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_'
2 places were using an open-coded implementation of this function to count
available servers. Note that the avg_queue_size() fetch didn't check that
the proxy was in STOPPED state so it would possibly return a wrong server
count here but that wouldn't impact the returned value.
Signed-off-by: Nenad Merdanovic <nmerdan@haproxy.com>
This is like the nbsrv() sample fetch function except that it works as
a converter so it can count the number of available servers of a backend
name retrieved using a sample fetch or an environment variable.
Signed-off-by: Nenad Merdanovic <nmerdan@haproxy.com>
Keeping the address and the port in the same field causes a lot of problems,
specifically on the DNS part where we're forced to cheat on the family to be
able to keep the port. This causes some issues such as some families not being
resolvable anymore.
This patch first moves the service port to a new field "svc_port" so that the
port field is never used anymore in the "addr" field (struct sockaddr_storage).
All call places were adapted (there aren't that many).
when using "option prefer-last-server", we may not always stay on
the same backend if option balance told us otherwise.
For example, backend may change in the following cases:
balance hdr()
balance rdp-cookie
balance source
balance uri
balance url_param
[wt: backport this to 1.7 and 1.6]
According to nbsrv() documentation this fetcher should return "an
integer value corresponding to the number of usable servers".
In case backend is disabled none of servers is usable, so I believe
fetcher should return 0.
This patch should be backported to 1.7, 1.6, 1.5.
Now we exclusively use xprt_get(XPRT_RAW) instead of &raw_sock or
xprt_get(XPRT_SSL) for &ssl_sock. This removes a bunch of #ifdef and
include spread over a number of location including backend, cfgparse,
checks, cli, hlua, log, server and session.
These 2 patches add ability to fetch frontend/backend name in your
logic, so they can be used later to make routing decisions (fe_name) or
taking some actions based on backend which responded to request (be_name).
In our case we needed a fetcher to be able to extract information we
needed from frontend name.
When a backend doesn't use any known LB algorithm, backend_lb_algo_str()
returns NULL. It used to cause "nil" to be printed in the stats dump
since version 1.4 but causes 1.7 to try to parse this NULL to encode
it as a CSV string, causing a crash on "show stat" in this case.
The only situation where this can happen is when "transparent" or
"dispatch" are used in a proxy, in which case the LB algorithm is
BE_LB_ALGO_NONE. Thus now we explicitly report "none" when this
situation is detected, and we preventively report "unknown" if any
unknown algorithm is detected, which may happen if such an algo is
added in the future and the function is not updated.
This fix must be backported to 1.7 and may be backported as far as
1.4, though it has less impact there.
We'll have to use srv_set_admin_flag() to propagate some server flags
during the startup, and we don't want the resulting actions to cause
warnings, logs nor e-mail alerts to be generated since we're just applying
the config or a state file. So let's condition these notifications to the
fact that we're starting.
For active servers, this is the sum of the eweights of all active
servers before this one in the backend, and
[srv->cumulative_weight .. srv_cumulative_weight + srv_eweight) is a
space occupied by this server in the range [0 .. lbprm.tot_wact), and
likewise for backup servers with tot_wbck. This allows choosing a
server or a range of servers proportional to their weight, by simple
integer comparison.
Signed-off-by: Andrew Rodland <andrewr@vimeo.com>
The "sni" server directive does some bad stuff on many occasions because
it works on a sample of type string and limits len to size-1 by hand. The
problem is that size used to be zero on many occasions before the recent
changes to smp_dup() and that it effectively results in setting len to -1
and writing the zero byte *before* the string (and not terminating the
string).
This patch makes use of the recently introduced smp_make_safe() to address
this issue.
This fix must be backported to 1.6.
Since commit 6879ad3 ("MEDIUM: sample: fill the struct sample with the
session, proxy and stream pointers") merged in 1.6-dev2, the sample
contains the pointer to the stream and sample fetch functions as well
as converters use it heavily.
The problem is that earlier commit 87b0966 ("REORG/MAJOR: session:
rename the "session" entity to "stream"") had split the session and
stream resulting in the possibility for smp->strm to be NULL before
the stream was initialized. This is what happens in tcp-request
connection rulesets, as discovered by Baptiste.
The sample fetch functions must now check that smp->strm is valid
before using it. An alternative could consist in using a dummy stream
with nothing in it to avoid some checks but it would only result in
deferring them to the next step anyway, and making it harder to detect
that a stream is valid or the dummy one.
There is still an issue with variables which requires a complete
independant fix. They use strm->sess to find the session with strm
possibly NULL and passed as an argument. All call places indirectly
use smp->strm to build strm. So the problem is there but the API needs
to be changed to remove this duplicate argument that makes it much
harder to know what pointer to use.
This fix must be backported to 1.6, as well as the next one fixing
variables.
There is a bug in connect_server() : we use si_attach_conn() to offer
the current session's connection to the session we're stealing the
connection from. Unfortunately, si_attach_conn() uses the standard data
connection operations while here we need to use the idle connection
operations.
This results in a situation where when the server's idle timeout strikes,
the read0 is silently ignored, causes the response channel to be shut down
for reads, and the connection remains attached. Next attempt to send a
request when using this connection simply results in nothing being done
because we try to send over an already closed connection. Worse, if the
client aborts, then no timeout remains at all and the session waits
forever and remains assigned to the server.
A more-or-less easy way to reproduce this bug is to have two concurrent
streams each connecting to a different server with "http-reuse aggressive",
typically a cache farm using a URL hash :
stream1: GET /1 HTTP/1.1
stream2: GET /2 HTTP/1.1
stream1: GET /2 HTTP/1.1
wait for the server 1's connection to timeout
stream2: GET /1 HTTP/1.1
The connection hangs here, and "show sess all" shows a closed connection
with a SHUTR on the response channel.
The fix is very simple though not optimal. It consists in calling
si_idle_conn() again after attaching the connection. But in practise
it should not be done like this. The real issue is that there's no way
to cleanly attach a connection to a stream interface without changing
the connection's operations. So the API clearly needs to be revisited
to make such operations easier.
Many thanks to Yves Lafon from W3C for providing lots of useful dumps
and testing patches to help figure the root cause!
This fix must be backported to 1.6.
This was the first transparent proxy technology supported by haproxy
circa 2005 but it was obsoleted in 2007 by Tproxy 4.0 which removed a
lot of the earlier versions' shortcomings and was finally merged into
the kernel. Since nobody has been using cttproxy for many years now
and nobody has even just tried to compile the files, it's time to
remove it. The doc was updated as well.
The union name "data" is a little bit heavy while we read the source
code because we can read "data.data.sint". The rename from "data" to "u"
makes the read easiest like "data.u.sint".
This patch remove the struct information stored both in the struct
sample_data and in the striuct sample. Now, only thestruct sample_data
contains data, and the struct sample use the struct sample_data for storing
his own data.
This strategy is less extreme than "always", it only dispatches first
requests to validated reused connections, and moves a connection from
the idle list to the safe list once it has seen a second request, thus
proving that it could be reused.
The "safe" mode consists in picking existing connections only when
processing a request that's not the first one from a connection. This
ensures that in case where the server finally times out and closes, the
client can decide to replay idempotent requests.
Now instead of closing the existing connection attached to the
stream interface, we first check if the one we pick was attached to
another stream interface, in which case the connections are swapped
if possible (eg: if the current connection is not private). That way
the previous connection remains attached to an existing session and
significantly increases the chances of being reused.
In connect_server(), if we don't have a connection attached to the
stream-int, we first look into the server's idle_conns list and we
pick the first one there, we detach it from its owner if it had one.
If we used to have a connection, we close it.
This mechanism works well but doesn't scale : as servers increase,
the likeliness that the connection attached to the stream interface
doesn't match the server and gets closed increases.
This flag is set on an outgoing connection when this connection gets
some properties that must not be shared with other connections, such
as dynamic transparent source binding, SNI or a proxy protocol header,
or an authentication challenge from the server. This will be needed
later to implement connection reuse.
Since we now always call this function with the reuse parameter cleared,
let's simplify the function's logic as it cannot return the existing
connection anymore. The savings on this inline function are appreciable
(240 bytes) :
$ size haproxy.old haproxy.new
text data bss dec hex filename
1020383 40816 36928 1098127 10c18f haproxy.old
1020143 40816 36928 1097887 10c09f haproxy.new
connect_server() already does most of the check that is done again in
si_alloc_conn(), so let's simply reuse the existing connection instead
of calling the function again. It will also simplify the connection
reuse.
Indeed, for reuse to be set, it also requires srv_conn to be valid. In the
end, the only situation where we have to release the existing connection
and allocate a new one is when reuse == 0.
objt_server() is called multiple times at various places while some
places already make use of srv for this. Let's move the call at the
top of the function and use it all over the place.
This patch removes the 32 bits unsigned integer and the 32 bit signed
integer. It replaces these types by a unique type 64 bit signed.
This makes easy the usage of integer and clarify signed and unsigned use.
With the previous version, signed and unsigned are used ones in place of
others, and sometimes the converter loose the sign. For example, divisions
are processed with "unsigned", if one entry is negative, the result is
wrong.
Note that the integer pattern matching and dotted version pattern matching
are already working with signed 64 bits integer values.
There is one user-visible change : the "uint()" and "sint()" sample fetch
functions which used to return a constant integer have been replaced with
a new more natural, unified "int()" function. These functions were only
introduced in the latest 1.6-dev2 so there's no impact on regular
deployments.
The new "sni" server directive takes a sample fetch expression and
uses its return value as a hostname sent as the TLS SNI extension.
A typical use case consists in forwarding the front connection's SNI
value to the server in a bridged HTTPS forwarder :
sni ssl_fc_sni
