Now that we can't have duplicate proxies with similar capabilities, we
can remove some painful check. The first one is the check that made the
lookup function return NULL when a duplicate is found, as it prevented
it from being used in the config parser to detect duplicates.
First, findproxy() was renamed proxy_find_by_name() so that its explicit
that a name is required for the lookup. Second, we give this function
the ability to search for tables if needed. Third we now provide inline
wrappers to pass the appropriate PR_CAP_* flags and to explicitly look
up a frontend, backend or table.
It is sometimes desirable to wait for the body of an HTTP request before
taking a decision. This is what is being done by "balance url_param" for
example. The first use case is to buffer requests from slow clients before
connecting to the server. Another use case consists in taking the routing
decision based on the request body's contents. This option placed in a
frontend or backend forces the HTTP processing to wait until either the whole
body is received, or the request buffer is full, or the first chunk is
complete in case of chunked encoding. It can have undesired side effects with
some applications abusing HTTP by expecting unbufferred transmissions between
the frontend and the backend, so this should definitely not be used by
default.
Note that it would not work for the response because we don't reset the
message state before starting to forward. For the response we need to
1) reset the message state to MSG_100_SENT or BODY , and 2) to reset
body_len in case of chunked encoding to avoid counting it twice.
Now this one is dynamically allocated. It means that 280 bytes of memory
are saved per TCP stream, but more importantly that it will become
possible to remove the l7 pointer from fetches and converters since
it will be deduced from the stream and will support being null.
A lot of care was taken because it's easy to forget a test somewhere,
and the previous code used to always trust s->txn for being valid, but
all places seem to have been visited.
All HTTP fetch functions check the txn first so we shouldn't have any
issue there even when called from TCP. When branching from a TCP frontend
to an HTTP backend, the txn is properly allocated at the same time as the
hdr_idx.
Just like for the listener, the frontend is session-wide so let's move
it to the session. There are a lot of places which were changed but the
changes are minimal in fact.
With HTTP/2, we'll have to support multiplexed streams. A stream is in
fact the largest part of what we currently call a session, it has buffers,
logs, etc.
In order to catch any error, this commit removes any reference to the
struct session and tries to rename most "session" occurrences in function
names to "stream" and "sess" to "strm" when that's related to a session.
The files stream.{c,h} were added and session.{c,h} removed.
The session will be reintroduced later and a few parts of the stream
will progressively be moved overthere. It will more or less contain
only what we need in an embryonic session.
Sample fetch functions and converters will have to change a bit so
that they'll use an L5 (session) instead of what's currently called
"L4" which is in fact L6 for now.
Once all changes are completed, we should see approximately this :
L7 - http_txn
L6 - stream
L5 - session
L4 - connection | applet
There will be at most one http_txn per stream, and a same session will
possibly be referenced by multiple streams. A connection will point to
a session and to a stream. The session will hold all the information
we need to keep even when we don't yet have a stream.
Some more cleanup is needed because some code was already far from
being clean. The server queue management still refers to sessions at
many places while comments talk about connections. This will have to
be cleaned up once we have a server-side connection pool manager.
Stream flags "SN_*" still need to be renamed, it doesn't seem like
any of them will need to move to the session.
The channels were pointers to outside structs and this is not needed
anymore since the buffers have moved, but this complicates operations.
Move them back into the session so that both channels and stream interfaces
are always allocated for a session. Some places (some early sample fetch
functions) used to validate that a channel was NULL prior to dereferencing
it. Now instead we check if chn->buf is NULL and we force it to remain NULL
until the channel is initialized.
Commit 179085c ("MEDIUM: http: move Connection header processing earlier")
introduced a regression : the backend's HTTP mode is not considered anymore
when setting the session's HTTP mode, because wait_for_request() is only
called once, when the frontend receives the request (or when the frontend
is in TCP mode, when the backend receives the request).
The net effect is that in some situations when the frontend and the backend
do not work in the same mode (eg: keep-alive vs close), the backend's mode
is ignored.
This patch moves all that processing to a dedicated function, which is
called from the original place, as well as from session_set_backend()
when switching from an HTTP frontend to an HTTP backend in different
modes.
This fix must be backported to 1.5.
Twice in a week I found people were surprized by a "conditional timeout" not
being respected, because they add "if <cond>" after a timeout, and since
they don't see any error nor read the doc, the expect it to work. Let's
make the timeout parser reject extra arguments to avoid these situations.
Long-lived sessions are often subject to half-closed sessions resulting in
a lot of sessions appearing in FIN_WAIT state in the system tables, and no
way for haproxy to get rid of them. This typically happens because clients
suddenly disconnect without sending any packet (eg: FIN or RST was lost in
the path), and while the server detects this using an applicative heart
beat, haproxy does not close the connection.
This patch adds two new timeouts : "timeout client-fin" and
"timeout server-fin". The former allows one to override the client-facing
timeout when a FIN has been received or sent. The latter does the same for
server-facing connections, which is less useful.
A switch from a TCP frontend to an HTTP backend initializes the HTTP
transaction. txn->hdr_idx.size is used by hdr_idx_init() but not
necessarily initialized yet here, because the first call to hdr_idx_init()
is in fact placed in http_init_txn(). Moving it before the call is
enough to fix it. We also remove the useless extra confusing call
to hdr_idx_init().
The bug was introduced in 1.5-dev8 with commit ac1932d ("MEDIUM:
tune.http.maxhdr makes it possible to configure the maximum number
of HTTP headers"). No backport to stable is needed.
Finn Arne Gangstad suggested that we should have the ability to break
keep-alive when the target server has reached its maxconn and that a
number of connections are present in the queue. After some discussion
around his proposed patch, the following solution was suggested : have
a per-proxy setting to fix a limit to the number of queued connections
on a server after which we break keep-alive. This ensures that even in
high latency networks where keep-alive is beneficial, we try to find a
different server.
This patch is partially based on his original proposal and implements
this configurable threshold.
Large configurations can take time to parse when thousands of backends
are in use. Let's store all the proxies in trees.
findproxy_mode() has been modified to use the tree for lookups, which
has divided the parsing time by about 2.5. But many lookups are still
present at many places and need to be dealt with.
Currently, "balance url_param check_post" randomly works. If the client
sends chunked data and there's another chunk after the one containing the
data, http_request_forward_body() will advance msg->sov and move the start
of data to the beginning of the last chunk, and get_server_ph_post() will
not find the data.
In order to avoid this, we add an HTTP_MSGF_WAIT_CONN flag whose goal is
to prevent the forwarding code from parsing until the connection is
confirmed, so that we're certain not to fail on a redispatch. Note that
we need to force channel_auto_connect() since the output buffer is empty
and a previous analyser might have stopped auto-connect.
The flag is currently set whenever some L7 POST analysis is needed for a
connect() so that it correctly addresses all corner cases involving a
possible rewind of the buffer, waiting for a better fix.
Note that this has been broken for a very long time. Even all 1.4 versions
seem broken but differently, with ->sov pointing to the end of the arguments.
So the fix should be considered for backporting to all stable releases,
possibly including 1.3 which works differently.
When using some log-format directives in header insertion without HTTP mode,
the config parser used to report a cryptic message about option httplog being
downgraded to tcplog and with "(null):0" as the file name and line number.
This is because the lfs_file and lfs_line were not properly set for some valid
use cases of log-format directives. Now we cover http-request and http-response
as well.
This is a generic health check which can be used to match a
banner or send a request and analyse a server response.
It works in a send/expect ways and many exchange can be done between
HAProxy and a server to decide the server status, making HAProxy able to
speak the server's protocol.
It can send arbitrary regular or binary strings and match content as a
regular or binary string or a regex.
Signed-off-by: Baptiste Assmann <bedis9@gmail.com>
When a process with large stick tables is replaced by a new one and remains
present until the last connection finishes, it keeps these data in memory
for nothing since they will never be used anymore by incoming connections,
except during syncing with the new process. This is especially problematic
when dealing with long session protocols such as WebSocket as it becomes
possible to stack many processes and eat a lot of memory.
So the idea here is to know if a table still needs to be synced or not,
and to purge all unused entries once the sync is complete. This means that
after a few hundred milliseconds when everything has been synchronized with
the new process, only a few entries will remain allocated (only the ones
held by sessions during the restart) and all the remaining memory will be
freed.
Note that we carefully do that only after the grace period is expired so as
not to impact a possible proxy that needs to accept a few more connections
before leaving.
Doing this required to add a sync counter to the stick tables, to know how
many peer sync sessions are still in progress in order not to flush the entries
until all synchronizations are completed.
Benoit Dolez reported a failure to start haproxy 1.5-dev19. The
process would immediately report an internal error with missing
fetches from some crap instead of ACL names.
The cause is that some versions of gcc seem to trim static structs
containing a variable array when moving them to BSS, and only keep
the fixed size, which is just a list head for all ACL and sample
fetch keywords. This was confirmed at least with gcc 3.4.6. And we
can't move these structs to const because they contain a list element
which is needed to link all of them together during the parsing.
The bug indeed appeared with 1.5-dev19 because it's the first one
to have some empty ACL keyword lists.
One solution is to impose -fno-zero-initialized-in-bss to everyone
but this is not really nice. Another solution consists in ensuring
the struct is never empty so that it does not move there. The easy
solution consists in having a non-null list head since it's not yet
initialized.
A new "ILH" list head type was thus created for this purpose : create
an Initialized List Head so that gcc cannot move the struct to BSS.
This fixes the issue for this version of gcc and does not create any
burden for the declarations.
Some actions were clearly missing to process response headers. This
patch adds a new "http-response" ruleset which provides the following
actions :
- allow : stop evaluating http-response rules
- deny : stop and reject the response with a 502
- add-header : add a header in log-format mode
- set-header : set a header in log-format mode
Improve error log reporting in the format parser by always giving the
file name, line number, and directive name instead of the hard-coded
"log-format".
Previously we got this when dealing with log-format errors:
[WARNING] 101/183012 (8561) : Warning: log-format variable name 'r' is not suited to HTTP mode
[WARNING] 101/183012 (8561) : log-format: sample fetch <hdr(a,1)> may not be reliably used with 'log-format' because it needs 'HTTP request headers,HTTP response headers' which is not available here.
[WARNING] 101/183012 (8561) : Warning: no such variable name 'k' in log-format
Now we have this :
[WARNING] 101/183016 (8593) : parsing [fmt.cfg:8] : 'log-format' variable name 'r' is reserved for HTTP mode
[WARNING] 101/183016 (8593) : parsing [fmt.cfg:8] : 'log-format' : sample fetch <hdr(a,1)> may not be reliably used here because it needs 'HTTP request headers,HTTP response headers' which is not available here.
[WARNING] 101/183016 (8593) : parsing [fmt.cfg:15] : no such variable name 'k' in 'unique-id-format'
Commit a4312fa2 merged into dev18 improved log-format management by
processing "log-format" and "unique-id-format" where they were declared,
so that the faulty args could be reported with their correct line numbers.
Unfortunately, the log-format parser considers the proxy mode (TCP/HTTP)
and now if the directive is set before the "mode" statement, it can be
rejected and report warnings.
So we really need to parse these directives at the end of a section at
least. Right now we do not have an "end of section" event, so we need
to store the file name and line number for each of these directives,
and take care of them at the end.
One of the benefits is that now the line numbers can be inherited from
the line passing "option httplog" even if it's in a defaults section.
Future improvements should be performed to report line numbers in every
log-format processed by the parser.
While ACL args were resolved after all the config was parsed, it was not the
case with sample fetch args because they're almost everywhere now.
The issue is that ACLs now solely rely on sample fetches, so their args
resolving doesn't work anymore. And many fetches involving a server, a
proxy or a userlist don't work at all.
The real issue is that at the bottom layers we have no information about
proxies, line numbers, even ACLs in order to report understandable errors,
and that at the top layers we have no visibility over the locations where
fetches are referenced (think log node).
After failing multiple unsatisfying solutions attempts, we now have a new
concept of args list. The principle is that every proxy has a list head
which contains a number of indications such as the config keyword, the
context where it's used, the file and line number, etc... and a list of
arguments. This list head is of the same type as the elements, so it
serves as a template for adding new elements. This way, it is filled from
top to bottom by the callers with the information they have (eg: line
numbers, ACL name, ...) and the lower layers just have to duplicate it and
add an element when they face an argument they cannot resolve yet.
Then at the end of the configuration parsing, a loop passes over each
proxy's list and resolves all the args in sequence. And this way there is
all necessary information to report verbose errors.
The first immediate benefit is that for the first time we got very precise
location of issues (arg number in a keyword in its context, ...). Second,
in order to do this we had to parse log-format and unique-id-format a bit
earlier, so that was a great opportunity for doing so when the directives
are encountered (unless it's a default section). This way, the recorded
line numbers for these args are the ones of the place where the log format
is declared, not the end of the file.
Userlists report slightly more information now. They're the only remaining
ones in the ACL resolving function.
Proxy's acl_requires was a copy of all bits taken from ACLs, but we'll
get rid of ACL flags and only rely on sample fetches soon. The proxy's
acl_requires was only used to allocate an HTTP context when needed, and
was even forced in HTTP mode. So better have a flag which exactly says
what it's supposed to be used for.
The lookup was broken by commit 050536d5. The server ID is
initialized to a negative value but unfortunately not all the
tests were converted. Thanks to Igor at owind for reporting it.
Instead of storing a couple of (int, ptr) in the struct connection
and the struct session, we use a different method : we only store a
pointer to an integer which is stored inside the target object and
which contains a unique type identifier. That way, the pointer allows
us to retrieve the object type (by dereferencing it) and the object's
address (by computing the displacement in the target structure). The
NULL pointer always corresponds to OBJ_TYPE_NONE.
This reduces the size of the connection and session structs. It also
simplifies target assignment and compare.
In order to improve the generated code, we try to put the obj_type
element at the beginning of all the structs (listener, server, proxy,
si_applet), so that the original and target pointers are always equal.
A lot of code was touched by massive replaces, but the changes are not
that important.
Since recent changes on the global frontend, it was not possible anymore
to soft-reload a process which had a stats socket because the socket would
not be disabled upon reload. The only solution to this endless madness is
to have the global frontend part of normal proxies.
Since we don't want to get an ID that shifts all other proxies and causes
trouble in deployed environments, we assign it ID #0 which other proxies
can't grab, and we don't report it in the stats pages.
Herv Commowick reported an issue : haproxy dies in a segfault during a
soft restart if it tries to pause a disabled proxy. This is because disabled
proxies have no management task so we must not wake the task up. This could
easily remain unnoticed since the old process was expected to go away, so
having it go away faster was not really troubling. However, with sync peers,
it is obvious that there is no peer sync during this reload.
This issue has been introduced in 1.5-dev7 with the removal of the
maintain_proxies() function. No backport is needed.
Navigating through listeners was very inconvenient and error-prone. Not to
mention that listeners were linked in reverse order and reverted afterwards.
In order to definitely get rid of these issues, we now do the following :
- frontends have a dual-linked list of bind_conf
- frontends have a dual-linked list of listeners
- bind_conf have a dual-linked list of listeners
- listeners have a pointer to their bind_conf
This way we can now navigate from anywhere to anywhere and always find the
proper bind_conf for a given listener, as well as find the list of listeners
for a current bind_conf.
Some settings need to be merged per-bind config line and are not necessarily
SSL-specific. It becomes quite inconvenient to have this ssl_conf SSL-specific,
so let's replace it with something more generic.
SSL config holds many parameters which are per bind line and not per
listener. Let's use a per-bind line config instead of having it
replicated for each listener.
At the moment we only do this for the SSL part but this should probably
evolved to handle more of the configuration and maybe even the state per
bind line.
Get rid of these confusing BF_* flags. Now channel naming should clearly
be used everywhere appropriate.
No code was changed, only a renaming was performed. The comments about
channel operations was updated.
Option httplog needs to be checked only once the proxy has been validated,
so that its final mode (tcp/http) can be used. Also we need to check for
httplog before checking the log format, so that we can report a warning
about this specific option and not about the format it implies.
Tunnel timeouts are used when TCP connections are forwarded, or
when forwarding upgraded HTTP connections (WebSocket) as well as
CONNECT requests to proxies.
This timeout allows long-lived sessions to be supported without
having to set large timeouts to normal requests.
All keywords registered using a cfg_kw_list now make use of the new error reporting
framework. This allows easier and more precise error reporting without having to
deal with complex buffer allocation issues.
The Unique ID, is an ID generated with several informations. You can use
a log-format string to customize it, with the "unique-id-format" keyword,
and insert it in the request header, with the "unique-id-header" keyword.
Sometimes it is desirable to forward a particular request to a specific
server without having to declare a dedicated backend for this server. This
can be achieved using the "use-server" rules. These rules are evaluated after
the "redirect" rules and before evaluating cookies, and they have precedence
on them. There may be as many "use-server" rules as desired. All of these
rules are evaluated in their declaration order, and the first one which
matches will assign the server.
parse_logformat_string: parse the string, detect the type: text,
separator or variable
parse_logformat_var: dectect variable name
parse_logformat_var_args: parse arguments and flags
add_to_logformat_list: add to the logformat linked list
This patch settles the 2 loggers limitation.
Loggers are now stored in linked lists.
Using "global log", the global loggers list content is added at the end
of the current proxy list. Each "log" entries are added at the end of
the proxy list.
"no log" flush a logger list.
For a long time, the max number of headers was taken as a part of the buffer
size. Since the header size can be configured at runtime, it does not make
much sense anymore.
Nothing was making it necessary to have a static value, so let's turn this into
a tunable with a default value of 101 which equals what was previously used.
It makes no sense to have one pointer to the hdr_idx pool in each proxy
struct since these pools do not depend on the proxy. Let's have a common
pool instead as it is already the case for other types.
Upon an incoming soft restart request, we first pause all frontends and
peers. If the caller changes its mind and asks us to resume (eg: failed
binding), we must resume all the frontends and peers. Unfortunately the
peers were not resumed.
The code was arranged to avoid code duplication (which used to hide the
issue till now).
Peers' frontends must have logging disabled by default, which was not
the case, so logs were randomly emitted upon restart, sometimes causing
a new process to fail to replace the old one.
This was revealed with one of the very latest patches which caused
the listener_queue not to be initialized on the stats socket frontend.
And in fact a number of other ones were missing too. This is getting so
boring that now we'll always make use of the same function to initialize
any proxy. Doing so has even saved about 500 bytes on the binary due to
the avoided code redundancy.
No backport is needed.
This function is finally not needed anymore, as it has been replaced with
a per-proxy task that is scheduled when some limits are encountered on
incoming connections or when the process is stopping. The savings should
be noticeable on configs with a large number of proxies. The most important
point is that the rate limiting is now enforced in a clean and solid way.
Peers were stopped on every call to maintain_proxies when stopping=1,
while they should only be stopped once upon call to soft_stop(). This
bug has little impact, mostly increased CPU usage. It's not needed to
backport it.
Patch d9bbe17b used to limit the rate-limit to off-by-one to avoid
a busy loop when the limit is reached. Now that the listeners are
automatically disabled and queued when a limit is reached, we don't
need this workaround anymore and can bring back the most accurate
computation.
Those states have been replaced with PR_STFULL and PR_STREADY respectively,
as it is what matches them the best now. Also, two occurrences of PR_STIDLE
in peers.c have been removed as this did not provide any form of error recovery
anyway.
Now maintain_proxies() only changes proxies states and does not affect their
listeners anymore since they are autonomous. A proxy will switch between the
PR_STIDLE and PR_STRUN states depending whether it's saturated or not. Next
step will consist in renaming PR_STIDLE to PR_STFULL. This state is now only
used to report the proxy state in the stats.
All listeners that are limited by a proxy-specific resource are now
queued at the proxy's and not globally. This allows finer-grained
wakeups when releasing resource.
Managing listeners state is difficult because they have their own state
and can at the same time have theirs dictated by their proxy. The pause
is not done properly, as the proxy code is fiddling with sockets. By
introducing new functions such as pause_listener()/resume_listener(), we
make it a bit more obvious how/when they're supposed to be used. The
listen_proxies() function was also renamed to resume_proxies() since
it's only used for pause/resume.
This patch is the first in a series aiming at getting rid of the maintain_proxies
mess. In the end, proxies should not call enable_listener()/disable_listener()
anymore.
There are some very rare server-to-server applications that abuse the HTTP
protocol and expect the payload phase to be highly interactive, with many
interleaved data chunks in both directions within a single request. This is
absolutely not supported by the HTTP specification and will not work across
most proxies or servers. When such applications attempt to do this through
haproxy, it works but they will experience high delays due to the network
optimizations which favor performance by instructing the system to wait for
enough data to be available in order to only send full packets. Typical
delays are around 200 ms per round trip. Note that this only happens with
abnormal uses. Normal uses such as CONNECT requests nor WebSockets are not
affected.
When "option http-no-delay" is present in either the frontend or the backend
used by a connection, all such optimizations will be disabled in order to
make the exchanges as fast as possible. Of course this offers no guarantee on
the functionality, as it may break at any other place. But if it works via
HAProxy, it will work as fast as possible. This option should never be used
by default, and should never be used at all unless such a buggy application
is discovered. The impact of using this option is an increase of bandwidth
usage and CPU usage, which may significantly lower performance in high
latency environments.
This change should be backported to 1.4 since the first report of such a
misuse was in 1.4. Next patch will also be needed.
It's very annoying that frontend and backend stats are merged because we
don't know what we're observing. For instance, if a "listen" instance
makes use of a distinct backend, it's impossible to know what the bytes_out
means.
Some points take care of not updating counters twice if the backend points
to the frontend, indicating a "listen" instance. The thing becomes more
complex when we try to add support for server side keep-alive, because we
have to maintain a pointer to the backend used for last request, and to
update its stats. But we can't perform such comparisons anymore because
the counters will not match anymore.
So in order to get rid of this situation, let's have both frontend AND
backend stats in the "struct proxy". We simply update the relevant ones
during activity. Some of them are only accounted for in the backend,
while others are just for frontend. Maybe we can improve a bit on that
later, but the essential part is that those counters now reflect what
they really mean.
This counter will help quickly spot whether there are new errors or not.
It is also assigned to each capture so that a script can keep trace of
which capture was taken when.
This counter is incremented for each incoming connection and each active
listener, and is used to prevent haproxy from stopping upon SIGUSR1. It
will thus be possible for some tasks in increment this counter in order
to prevent haproxy from dying until they have completed their job.
Signal zero is never delivered by the system. However having a signal to
which functions and tasks can subscribe to be notified of a stopping event
is useful. So this patch does two things :
1) allow signal zero to be delivered from any function of signal handler
2) make soft_stop() deliver this signal so that tasks can be notified of
a stopping condition.
The conn_retries attribute is now assigned when switching from SI_ST_INI
to SI_ST_REQ. This eliminates one of the last dependencies on the backend
in the frontend's accept() function.
The conn_retries still lies in the session and its initialization depends
on the backend when it may not yet be known. Let's first move it to the
stream interface.
It was particularly embarrassing that the server timeout was assigned
to buffers during an accept() just to be potentially changed later in
case of a use_backend rule. The frontend side has nothing to do with
server timeouts.
Now we initialize them right after the connect() succeeds. Later this
should change for a unique stream-interface timeout setting only.
The connection timeout stored in the buffer has not been used since the
stream interface were introduced. Let's get rid of it as it's one of the
things that complicate factoring of the accept() functions.
The 'client.c' file now only contained frontend-specific functions,
so it has naturally be renamed 'frontend.c'. Same for client.h. This
has also been an opportunity to remove some cross references from
files that should not have depended on it.
In the end, this file should contain a protocol-agnostic accept()
code, which would initialize a session, task, etc... based on an
accept() from a lower layer. Right now there are still references
to TCP.
The rate-limit feature relied on a timer to define how long a frontend
must remain idle. It was not considering the pending connections, so it
was almost always ready to be used again and only the accept's limit was
preventing new connections from coming in. By accounting for the pending
connection, we can compute a correct delay and effectively make the
frontend go idle for that (short) time.
Commit 4605e3b641cebbdbb2ee5726e5bbc3c03a2d7b5e was not enough, because
connections passing from a TCP frontend to an HTTP backend without any
ACL and via a "default_backend" statement were still working on non-initialized
data. An initialization was missing in the session_set_backend() function, next
to the initialization of hdr_idx.
It's sometimes convenient to know if a proxy has processed any connection
at all when stopping it. Since a soft restart causes the "Proxy stopped"
message to be logged for each proxy, let's add the number of connections
so that it's possible afterwards to check whether a proxy had received
any connection.
Gabriel Sosa reported that logs were appearing with BADREQ when
'option httplog' was used with a TCP proxy (eg: inherited via a
default instance). This patch detects it and falls back to tcplog
after emitting a warning.
(cherry picked from commit 5f0bd6537f)
Right now, an HTTP server cannot track a TCP server and vice-versa.
This patch enables proxy tracking without relying on the proxy's mode
(tcp/http/health). It only requires a matching proxy name to exist. The
original function was renamed to findproxy_mode().
Krzysztof reported that using names only for get weight/set weight
was not enough because it's still possible to have multiple servers
with the same name (and my test config is one of those). He suggested
to be able to designate them by their unique numeric IDs by prefixing
the ID with a dash.
That way we can have :
set weight #120/#2
as well as
get weight static/srv1 10
int get_backend_server(const char *bk_name, const char *sv_name,
struct proxy **bk, struct server **sv);
This function scans the list of backends and servers to retrieve the first
backend and the first server with the given names, and sets them in both
parameters. It returns zero if either is not found, or non-zero and sets
the ones it did not found to NULL. If a NULL pointer is passed for the
backend, only the pointer to the server will be updated.
Until now it was required that every custom ID was above 1000 in order to
avoid conflicts. Now we have the list of all assigned IDs and can automatically
pick the first unused one. This means that it is perfectly possible to interleave
automatic IDs with persistent IDs and the parser will automatically allocate
unused values starting with 1.
By default, when data is sent over a socket, both the write timeout and the
read timeout for that socket are refreshed, because we consider that there is
activity on that socket, and we have no other means of guessing if we should
receive data or not.
While this default behaviour is desirable for almost all applications, there
exists a situation where it is desirable to disable it, and only refresh the
read timeout if there are incoming data. This happens on sessions with large
timeouts and low amounts of exchanged data such as telnet session. If the
server suddenly disappears, the output data accumulates in the system's
socket buffers, both timeouts are correctly refreshed, and there is no way
to know the server does not receive them, so we don't timeout. However, when
the underlying protocol always echoes sent data, it would be enough by itself
to detect the issue using the read timeout. Note that this problem does not
happen with more verbose protocols because data won't accumulate long in the
socket buffers.
When this option is set on the frontend, it will disable read timeout updates
on data sent to the client. There probably is little use of this case. When
the option is set on the backend, it will disable read timeout updates on
data sent to the server. Doing so will typically break large HTTP posts from
slow lines, so use it with caution.
LB algo macros were composed of the LB algo by itself without any indication
of the method to use to look up a server (the lb function itself). This
method was implied by the LB algo, which was not very convenient to add
more algorithms. Now we have several fields in the LB macros, some to
describe what to look for in the requests, some to describe how to transform
that (kind of algo) and some to describe what lookup function to use.
The next patch will make it possible to factor out some code for all algos
which rely on a map.
Analyser bitmaps are now stored in the frontend and backend, and
combined at configuration time. That way, set_session_backend()
does not need to perform any protocol-specific combinations.
The new statement "persist rdp-cookie" enables RDP cookie
persistence. The RDP cookie is then extracted from the RDP
protocol, and compared against available servers. If a server
matches the RDP cookie, then it gets the connection.
Since we can now switch from TCP to HTTP, we need to be able to apply
the HTTP request timeout after switching. That means we need to take
it from the backend and not from the frontend. Since the backend points
to the frontend before switching, that changes nothing for the normal
case.
This patch allows a TCP frontend to switch to an HTTP backend.
During the switch, missing structures are automatically allocated.
The HTTP parser is enabled so that the backend first waits for a
full HTTP request.
The HTTP processing has been splitted into 7 steps, one of which
is not anymore HTTP-specific (content-switching). That way, it
becomes possible to use "use_backend" rules in TCP mode. A new
"use_server" directive should follow soon.
This is a first step towards support of multiple configuration files.
Now readcfgfile() only reads a file in memory and performs very minimal
parsing. The checks are performed afterwards.
Some users want to keep the max sessions/s seen on servers, frontends
and backends for capacity planning. It's easy to grab it while the
session count is updated, so let's keep it.
