.protocol". Please reference to it.
[wt: for now connecting to the SOCKS4 proxy over unix sockets is not
supported, and mixing IPv4/IPv6 is discouraged; indeed, the control
layer is unique for a connection and will be used both for connecting
and for target address manipulation. As such it may for example report
incorrect destination addresses in logs if the proxy is reached over
IPv6]
Add session flags, and add a new flag, SESS_FL_PREFER_LAST, to be set when
we use NTLM authentication, and we should reuse the last connection. This
should fix using NTLM with HTX. This totally replaces TX_PREFER_LAST.
This should be backported to 1.9.
The first block is the start-line, if defined. Otherwise it the head of the HTX
message. So now, during HTTP analysis, lookup are all done using the first block
instead of the head. Concretely, for now, it is the same because only one HTTP
message is stored at a time in an HTX message. 1xx informational messages are
handled separatly from the final reponse and from each other. But it will make
sense when the 1xx informational messages and the associated final reponse will
be stored in the same HTX message.
Now, we only return the start-line. If not found, NULL is returned. No lookup is
performed and the HTX message is no more updated. It is now the caller
responsibility to update the position of the start-line to the right value. So
when it is not found, i.e sl_pos is set to -1, it means the last start-line has
been already processed and the next one has not been inserted yet.
It is mandatory to rely on this kind of warranty to store 1xx informational
responses and final reponse in the same HTX message.
Since commit 88698d9 ("MEDIUM: connections: Add a way to control the
number of idling connections.") when building without threads, gcc
complains that the operations made on the idle_orphan_conns[] list is
out of bounds, which is always false since 1) <i> can only equal zero,
and 2) given it's equal to <tid> we never even enter the loop. But as
usual it thinks it knows better, so let's mask the origin of this <i>
value to shut it up. Another solution consists in making <i> unsigned
and adding an explicit range check.
It's always a pain to have to stuff lots of #ifdef USE_OPENSSL around
ssl headers, it even results in some of them appearing in a random order
and multiple times just to benefit form an existing ifdef block. Let's
make these headers safe for inclusion when USE_OPENSSL is not defined,
they now perform the test themselves and do nothing if USE_OPENSSL is
not defined. This allows to remove no less than 8 such ifdef blocks
and make include blocks more readable.
They were all check to comply with the advertised openssl version. Now
that libressl doesn't pretend to be a more recent openssl anymore, we
can simply rely on the regular openssl version tests without having to
deal with exceptions for libressl.
Most tests on OPENSSL_VERSION_NUMBER have become complex and break all
the time because this number is fake for some derivatives like LibreSSL.
This patch creates a new macro, HA_OPENSSL_VERSION_NUMBER, which will
carry the real openssl version defining the compatibility level, and
this version will be adjusted depending on the variants.
Libressl doesn't yet provide early data, so don't put the CO_FL_EARLY_SSL_HS
on the connection if we're building with libressl, or the handshake will
never be done.
Add a new keyword for retry-on, 0rtt-rejected. If set, we will try to
replay requests for which we sent early data that got rejected by the
server.
If that option is set, we will attempt to use 0rtt if "allow-0rtt" is set
on the server line even if the client didn't send early data.
When for some reason the session is not the owner of the connection anymore,
make sure we remove CO_FL_SESS_IDLE, even if we're about to call
conn->mux->destroy(), as the destroy may not destroy the connection
immediately if it's still in use.
This should be backported to 1.9.
u
Don't know why it happens now, but gcc seems to think srv_conn may be NULL when
a reused connection is removed from the orphan list. It happens when HAProxy is
compiled with -O2 with my gcc (8.3.1) on fedora 29... Changing a little how
reuse parameter is tested removes the warnings. So...
This patch may be backported to 1.9.
As by default we add all keepalive connections to the idle pool, if we run
into a pathological case, where all client don't do keepalive, but the server
does, and haproxy is configured to only reuse "safe" connections, we will
soon find ourself having lots of idling, unusable for new sessions, connections,
while we won't have any file descriptors available to create new connections.
To fix this, add 2 new global settings, "pool_low_ratio" and "pool_high_ratio".
pool-low-fd-ratio is the % of fds we're allowed to use (against the maximum
number of fds available to haproxy) before we stop adding connections to the
idle pool, and destroy them instead. The default is 20. pool-high-fd-ratio is
the % of fds we're allowed to use (against the maximum number of fds available
to haproxy) before we start killing idling connection in the event we have to
create a new outgoing connection, and no reuse is possible. The default is 25.
It is mandatory to handle mux upgrades, because during a mux upgrade, the
connection will be reassigned to another multiplexer. So when the old one is
destroyed, it does not own the connection anymore. Or in other words, conn->ctx
does not point to the old mux's context when its destroy() callback is
called. So we now rely on the multiplexer context do destroy it instead of the
connection.
In addition, h1_release() and h2_release() have also been updated in the same
way.
Since LIST_DEL_LOCKED() and LIST_POP_LOCKED() now automatically reinitialize
the removed element, there's no need for keeping this LIST_INIT() call in the
idle connection code.
Instead of having one task per thread and per server that does clean the
idling connections, have only one global task for every servers.
That tasks parses all the servers that currently have idling connections,
and remove half of them, to put them in a per-thread list of connections
to kill. For each thread that does have connections to kill, wake a task
to do so, so that the cleaning will be done in the context of said thread.
Use the locked macros when manipulating idle_orphan_conns, so that other
threads can remove elements from it.
It will be useful later to avoid having a task per server and per thread to
cleanup the orphan list.
Add a per-thread counter of idling connections, and use it to determine
how many connections we should kill after the timeout, instead of using
the global counter, or we're likely to just kill most of the connections.
This should be backported to 1.9.
Use atomic operations when dealing with srv->curr_idle_conns, as it's shared
between threads, otherwise we could get inconsistencies.
This should be backported to 1.9.
A piece of code about the HTX was lost this summer, after the "big merge"
(htx/http2/connection layer refactoring). I forgot to keep HTX changes in the
functions connect_server() and assign_server(). So, this patch fixes "uri",
"url_param" and "hdr" LB algorithms when the HTX is enabled. It also fixes
evaluation of the "sni" expression on server lines.
This issue was reported on github. See issue #32.
This patch must be backported in 1.9.
Commit 3c4e19f42 ("BUG/MEDIUM: backend: always release the previous
connection into its own target srv_list") introduced a valid warning
about a null-deref risk since we didn't check conn_new()'s return value.
This patch must be backported to 1.9 with the patch above.
There was a bug reported in issue #19 regarding the fact that haproxy
could mis-route requests to the wrong server. It turns out that when
switching to another server, the old connection was put back into the
srv_list corresponding to the stream's target instead of this connection's
target. Thus if this connection was later picked, it was pointing to the
wrong server.
The patch fixes this and also clarifies the assignment to srv_conn->target
so that it's clear we don't change it when picking it from the srv_list.
This must be backported to 1.9 only.
If we failed to install the mux, just close the connection, or
conn_fd_handler() will be called for the FD, and crash as soon as it attempts
to access the mux' wake method.
This should be backported to 1.9.
If we failed to add the connection to the session, only try to add it back
to the server idle list if it has a mux, otherwise the connection is
incomplete and unusable.
This should be backported to 1.9.
In connect_server(), if we failed to add the connection to the session,
only destroy the conn_stream if we just allocated it, otherwise it may
have been allocated outside connect_server(), along with a connection which
has its destination address set.
Also use si_release_endpoint() instead of cs_destroy(), to make sure the
stream_interface doesn't reference it anymore.
This should be backported to 1.9.
In case an asynchronous connection (ALPN) succeeds but the mux fails to
attach, we must release the stream interface's endpoint, otherwise we
leave the stream interface with an endpoint pointing to a freed connection
with si_ops == si_conn_ops, and sess_update_st_cer() calls si_shutw() on
it, causing it to crash.
This must be backported to 1.9 only.
In connect_server(), if the previous connection failed, but had an alpn, no
mux was created, and thus the stream_interface's endpoint would be the
connection. In this case, instead of forgetting about it, and overriding
the stream_interface's endpoint later, try to reuse the connection, or the
connection will still be in the session's connection list, and will reference
to a stream that was probably destroyed.
This should be backported to 1.9.
The code dealing with idle connections used to check the number of streams
available on the connection only to unlink the connection from the idle
list. But this still resulted in too many streams reusing the same connection
when they were already attached to it.
We must detect that there is no more room and refrain from using this
connection at all, and instead fall back to the no-reuse case. Ideally
we should try to search among other idle connections, but for a backport
let's stay safe.
This must be backported to 1.9.
The current test consists in removing muxes which report that they're going
to assign their last available stream, but a mux may already be saturated
without having passed in this situation at all. This is what happens with
mux_h2 when receiving a GOAWAY frame informing the mux about the ID of the
last stream the other end is willing to process. The limit suddenly changes
from near infinite to 0. Currently what happens is that such a mux remains
in the idle list for a long time and refuses all new streams. Now at least
it will only fail a single stream in a retryable way. A future improvement
should consist in trying to pick another connection from the idle list.
This fix must be backported to 1.9.
If an ALPN is set on the server line, then when we reach assign_tproxy_address,
the stream_interface's endpoint will be a connection, not a conn_stream,
so make sure assign_tproxy_address() handles both cases.
This should be backported to 1.9.
When an argument <draws> is present, it must be an integer value one
or greater, indicating the number of draws before selecting the least
loaded of these servers. It was indeed demonstrated that picking the
least loaded of two servers is enough to significantly improve the
fairness of the algorithm, by always avoiding to pick the most loaded
server within a farm and getting rid of any bias that could be induced
by the unfair distribution of the consistent list. Higher values N will
take away N-1 of the highest loaded servers at the expense of performance.
With very high values, the algorithm will converge towards the leastconn's
result but much slower. The default value is 2, which generally shows very
good distribution and performance. This algorithm is also known as the
Power of Two Random Choices and is described here :
http://www.eecs.harvard.edu/~michaelm/postscripts/handbook2001.pdf
The algo-specific settings move from the proxy to the LB algo this way :
- uri_whole => arg_opt1
- uri_len_limit => arg_opt2
- uri_dirs_depth1 => arg_opt3
These ones used to rely on separate variables called hh_name/hh_len
but they are exclusive with the former. Let's use the same variable
which becomes a generic argument name and length for the LB algorithm.
There are a few instances where the lookup algo is tested against
BE_LB_LKUP_CHTREE using a binary "AND" operation while this macro
is a value among a set, and not a bit. The test happens to work
because the value is exactly 4 and no bit overlaps with the other
possible values but this is a latent bug waiting for a new LB algo
to appear to strike. At the moment the only other algo sharing a bit
with it is the "first" algo which is never supported in the same code
places.
This fix should be backported to maintained versions for safety if it
passes easily, otherwise it's not important as it will not fix any
visible issue.
The "balance uri" options "whole", "len" and "depth" were not properly
inherited from the defaults sections. In addition, "whole" and "len"
were not even reset when parsing "uri", meaning that 2 subsequent
"balance uri" statements would not have the expected effect as the
options from the first one would remain for the second one.
This may be backported to all maintained versions.
In connect_server(), if we're using a new connection, and we have to
initialize the mux right away, only do it so after si_connect() has been
called. si_connect() is responsible for initializing the xprt, and the
mux initialization may depend on the xprt being usable, as it may try to
receive data. Otherwise, the connection will be flagged as having an error,
and we will have to try to connect a second time.
This should be backported to 1.9.
Instead of keeping track of the number of connections we're responsible for,
keep track of the number of connections we're responsible for that we are
currently considering idling (ie that we are not using, they may be in use
by other sessions), that way we can actually reuse connections when we have
more connections than the max configured.
When connecting to a server, and reusing a connection, always attempt to give
the owner of the previous session one of its own connections, so that one
session won't be responsible for too many connections.
This should be backported to 1.9.
When creating a new outgoing connection, if we're using ALPN and waiting
for the handshake completion to choose the mux, and for some reason the
handshake failed, add the SI_FL_ERR flag to the stream_interface, so that
process_streams() knows the connection failed, and can attempt to retry,
instead of just hanging.
This should be backported to 1.9.
When a session adds a connection to its connection list, we used to remove
connections for an another server if there were not enough room for our
server. This can't work, because those lists are now the list of connections
we're responsible for, not just the idle connections.
To fix this, allow for an unlimited number of servers, instead of using
an array, we're now using a linked list.
To access the first element of the list, correctly use LIST_ELEM(), or we
end up getting the head of the list, instead of getting the first connection.
This should be backported to 1.9.
In connect_server(), if we looked for an usable connection and failed to
find one, srv_conn won't be NULL at the end of list_for_each_entry(), but
will point to the head of a list, which is not a pointer to a struct
connection, so explicitely set it to NULL.
This should be backported to 1.9.
If, for some reason we failed to allocate a conn_stream when reusing an
existing connection, set srv_conn to NULL, so that we fail later, instead
of pretending all is right. This ends up giving a stream_interface with
no endpoint, and so the stream will never end.
This should be backported to 1.9.
In connect_server(), don't attempt to reuse the old connection if it's
targetting a different server than the one we're supposed to access, or
we will never be able to connect to a server if the first one we tried failed.
This should be backported to 1.9.
There was a reference to struct stream in conn_free() for the case
where we're freeing a connection that doesn't have a mux attached.
For now we know it's always a stream, and we only need to do it to
put a NULL in s->si[1].end.
Let's do it better by storing the pointer to si[1].end in the context
and specifying that this pointer is always nulled if the mux is null.
This way it allows a connection to detach itself from wherever it's
being used. Maybe we could even get rid of the condition on the mux.
We most often store the mux context there but it can also be something
else while setting up the connection. Better call it "ctx" and know
that it's the owner's context than misleadingly call it mux_ctx and
get caught doing suspicious tricks.
Add the newly created to the idle list as long as http-reuse != never, and
when completing a H2 request, add the connection to the safe list instead of
the idle list, if we have to add it at that point, that means we created
many streams so we know it's safe.
In session, don't keep an infinite number of connection that can idle.
Add a new frontend parameter, "max-session-srv-conns" to set a max number,
with a default value of 5.
Instead of trying to get the session from the connection, which is not
always there, and of course there could be multiple sessions per connection,
provide it with the init() and attach() methods, so that we know the
session for each outgoing stream.
Add a new command, "pool-max-conn" that sets the maximum number of connections
waiting in the orphan idling connections list (as activated with idle-timeout).
Using "-1" means unlimited. Using pools is now dependant on this.
PiBa-NL reported that since this commit f157384 ("MINOR: backend: count
the number of connect and reuse per server and per backend"), reg-test
connection/h00001 fails. Indeed it does, the server is not checked for
existing prior to updating its counter. It should also fail with
transparent mode.
Sadly we didn't have the cumulated number of connections established to
servers till now, so let's now update it per backend and per-server and
report it in the stats. On the stats page it appears in the tooltip
when hovering over the total sessions count field.
Add a new method to mux, "reset", that is used to let the mux know the
connection attempt failed, and we're about to retry, so it just have to
reinit itself. Currently only the H1 mux needs it.
CS_FL_EOS | CS_FL_REOS can be set by the mux if the connection failed, so make
sure we remove them before retrying to connect, or it may lead to a premature
close of the connection.
In connect_server(), don't attempt to reuse the conn_stream associated to
the stream_interface, if we already attempted a connection with it.
Using that conn_stream is only there for the cases where a connection and
a conn_stream was created ahead, mostly by http_proxy or by the LUA code.
If we already attempted to connect, that means we fail, and so we should
create a new connection.
No backport needed.
In connect_server(), if we already have a conn_stream, reuse it
instead of trying to create a new one. http_proxy and LUA both
manually create a conn_stream and a connection, and we want
to use it.
Add a new keyword for servers, "idle-timeout". If set, unused connections are
kept alive until the timeout happens, and will be picked for reuse if no
other connection is available.
http_proxy is special, because it creates its connection and conn_stream
earlier. So in assign_server(), check that the connection associated with
the conn_stream has a destination address set, and in connect_server(),
use the connection and the conn_stream already attached to the
stream_interface, instead of looking for a connection in the session, and
creating a new conn_stream.
Instead of parsing all the available connections owned by the session
each time we choose a server, even if prefer-last-server is not set,
just do it if prefer-last-server is used, and check if the server is usable,
before checking the connections.
Instead of just storing the last connection in the session, store all of
the connections, for at most MAX_SRV_LIST (currently 5) targets.
That way we can do keepalive on more than 1 outgoing connection when the
client uses HTTP/2.
When creating a new outgoing H2 connection, put it in the idle list so that
it's immediately available for others to use, if http-reuse always is used.
When we're deferring the mux choice until the ALPN is negociated, we
attach the connection to the stream_interface until it's done, so that we
can destroy it if something goes wrong and the stream is destroy.
Before calling si_attach_cs() to attach the conn_stream once we have it,
call si_detach_endpoint(), or is_attach_cs() would destroy the connection.
When we defer the mux choice until the ALPN is negociated, don't forget
to wake the stream once it's done, or it will never have the opportunity
to send data.
This switches explicit calls to various trivial registration methods for
keywords, muxes or protocols from constructors to INITCALL1 at stage
STG_REGISTER. All these calls have in common to consume a single pointer
and return void. Doing this removes 26 constructors. The following calls
were addressed :
- acl_register_keywords
- bind_register_keywords
- cfg_register_keywords
- cli_register_kw
- flt_register_keywords
- http_req_keywords_register
- http_res_keywords_register
- protocol_register
- register_mux_proto
- sample_register_convs
- sample_register_fetches
- srv_register_keywords
- tcp_req_conn_keywords_register
- tcp_req_cont_keywords_register
- tcp_req_sess_keywords_register
- tcp_res_cont_keywords_register
- flt_register_keywords
In commit c7566001 ("MINOR: server: Add "alpn" and "npn" keywords") and
commit 201b9f4e ("MAJOR: connections: Defer mux creation for outgoing
connection if alpn is set"), the build was broken on older OpenSSL
releases.
Move the #ifdef's around so that we build again with older OpenSSL
releases (0.9.8 was tested).
When we create a connection, if we have to defer the conn_stream and the
mux creation until we can decide it (ie until the SSL handshake is done, and
the ALPN is decided), store the connection in the stream_interface, so that
we're sure we can destroy it if needed.
The creation of the conn_stream for an outgoing connection has been delayed
a bit, and when using dispatch, a check was made to see if a conn_stream
was attached before the conn_stream was created, so remove the test, as
it's done later anyway, and create and install the conn_stream right away
when we don't have a server, as is done when we don't have an alpn/npn
defined.
If an ALPN (or a NPN) was chosen for a server, defer choosing the mux until
after the SSL handshake is done, and the ALPN/NPN has been negociated, so
that we know which mux to pick.
Do not destroy the connection when we're about to destroy a stream. This
prevents us from doing keepalive on server connections when the client is
using HTTP/2, as a new stream is created for each request.
Instead, the session is now responsible for destroying connections.
When reusing connections, the attach() mux method is now used to create a new
conn_stream.
Instead of trying to receive as soon as the connection is created, and to
eventually have to transfer subscription if we move connections, wait
until the connection is established before attempting to recv.
Commit 85b73e9 ("BUG/MEDIUM: stream: Make sure polling is right on retry.")
introduced a possible null dereference on the error path detected by gcc-7.
Let's simply assign srv_conn after checking the error and not before.
No backport is needed.
While "option prefer-last-server" only applies to non-deterministic load
balancing algorithms, 401/407 responses actually caused haproxy to prefer
the last server unconditionally.
As this breaks deterministic load balancing algorithms like uri, this
patch applies the same condition here.
Should be backported to 1.8 (together with "BUG/MINOR: only mark
connections private if NTLM is detected").
When retrying to connect to a server, because the previous connection failed,
make sure if we subscribed to the previous connection, the polling flags will
be true for the new fd.
No backport is needed.
The return value from conn_install_mux() was not checked, so if an
inconsistency happens in the code, or a memory allocation fails while
initializing the mux, we can crash while using an uninitialized mux.
In practice the code inconsistency does not really happen since we
cannot configure such a situation, except during development, but
the out of memory condition could definitely happen.
This should be backported to 1.8 (the code is a bit different there,
there are two calls to conn_install_mux()).
This adds the sample fetch 'be_conn_free([<backend>])'. This sample fetch
provides the total number of unused connections across available servers in the
specified backend.
To do so, mux choices are split to handle incoming and outgoing connections in a
different way. The protocol specified on the bind/server line is used in
priority. Then, for frontend connections, the ALPN is retrieved and used to
choose the best mux. For backend connection, there is no ALPN. Finaly, if no
protocol is specified and no protocol matches the ALPN, we fall back on a
default mux, choosing in priority the first mux with exactly the same mode.
The comment above the change remains true. We assume there is always 1
conn_stream per outgoing connectionq. Today, it is always true because H2 is not
supported yet for server connections.
It remained some fragments of the old buffers API in debug messages, here and
there.
This was caused by the recent buffer API changes, no backport is needed.
Chunks are only a subset of a buffer (a non-wrapping version with no head
offset). Despite this we still carry a lot of duplicated code between
buffers and chunks. Replacing chunks with buffers would significantly
reduce the maintenance efforts. This first patch renames the chunk's
fields to match the name and types used by struct buffers, with the goal
of isolating the code changes from the declaration changes.
Most of the changes were made with spatch using this coccinelle script :
@rule_d1@
typedef chunk;
struct chunk chunk;
@@
- chunk.str
+ chunk.area
@rule_d2@
typedef chunk;
struct chunk chunk;
@@
- chunk.len
+ chunk.data
@rule_i1@
typedef chunk;
struct chunk *chunk;
@@
- chunk->str
+ chunk->area
@rule_i2@
typedef chunk;
struct chunk *chunk;
@@
- chunk->len
+ chunk->data
Some minor updates to 3 http functions had to be performed to take size_t
ints instead of ints in order to match the unsigned length here.
Now the buffers only contain the header and a pointer to the storage
area which can be anywhere. This will significantly simplify buffer
swapping and will make it possible to map chunks on buffers as well.
The buf_empty variable was removed, as now it's enough to have size==0
and area==NULL to designate the empty buffer (thus a non-allocated head
is the empty buffer by default). buf_wanted for now is indicated by
size==0 and area==(void *)1.
The channels and the checks now embed the buffer's head, and the only
pointer is to the storage area. This slightly increases the unallocated
buffer size (3 extra ints for the empty buffer) but considerably
simplifies dynamic buffer management. It will also later permit to
detach unused checks.
The way the struct buffer is arranged has proven quite efficient on a
number of tests, which makes sense given that size is always accessed
and often first, followed by the othe ones.
These ones manipulate the output data count which will be specific to
the channel soon, so prepare the call points to use the channel only.
The b_* functions are now unused and were removed.
For large farms where servers are regularly added or removed, picking
a random server from the pool can ensure faster load transitions than
when using round-robin and less traffic surges on the newly added
servers than when using leastconn.
This commit introduces "balance random". It internally uses a random as
the key to the consistent hashing mechanism, thus all features available
in consistent hashing such as weights and bounded load via hash-balance-
factor are usable. It is extremely convenient because one common concern
when using random is what happens when a server is hammered a bit too
much. Here that can trivially be avoided, like in the configuration below :
backend bk0
balance random
hash-balance-factor 110
server-template s 1-100 127.0.0.1:8000 check inter 1s
Note that while "balance random" internally relies on a hash algorithm,
it holds the same properties as round-robin and as such is compatible with
reusing an existing server connection with "option prefer-last-server".
Commit 522eea7 ("MINOR: ssl: Handle sending early data to server.") added
a dependency on SRV_SSL_O_EARLY_DATA which only exists when USE_OPENSSL
is defined (which is probably not the best solution) and breaks the build
when ssl is not enabled. Just add an ifdef USE_OPENSSL around the block
for now.
This adds a new keyword on the "server" line, "allow-0rtt", if set, we'll try
to send early data to the server, as long as the client sent early data, as
in case the server rejects the early data, we no longer have them, and can't
resend them, so the only option we have is to send back a 425, and we need
to be sure the client knows how to interpret it correctly.
All the references to connections in the data path from streams and
stream_interfaces were changed to use conn_streams. Most functions named
"something_conn" were renamed to "something_cs" for this. Sometimes the
connection still is what matters (eg during a connection establishment)
and were not always renamed. The change is significant and minimal at the
same time, and was quite thoroughly tested now. As of this patch, all
accesses to the connection from upper layers go through the pass-through
mux.
For HTTP/2 and QUIC, we'll need to deal with multiplexed streams inside
a connection. After quite a long brainstorming, it appears that the
connection interface to the existing streams is appropriate just like
the connection interface to the lower layers. In fact we need to have
the mux layer in the middle of the connection, between the transport
and the data layer.
A mux can exist on two directions/sides. On the inbound direction, it
instanciates new streams from incoming connections, while on the outbound
direction it muxes streams into outgoing connections. The difference is
visible on the mux->init() call : in one case, an upper context is already
known (outgoing connection), and in the other case, the upper context is
not yet known (incoming connection) and will have to be allocated by the
mux. The session doesn't have to create the new streams anymore, as this
is performed by the mux itself.
This patch introduces this and creates a pass-through mux called
"mux_pt" which is used for all new connections and which only
calls the data layer's recv,send,wake() calls. One incoming stream
is immediately created when init() is called on the inbound direction.
There should not be any visible impact.
Note that the connection's mux is purposely not set until the session
is completed so that we don't accidently run with the wrong mux. This
must not cause any issue as the xprt_done_cb function is always called
prior to using mux's recv/send functions.
A lock for LB parameters has been added inside the proxy structure and atomic
operations have been used to update server variables releated to lb.
The only significant change is about lb_map. Because the servers status are
updated in the sync-point, we can call recalc_server_map function synchronously
in map_set_server_status_up/down function.
For now, we have a list of each type per thread. So there is no need to lock
them. This is the easiest solution for now, but not the best one because there
is no sharing between threads. An idle connection on a thread will not be able
be used by a stream on another thread. So it could be a good idea to rework this
patch later.
Now, each proxy contains a lock that must be used when necessary to protect
it. Moreover, all proxy's counters are now updated using atomic operations.
srv_queue([<backend>/]<server>) : integer
Returns an integer value corresponding to the number of connections currently
pending in the designated server's queue. If <backend> is omitted, then the
server is looked up in the current backend. It can sometimes be used together
with the "use-server" directive to force to use a known faster server when it
is not much loaded. See also the "srv_conn", "avg_queue" and "queue" sample
fetch methods.
The server state and weight was reworked to handle
"pending" values updated by checks/CLI/LUA/agent.
These values are commited to be propagated to the
LB stack.
In further dev related to multi-thread, the commit
will be handled into a sync point.
Pending values are named using the prefix 'next_'
Current values used by the LB stack are named 'cur_'
