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haproxy/include/proto/queue.h

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[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
/*
BUG/MEDIUM: zero-weight servers must not dequeue requests from the backend It was reported that a server configured with a zero weight would sometimes still take connections from the backend queue. This issue is real, it happens this way : 1) the disabled server accepts a request with a cookie 2) many cookie-less requests accumulate in the backend queue 3) when the disabled server completes its request, it checks its own queue and the backend's queue 4) the server takes a pending request from the backend queue and processes it. In response, the server's cookie is assigned to the client, which ensures that some requests will continue to be served by this server, leading back to point 1 above. The fix consists in preventing a zero-weight server from dequeuing pending requests from the backend. Making use of srv_is_usable() in such tests makes the tests more robust against future changes. This fix must be backported to 1.4 and 1.3.
2012-01-20 14:57:05 +00:00
* include/proto/queue.h
* This file defines everything related to queues.
*
* Copyright (C) 2000-2012 Willy Tarreau - w@1wt.eu
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
#ifndef _PROTO_QUEUE_H
#define _PROTO_QUEUE_H
[CLEANUP] included common/version.h everywhere
2006-06-29 16:54:54 +00:00
#include <common/config.h>
[CLEANUP] renamed include/haproxy to include/common
2006-06-29 15:53:05 +00:00
#include <common/memory.h>
#include <common/mini-clist.h>
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
#include <types/proxy.h>
#include <types/queue.h>
#include <types/session.h>
#include <types/server.h>
#include <types/task.h>
BUG/MEDIUM: zero-weight servers must not dequeue requests from the backend It was reported that a server configured with a zero weight would sometimes still take connections from the backend queue. This issue is real, it happens this way : 1) the disabled server accepts a request with a cookie 2) many cookie-less requests accumulate in the backend queue 3) when the disabled server completes its request, it checks its own queue and the backend's queue 4) the server takes a pending request from the backend queue and processes it. In response, the server's cookie is assigned to the client, which ensures that some requests will continue to be served by this server, leading back to point 1 above. The fix consists in preventing a zero-weight server from dequeuing pending requests from the backend. Making use of srv_is_usable() in such tests makes the tests more robust against future changes. This fix must be backported to 1.4 and 1.3.
2012-01-20 14:57:05 +00:00
#include <proto/backend.h>
[MAJOR] ported pendconn to mempools v2 A pool_destroy() was also missing in deinit()
2007-05-13 18:19:55 +00:00
extern struct pool_head *pool2_pendconn;
int init_pendconn();
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
struct session *pendconn_get_next_sess(struct server *srv, struct proxy *px);
struct pendconn *pendconn_add(struct session *sess);
void pendconn_free(struct pendconn *p);
[BUG] fix the dequeuing logic to ensure that all requests get served The dequeuing logic was completely wrong. First, a task was assigned to all servers to process the queue, but this task was never scheduled and was only woken up on session free. Second, there was no reservation of server entries when a task was assigned a server. This means that as long as the task was not connected to the server, its presence was not accounted for. This was causing trouble when detecting whether or not a server had reached maxconn. Third, during a redispatch, a session could lose its place at the server's and get blocked because another session at the same moment would have stolen the entry. Fourth, the redispatch option did not work when maxqueue was reached for a server, and it was not possible to do so without indefinitely hanging a session. The root cause of all those problems was the lack of pre-reservation of connections at the server's, and the lack of tracking of servers during a redispatch. Everything relied on combinations of flags which could appear similarly in quite distinct situations. This patch is a major rework but there was no other solution, as the internal logic was deeply flawed. The resulting code is cleaner, more understandable, uses less magics and is overall more robust. As an added bonus, "option redispatch" now works when maxqueue has been reached on a server.
2008-06-20 13:04:11 +00:00
void process_srv_queue(struct server *s);
[CLEANUP] add a few "const char *" where appropriate As suggested by Markus Elfring, a few "const char *" have replaced some "char *" declarations where a function is not expected to modify a value. It does not change the code but it helps detecting coding errors.
2006-10-15 13:17:57 +00:00
unsigned int srv_dynamic_maxconn(const struct server *s);
REORG: checks: put the functions in the appropriate files ! Checks.c has become a total mess. A number of proxy or server maintenance and queue management functions were put there probably because they were used there, but that makes the code untouchable. And that's without saying that their names does not always relate to what they really do! So let's do a first pass by moving these ones : - set_backend_down() => backend.c - redistribute_pending() => queue.c:pendconn_redistribute() - check_for_pending() => queue.c:pendconn_grab_from_px() - shutdown_sessions => server.c:srv_shutdown_sessions() - shutdown_backup_sessions => server.c:srv_shutdown_backup_sessions() All of them were moved at once.
2014-05-16 09:48:10 +00:00
int pendconn_redistribute(struct server *s);
int pendconn_grab_from_px(struct server *s);
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
/* Returns the first pending connection for server <s>, which may be NULL if
* nothing is pending.
*/
[CLEANUP] add a few "const char *" where appropriate As suggested by Markus Elfring, a few "const char *" have replaced some "char *" declarations where a function is not expected to modify a value. It does not change the code but it helps detecting coding errors.
2006-10-15 13:17:57 +00:00
static inline struct pendconn *pendconn_from_srv(const struct server *s) {
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
if (!s->nbpend)
return NULL;
return LIST_ELEM(s->pendconns.n, struct pendconn *, list);
}
/* Returns the first pending connection for proxy <px>, which may be NULL if
* nothing is pending.
*/
[CLEANUP] add a few "const char *" where appropriate As suggested by Markus Elfring, a few "const char *" have replaced some "char *" declarations where a function is not expected to modify a value. It does not change the code but it helps detecting coding errors.
2006-10-15 13:17:57 +00:00
static inline struct pendconn *pendconn_from_px(const struct proxy *px) {
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
if (!px->nbpend)
return NULL;
return LIST_ELEM(px->pendconns.n, struct pendconn *, list);
}
MINOR: http: implement the max-keep-alive-queue setting 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.
2014-04-25 11:58:37 +00:00
/* Returns 0 if all slots are full on a server, or 1 if there are slots available. */
static inline int server_has_room(const struct server *s) {
return !s->maxconn || s->cur_sess < srv_dynamic_maxconn(s);
}
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
/* returns 0 if nothing has to be done for server <s> regarding queued connections,
[BUG] do not dequeue the backend's pending connections on a dead server Kai Krueger found that previous patch was incomplete, because there is an unconditionnal call to process_srv_queue() in session_free() which still causes a dead server to consume pending connections from the backend. This call was made unconditionnal so that we don't leave unserved connections in the server queue, for instance connections coming in with "option persist" which can bypass the server status check. However, the server must not touch the backend's queue if it is down. Another fear was that some connections might remain unserved when the server is using a dynamic maxconn if the number of connections to the backend is too low. Right now, srv_dynamic_maxconn() ensures this cannot happen, so the call can remain conditionnal. The fix consists in allowing a server to process it own queue whatever its state, but not to touch the backend's queue if it is down. Its queue should normally be empty when the server is down because it is redistributed when the server goes down. The only remaining cases are precisely the persistent connections with "option persist" set, coming in after the queue has been redispatched. Those ones must still be processed when a connection terminates. (cherry picked from commit cd485c44807bfcdb4928dd83c1907636b4e1b6f3)
2008-12-04 08:33:58 +00:00
* and non-zero otherwise. If the server is down, we only check its own queue. Suited
* for and if/else usage.
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
*/
[CLEANUP] add a few "const char *" where appropriate As suggested by Markus Elfring, a few "const char *" have replaced some "char *" declarations where a function is not expected to modify a value. It does not change the code but it helps detecting coding errors.
2006-10-15 13:17:57 +00:00
static inline int may_dequeue_tasks(const struct server *s, const struct proxy *p) {
MINOR: server: create srv_was_usable() from srv_is_usable() and use a pointer We used to call srv_is_usable() with either the current state and weights or the previous ones. This causes trouble for future changes, so let's first split it in two variants : - srv_is_usable(srv) considers the current status - srv_was_usable(srv) considers the previous status
2014-05-13 16:51:40 +00:00
return (s && (s->nbpend || (p->nbpend && srv_is_usable(s))) &&
[BUG] fix the dequeuing logic to ensure that all requests get served The dequeuing logic was completely wrong. First, a task was assigned to all servers to process the queue, but this task was never scheduled and was only woken up on session free. Second, there was no reservation of server entries when a task was assigned a server. This means that as long as the task was not connected to the server, its presence was not accounted for. This was causing trouble when detecting whether or not a server had reached maxconn. Third, during a redispatch, a session could lose its place at the server's and get blocked because another session at the same moment would have stolen the entry. Fourth, the redispatch option did not work when maxqueue was reached for a server, and it was not possible to do so without indefinitely hanging a session. The root cause of all those problems was the lack of pre-reservation of connections at the server's, and the lack of tracking of servers during a redispatch. Everything relied on combinations of flags which could appear similarly in quite distinct situations. This patch is a major rework but there was no other solution, as the internal logic was deeply flawed. The resulting code is cleaner, more understandable, uses less magics and is overall more robust. As an added bonus, "option redispatch" now works when maxqueue has been reached on a server.
2008-06-20 13:04:11 +00:00
(!s->maxconn || s->cur_sess < srv_dynamic_maxconn(s)));
[BIGMOVE] exploded the monolithic haproxy.c file into multiple files. The files are now stored under : - include/haproxy for the generic includes - include/types.h for the structures needed within prototypes - include/proto.h for function prototypes and inline functions - src/*.c for the C files Most include files are now covered by LGPL. A last move still needs to be done to put inline functions under GPL and not LGPL. Version has been set to 1.3.0 in the code but some control still needs to be done before releasing.
2006-06-26 00:48:02 +00:00
}
#endif /* _PROTO_QUEUE_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/