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Willy Tarreaubaaee002006-06-26 02:48:02 +02001/*
2 * Queue management functions.
3 *
Willy Tarreauac68c5d2009-10-04 23:12:44 +02004 * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
Willy Tarreaubaaee002006-06-26 02:48:02 +02005 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 */
12
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020013/* Short explanation on the locking, which is far from being trivial : a
14 * pendconn is a list element which necessarily is associated with an existing
15 * stream. It has pendconn->strm always valid. A pendconn may only be in one of
16 * these three states :
17 * - unlinked : in this case it is an empty list head ;
18 * - linked into the server's queue ;
19 * - linked into the proxy's queue.
20 *
21 * A stream does not necessarily have such a pendconn. Thus the pendconn is
22 * designated by the stream->pend_pos pointer. This results in some properties :
23 * - pendconn->strm->pend_pos is never NULL for any valid pendconn
Patrick Hemmer0355dab2018-05-11 12:52:31 -040024 * - if p->node.node.leaf_p is NULL, the element is unlinked,
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020025 * otherwise it necessarily belongs to one of the other lists ; this may
26 * not be atomically checked under threads though ;
27 * - pendconn->px is never NULL if pendconn->list is not empty
Willy Tarreau88930dd2018-07-26 07:38:54 +020028 * - pendconn->srv is never NULL if pendconn->list is in the server's queue,
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020029 * and is always NULL if pendconn->list is in the backend's queue or empty.
Willy Tarreau88930dd2018-07-26 07:38:54 +020030 * - pendconn->target is NULL while the element is queued, and points to the
31 * assigned server when the pendconn is picked.
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020032 *
33 * Threads complicate the design a little bit but rules remain simple :
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020034 * - the server's queue lock must be held at least when manipulating the
35 * server's queue, which is when adding a pendconn to the queue and when
36 * removing a pendconn from the queue. It protects the queue's integrity.
37 *
38 * - the proxy's queue lock must be held at least when manipulating the
39 * proxy's queue, which is when adding a pendconn to the queue and when
40 * removing a pendconn from the queue. It protects the queue's integrity.
41 *
Willy Tarreau3201e4e2018-07-26 08:23:24 +020042 * - both locks are compatible and may be held at the same time.
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020043 *
44 * - a pendconn_add() is only performed by the stream which will own the
45 * pendconn ; the pendconn is allocated at this moment and returned ; it is
46 * added to either the server or the proxy's queue while holding this
Willy Tarreau3201e4e2018-07-26 08:23:24 +020047 * queue's lock.
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020048 *
49 * - the pendconn is then met by a thread walking over the proxy or server's
50 * queue with the respective lock held. This lock is exclusive and the
51 * pendconn can only appear in one queue so by definition a single thread
52 * may find this pendconn at a time.
53 *
54 * - the pendconn is unlinked either by its own stream upon success/abort/
55 * free, or by another one offering it its server slot. This is achieved by
56 * pendconn_process_next_strm() under either the server or proxy's lock,
57 * pendconn_redistribute() under the server's lock, pendconn_grab_from_px()
58 * under the proxy's lock, or pendconn_unlink() under either the proxy's or
59 * the server's lock depending on the queue the pendconn is attached to.
60 *
61 * - no single operation except the pendconn initialisation prior to the
Willy Tarreau3201e4e2018-07-26 08:23:24 +020062 * insertion are performed without eithre a queue lock held or the element
63 * being unlinked and visible exclusively to its stream.
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020064 *
Willy Tarreau88930dd2018-07-26 07:38:54 +020065 * - pendconn_grab_from_px() and pendconn_process_next_strm() assign ->target
66 * so that the stream knows what server to work with (via
67 * pendconn_dequeue() which sets it on strm->target).
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020068 *
69 * - a pendconn doesn't switch between queues, it stays where it is.
Willy Tarreau6bdd05c2018-07-25 15:21:00 +020070 */
71
Willy Tarreau4c7e4b72020-05-27 12:58:42 +020072#include <haproxy/api.h>
Willy Tarreauc761f842020-06-04 11:40:28 +020073#include <haproxy/http_rules.h>
Willy Tarreaud0ef4392020-06-02 09:38:52 +020074#include <haproxy/pool.h>
Willy Tarreaue6ce10b2020-06-04 15:33:47 +020075#include <haproxy/sample.h>
Willy Tarreau5e539c92020-06-04 20:45:39 +020076#include <haproxy/stream_interface.h>
Willy Tarreaucea0e1b2020-06-04 17:25:40 +020077#include <haproxy/task.h>
Willy Tarreau8b550af2020-06-04 17:42:48 +020078#include <haproxy/tcp_rules.h>
Willy Tarreau92b4f132020-06-01 11:05:15 +020079#include <haproxy/time.h>
Willy Tarreau3f567e42020-05-28 15:29:19 +020080#include <haproxy/thread.h>
Willy Tarreau8d2b7772020-05-27 10:58:19 +020081#include <import/eb32tree.h>
Willy Tarreaubaaee002006-06-26 02:48:02 +020082
Willy Tarreaubaaee002006-06-26 02:48:02 +020083#include <proto/queue.h>
84#include <proto/server.h>
Willy Tarreau87b09662015-04-03 00:22:06 +020085#include <proto/stream.h>
Willy Tarreaubaaee002006-06-26 02:48:02 +020086
87
Patrick Hemmer248cb4c2018-05-11 12:52:31 -040088#define NOW_OFFSET_BOUNDARY() ((now_ms - (TIMER_LOOK_BACK >> 12)) & 0xfffff)
89#define KEY_CLASS(key) ((u32)key & 0xfff00000)
90#define KEY_OFFSET(key) ((u32)key & 0x000fffff)
91#define KEY_CLASS_OFFSET_BOUNDARY(key) (KEY_CLASS(key) | NOW_OFFSET_BOUNDARY())
92#define MAKE_KEY(class, offset) (((u32)(class + 0x7ff) << 20) | ((u32)(now_ms + offset) & 0xfffff))
93
Willy Tarreau8ceae722018-11-26 11:58:30 +010094DECLARE_POOL(pool_head_pendconn, "pendconn", sizeof(struct pendconn));
Willy Tarreaubaaee002006-06-26 02:48:02 +020095
96/* returns the effective dynamic maxconn for a server, considering the minconn
Willy Tarreau86034312006-12-29 00:10:33 +010097 * and the proxy's usage relative to its dynamic connections limit. It is
Willy Tarreau9909fc12007-11-30 17:42:05 +010098 * expected that 0 < s->minconn <= s->maxconn when this is called. If the
99 * server is currently warming up, the slowstart is also applied to the
100 * resulting value, which can be lower than minconn in this case, but never
101 * less than 1.
Willy Tarreaubaaee002006-06-26 02:48:02 +0200102 */
Willy Tarreaub17916e2006-10-15 15:17:57 +0200103unsigned int srv_dynamic_maxconn(const struct server *s)
Willy Tarreaubaaee002006-06-26 02:48:02 +0200104{
Willy Tarreau9909fc12007-11-30 17:42:05 +0100105 unsigned int max;
106
Willy Tarreau86034312006-12-29 00:10:33 +0100107 if (s->proxy->beconn >= s->proxy->fullconn)
108 /* no fullconn or proxy is full */
Willy Tarreau9909fc12007-11-30 17:42:05 +0100109 max = s->maxconn;
110 else if (s->minconn == s->maxconn)
Willy Tarreau86034312006-12-29 00:10:33 +0100111 /* static limit */
Willy Tarreau9909fc12007-11-30 17:42:05 +0100112 max = s->maxconn;
113 else max = MAX(s->minconn,
114 s->proxy->beconn * s->maxconn / s->proxy->fullconn);
Willy Tarreau86034312006-12-29 00:10:33 +0100115
Emeric Brun52a91d32017-08-31 14:41:55 +0200116 if ((s->cur_state == SRV_ST_STARTING) &&
Willy Tarreau9909fc12007-11-30 17:42:05 +0100117 now.tv_sec < s->last_change + s->slowstart &&
118 now.tv_sec >= s->last_change) {
119 unsigned int ratio;
Willy Tarreau28a9e522008-09-14 17:43:27 +0200120 ratio = 100 * (now.tv_sec - s->last_change) / s->slowstart;
121 max = MAX(1, max * ratio / 100);
Willy Tarreau9909fc12007-11-30 17:42:05 +0100122 }
123 return max;
Willy Tarreaubaaee002006-06-26 02:48:02 +0200124}
125
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100126/* Remove the pendconn from the server/proxy queue. At this stage, the
127 * connection is not really dequeued. It will be done during the
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200128 * process_stream. It also decreases the pending count.
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100129 *
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200130 * The caller must own the lock on the queue containing the pendconn. The
131 * pendconn must still be queued.
Christopher Fauletf3a55db2017-06-09 14:26:38 +0200132 */
Willy Tarreau9624fae2018-07-25 08:04:20 +0200133static void __pendconn_unlink(struct pendconn *p)
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100134{
Patrick Hemmerda282f42018-05-11 12:52:31 -0400135 if (p->srv) {
136 p->strm->logs.srv_queue_pos += p->srv->queue_idx - p->queue_idx;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100137 p->srv->nbpend--;
Patrick Hemmerda282f42018-05-11 12:52:31 -0400138 } else {
139 p->strm->logs.prx_queue_pos += p->px->queue_idx - p->queue_idx;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100140 p->px->nbpend--;
Patrick Hemmerda282f42018-05-11 12:52:31 -0400141 }
Olivier Houchardb4df4922019-03-08 18:54:16 +0100142 _HA_ATOMIC_SUB(&p->px->totpend, 1);
Patrick Hemmer0355dab2018-05-11 12:52:31 -0400143 eb32_delete(&p->node);
Christopher Fauletf3a55db2017-06-09 14:26:38 +0200144}
145
Willy Tarreau7c6f8a22018-07-26 08:03:14 +0200146/* Locks the queue the pendconn element belongs to. This relies on both p->px
147 * and p->srv to be properly initialized (which is always the case once the
148 * element has been added).
149 */
150static inline void pendconn_queue_lock(struct pendconn *p)
151{
152 if (p->srv)
153 HA_SPIN_LOCK(SERVER_LOCK, &p->srv->lock);
154 else
155 HA_SPIN_LOCK(PROXY_LOCK, &p->px->lock);
156}
157
158/* Unlocks the queue the pendconn element belongs to. This relies on both p->px
159 * and p->srv to be properly initialized (which is always the case once the
160 * element has been added).
161 */
162static inline void pendconn_queue_unlock(struct pendconn *p)
163{
164 if (p->srv)
165 HA_SPIN_UNLOCK(SERVER_LOCK, &p->srv->lock);
166 else
167 HA_SPIN_UNLOCK(PROXY_LOCK, &p->px->lock);
168}
169
Willy Tarreau9624fae2018-07-25 08:04:20 +0200170/* Removes the pendconn from the server/proxy queue. At this stage, the
171 * connection is not really dequeued. It will be done during process_stream().
Willy Tarreau9ada0302019-11-14 14:58:39 +0100172 * This function takes all the required locks for the operation. The pendconn
173 * must be valid, though it doesn't matter if it was already unlinked. Prefer
174 * pendconn_cond_unlink() to first check <p>. When the locks are already held,
175 * please use __pendconn_unlink() instead.
Willy Tarreau9624fae2018-07-25 08:04:20 +0200176 */
177void pendconn_unlink(struct pendconn *p)
178{
Willy Tarreau7c6f8a22018-07-26 08:03:14 +0200179 pendconn_queue_lock(p);
Willy Tarreau9624fae2018-07-25 08:04:20 +0200180
Willy Tarreau9ada0302019-11-14 14:58:39 +0100181 if (p->node.node.leaf_p)
182 __pendconn_unlink(p);
Willy Tarreau9624fae2018-07-25 08:04:20 +0200183
Willy Tarreau7c6f8a22018-07-26 08:03:14 +0200184 pendconn_queue_unlock(p);
Willy Tarreau9624fae2018-07-25 08:04:20 +0200185}
186
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400187/* Retrieve the first pendconn from tree <pendconns>. Classes are always
188 * considered first, then the time offset. The time does wrap, so the
189 * lookup is performed twice, one to retrieve the first class and a second
190 * time to retrieve the earliest time in this class.
191 */
192static struct pendconn *pendconn_first(struct eb_root *pendconns)
193{
194 struct eb32_node *node, *node2 = NULL;
195 u32 key;
196
197 node = eb32_first(pendconns);
198 if (!node)
199 return NULL;
200
201 key = KEY_CLASS_OFFSET_BOUNDARY(node->key);
202 node2 = eb32_lookup_ge(pendconns, key);
203
204 if (!node2 ||
205 KEY_CLASS(node2->key) != KEY_CLASS(node->key)) {
206 /* no other key in the tree, or in this class */
207 return eb32_entry(node, struct pendconn, node);
208 }
209
210 /* found a better key */
211 return eb32_entry(node2, struct pendconn, node);
212}
213
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100214/* Process the next pending connection from either a server or a proxy, and
Christopher Fauletfd83f0b2018-03-19 15:22:09 +0100215 * returns a strictly positive value on success (see below). If no pending
216 * connection is found, 0 is returned. Note that neither <srv> nor <px> may be
217 * NULL. Priority is given to the oldest request in the queue if both <srv> and
218 * <px> have pending requests. This ensures that no request will be left
219 * unserved. The <px> queue is not considered if the server (or a tracked
220 * server) is not RUNNING, is disabled, or has a null weight (server going
221 * down). The <srv> queue is still considered in this case, because if some
222 * connections remain there, it means that some requests have been forced there
223 * after it was seen down (eg: due to option persist). The stream is
224 * immediately marked as "assigned", and both its <srv> and <srv_conn> are set
225 * to <srv>.
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100226 *
227 * This function must only be called if the server queue _AND_ the proxy queue
Christopher Fauletfd83f0b2018-03-19 15:22:09 +0100228 * are locked. Today it is only called by process_srv_queue. When a pending
229 * connection is dequeued, this function returns 1 if the pending connection can
230 * be handled by the current thread, else it returns 2.
Willy Tarreaubaaee002006-06-26 02:48:02 +0200231 */
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100232static int pendconn_process_next_strm(struct server *srv, struct proxy *px)
Willy Tarreaubaaee002006-06-26 02:48:02 +0200233{
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100234 struct pendconn *p = NULL;
Patrick Hemmerda282f42018-05-11 12:52:31 -0400235 struct pendconn *pp = NULL;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100236 struct server *rsrv;
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400237 u32 pkey, ppkey;
Willy Tarreaud132f742010-08-06 10:08:23 +0200238
Willy Tarreau44267702011-10-28 15:35:33 +0200239 rsrv = srv->track;
Willy Tarreaud132f742010-08-06 10:08:23 +0200240 if (!rsrv)
241 rsrv = srv;
Willy Tarreaubaaee002006-06-26 02:48:02 +0200242
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200243 p = NULL;
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400244 if (srv->nbpend)
245 p = pendconn_first(&srv->pendconns);
Willy Tarreau7c669d72008-06-20 15:04:11 +0200246
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400247 pp = NULL;
Willy Tarreaua8694652018-08-07 10:44:58 +0200248 if (srv_currently_usable(rsrv) && px->nbpend &&
249 (!(srv->flags & SRV_F_BACKUP) ||
250 (!px->srv_act &&
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400251 (srv == px->lbprm.fbck || (px->options & PR_O_USE_ALL_BK)))))
252 pp = pendconn_first(&px->pendconns);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100253
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400254 if (!p && !pp)
255 return 0;
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200256
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400257 if (p && !pp)
258 goto use_p;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100259
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400260 if (pp && !p)
261 goto use_pp;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100262
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400263 if (KEY_CLASS(p->node.key) < KEY_CLASS(pp->node.key))
264 goto use_p;
265
266 if (KEY_CLASS(pp->node.key) < KEY_CLASS(p->node.key))
267 goto use_pp;
268
269 pkey = KEY_OFFSET(p->node.key);
270 ppkey = KEY_OFFSET(pp->node.key);
271
272 if (pkey < NOW_OFFSET_BOUNDARY())
273 pkey += 0x100000; // key in the future
274
275 if (ppkey < NOW_OFFSET_BOUNDARY())
276 ppkey += 0x100000; // key in the future
277
278 if (pkey <= ppkey)
279 goto use_p;
280
281 use_pp:
282 /* Let's switch from the server pendconn to the proxy pendconn */
283 p = pp;
284 use_p:
Willy Tarreau9624fae2018-07-25 08:04:20 +0200285 __pendconn_unlink(p);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100286 p->strm_flags |= SF_ASSIGNED;
Willy Tarreau88930dd2018-07-26 07:38:54 +0200287 p->target = srv;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100288
Patrick Hemmerda282f42018-05-11 12:52:31 -0400289 if (p != pp)
290 srv->queue_idx++;
291 else
292 px->queue_idx++;
293
Olivier Houchardb4df4922019-03-08 18:54:16 +0100294 _HA_ATOMIC_ADD(&srv->served, 1);
295 _HA_ATOMIC_ADD(&srv->proxy->served, 1);
296 __ha_barrier_atomic_store();
Willy Tarreau7c669d72008-06-20 15:04:11 +0200297 if (px->lbprm.server_take_conn)
298 px->lbprm.server_take_conn(srv);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100299 __stream_add_srv_conn(p->strm, srv);
Willy Tarreau7c669d72008-06-20 15:04:11 +0200300
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100301 task_wakeup(p->strm->task, TASK_WOKEN_RES);
Christopher Fauletfd83f0b2018-03-19 15:22:09 +0100302
Olivier Houchardecfe6732018-07-26 18:47:27 +0200303 return 1;
Willy Tarreaubaaee002006-06-26 02:48:02 +0200304}
305
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100306/* Manages a server's connection queue. This function will try to dequeue as
Christopher Faulet87566c92017-06-06 10:34:51 +0200307 * many pending streams as possible, and wake them up.
308 */
309void process_srv_queue(struct server *s)
310{
311 struct proxy *p = s->proxy;
Olivier Houchardecfe6732018-07-26 18:47:27 +0200312 int maxconn;
Christopher Faulet87566c92017-06-06 10:34:51 +0200313
Christopher Faulet2a944ee2017-11-07 10:42:54 +0100314 HA_SPIN_LOCK(SERVER_LOCK, &s->lock);
Willy Tarreau5e83d992019-07-30 11:59:34 +0200315 HA_SPIN_LOCK(PROXY_LOCK, &p->lock);
Christopher Faulet87566c92017-06-06 10:34:51 +0200316 maxconn = srv_dynamic_maxconn(s);
317 while (s->served < maxconn) {
Christopher Fauletfd83f0b2018-03-19 15:22:09 +0100318 int ret = pendconn_process_next_strm(s, p);
319 if (!ret)
Christopher Faulet87566c92017-06-06 10:34:51 +0200320 break;
Christopher Faulet87566c92017-06-06 10:34:51 +0200321 }
Christopher Faulet2a944ee2017-11-07 10:42:54 +0100322 HA_SPIN_UNLOCK(PROXY_LOCK, &p->lock);
Willy Tarreau5e83d992019-07-30 11:59:34 +0200323 HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
Christopher Faulet87566c92017-06-06 10:34:51 +0200324}
325
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400326/* Adds the stream <strm> to the pending connection queue of server <strm>->srv
Willy Tarreau87b09662015-04-03 00:22:06 +0200327 * or to the one of <strm>->proxy if srv is NULL. All counters and back pointers
Willy Tarreaubaaee002006-06-26 02:48:02 +0200328 * are updated accordingly. Returns NULL if no memory is available, otherwise the
Willy Tarreau87b09662015-04-03 00:22:06 +0200329 * pendconn itself. If the stream was already marked as served, its flag is
330 * cleared. It is illegal to call this function with a non-NULL strm->srv_conn.
Patrick Hemmerda282f42018-05-11 12:52:31 -0400331 * The stream's queue position is counted with an offset of -1 because we want
332 * to make sure that being at the first position in the queue reports 1.
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100333 *
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400334 * The queue is sorted by the composition of the priority_class, and the current
335 * timestamp offset by strm->priority_offset. The timestamp is in milliseconds
336 * and truncated to 20 bits, so will wrap every 17m28s575ms.
337 * The offset can be positive or negative, and an offset of 0 puts it in the
338 * middle of this range (~ 8 min). Note that this also means if the adjusted
339 * timestamp wraps around, the request will be misinterpreted as being of
Joseph Herlantd8499ec2018-11-25 11:26:48 -0800340 * the highest priority for that priority class.
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400341 *
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100342 * This function must be called by the stream itself, so in the context of
343 * process_stream.
Willy Tarreaubaaee002006-06-26 02:48:02 +0200344 */
Willy Tarreau87b09662015-04-03 00:22:06 +0200345struct pendconn *pendconn_add(struct stream *strm)
Willy Tarreaubaaee002006-06-26 02:48:02 +0200346{
347 struct pendconn *p;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100348 struct proxy *px;
349 struct server *srv;
Willy Tarreaubaaee002006-06-26 02:48:02 +0200350
Willy Tarreaubafbe012017-11-24 17:34:44 +0100351 p = pool_alloc(pool_head_pendconn);
Willy Tarreaubaaee002006-06-26 02:48:02 +0200352 if (!p)
353 return NULL;
354
Willy Tarreau7c6f8a22018-07-26 08:03:14 +0200355 if (strm->flags & SF_ASSIGNED)
356 srv = objt_server(strm->target);
357 else
358 srv = NULL;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100359
Willy Tarreau7c6f8a22018-07-26 08:03:14 +0200360 px = strm->be;
Willy Tarreau88930dd2018-07-26 07:38:54 +0200361 p->target = NULL;
Willy Tarreau7c6f8a22018-07-26 08:03:14 +0200362 p->srv = srv;
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400363 p->node.key = MAKE_KEY(strm->priority_class, strm->priority_offset);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100364 p->px = px;
365 p->strm = strm;
366 p->strm_flags = strm->flags;
Willy Tarreau7c669d72008-06-20 15:04:11 +0200367
Willy Tarreau7c6f8a22018-07-26 08:03:14 +0200368 pendconn_queue_lock(p);
369
370 if (srv) {
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100371 srv->nbpend++;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100372 if (srv->nbpend > srv->counters.nbpend_max)
373 srv->counters.nbpend_max = srv->nbpend;
Patrick Hemmerda282f42018-05-11 12:52:31 -0400374 p->queue_idx = srv->queue_idx - 1; // for increment
Patrick Hemmer0355dab2018-05-11 12:52:31 -0400375 eb32_insert(&srv->pendconns, &p->node);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100376 }
377 else {
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100378 px->nbpend++;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100379 if (px->nbpend > px->be_counters.nbpend_max)
380 px->be_counters.nbpend_max = px->nbpend;
Patrick Hemmerda282f42018-05-11 12:52:31 -0400381 p->queue_idx = px->queue_idx - 1; // for increment
Patrick Hemmer0355dab2018-05-11 12:52:31 -0400382 eb32_insert(&px->pendconns, &p->node);
Willy Tarreaubaaee002006-06-26 02:48:02 +0200383 }
Willy Tarreau7c6f8a22018-07-26 08:03:14 +0200384 strm->pend_pos = p;
385
386 pendconn_queue_unlock(p);
387
Olivier Houchardb4df4922019-03-08 18:54:16 +0100388 _HA_ATOMIC_ADD(&px->totpend, 1);
Willy Tarreaubaaee002006-06-26 02:48:02 +0200389 return p;
390}
391
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200392/* Redistribute pending connections when a server goes down. The number of
Willy Tarreaudeca26c2018-08-21 18:11:03 +0200393 * connections redistributed is returned. It must be called with the server
394 * lock held.
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200395 */
396int pendconn_redistribute(struct server *s)
397{
Patrick Hemmer0355dab2018-05-11 12:52:31 -0400398 struct pendconn *p;
Willy Tarreaubff005a2019-05-27 08:10:11 +0200399 struct eb32_node *node, *nodeb;
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200400 int xferred = 0;
401
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100402 /* The REDISP option was specified. We will ignore cookie and force to
403 * balance or use the dispatcher. */
404 if ((s->proxy->options & (PR_O_REDISP|PR_O_PERSIST)) != PR_O_REDISP)
405 return 0;
406
Willy Tarreaubff005a2019-05-27 08:10:11 +0200407 for (node = eb32_first(&s->pendconns); node; node = nodeb) {
408 nodeb = eb32_next(node);
409
410 p = eb32_entry(node, struct pendconn, node);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100411 if (p->strm_flags & SF_FORCE_PRST)
412 continue;
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200413
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100414 /* it's left to the dispatcher to choose a server */
Willy Tarreau9624fae2018-07-25 08:04:20 +0200415 __pendconn_unlink(p);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100416 p->strm_flags &= ~(SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET);
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200417
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100418 task_wakeup(p->strm->task, TASK_WOKEN_RES);
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200419 }
420 return xferred;
421}
422
423/* Check for pending connections at the backend, and assign some of them to
424 * the server coming up. The server's weight is checked before being assigned
425 * connections it may not be able to handle. The total number of transferred
Willy Tarreau5e83d992019-07-30 11:59:34 +0200426 * connections is returned. It must be called with the server lock held, and
427 * will take the proxy's lock.
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200428 */
429int pendconn_grab_from_px(struct server *s)
430{
Patrick Hemmer0355dab2018-05-11 12:52:31 -0400431 struct pendconn *p;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100432 int maxconn, xferred = 0;
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200433
Emeric Brun52a91d32017-08-31 14:41:55 +0200434 if (!srv_currently_usable(s))
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200435 return 0;
436
Willy Tarreaua8694652018-08-07 10:44:58 +0200437 /* if this is a backup server and there are active servers or at
438 * least another backup server was elected, then this one must
439 * not dequeue requests from the proxy.
440 */
441 if ((s->flags & SRV_F_BACKUP) &&
442 (s->proxy->srv_act ||
443 ((s != s->proxy->lbprm.fbck) && !(s->proxy->options & PR_O_USE_ALL_BK))))
444 return 0;
445
Christopher Faulet2a944ee2017-11-07 10:42:54 +0100446 HA_SPIN_LOCK(PROXY_LOCK, &s->proxy->lock);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100447 maxconn = srv_dynamic_maxconn(s);
Patrick Hemmer248cb4c2018-05-11 12:52:31 -0400448 while ((p = pendconn_first(&s->proxy->pendconns))) {
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100449 if (s->maxconn && s->served + xferred >= maxconn)
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200450 break;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100451
Willy Tarreau9624fae2018-07-25 08:04:20 +0200452 __pendconn_unlink(p);
Willy Tarreau88930dd2018-07-26 07:38:54 +0200453 p->target = s;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100454
455 task_wakeup(p->strm->task, TASK_WOKEN_RES);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100456 xferred++;
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200457 }
Christopher Faulet2a944ee2017-11-07 10:42:54 +0100458 HA_SPIN_UNLOCK(PROXY_LOCK, &s->proxy->lock);
Willy Tarreau4aac7db2014-05-16 11:48:10 +0200459 return xferred;
460}
461
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100462/* Try to dequeue pending connection attached to the stream <strm>. It must
463 * always exists here. If the pendconn is still linked to the server or the
464 * proxy queue, nothing is done and the function returns 1. Otherwise,
465 * <strm>->flags and <strm>->target are updated, the pendconn is released and 0
466 * is returned.
467 *
468 * This function must be called by the stream itself, so in the context of
469 * process_stream.
Willy Tarreaubaaee002006-06-26 02:48:02 +0200470 */
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100471int pendconn_dequeue(struct stream *strm)
Willy Tarreaubaaee002006-06-26 02:48:02 +0200472{
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100473 struct pendconn *p;
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200474 int is_unlinked;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100475
476 if (unlikely(!strm->pend_pos)) {
477 /* unexpected case because it is called by the stream itself and
478 * only the stream can release a pendconn. So it is only
479 * possible if a pendconn is released by someone else or if the
480 * stream is supposed to be queued but without its associated
481 * pendconn. In both cases it is a bug! */
482 abort();
Christopher Faulet8ba59142017-06-27 15:43:53 +0200483 }
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100484 p = strm->pend_pos;
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200485
486 /* note below : we need to grab the queue's lock to check for emptiness
487 * because we don't want a partial _grab_from_px() or _redistribute()
488 * to be called in parallel and show an empty list without having the
489 * time to finish. With this we know that if we see the element
490 * unlinked, these functions were completely done.
491 */
492 pendconn_queue_lock(p);
Patrick Hemmer0355dab2018-05-11 12:52:31 -0400493 is_unlinked = !p->node.node.leaf_p;
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200494 pendconn_queue_unlock(p);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100495
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200496 if (!is_unlinked)
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100497 return 1;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100498
Willy Tarreau3201e4e2018-07-26 08:23:24 +0200499 /* the pendconn is not queued anymore and will not be so we're safe
500 * to proceed.
501 */
Willy Tarreau88930dd2018-07-26 07:38:54 +0200502 if (p->target)
503 strm->target = &p->target->obj_type;
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100504
505 strm->flags &= ~(SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET);
506 strm->flags |= p->strm_flags & (SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET);
507 strm->pend_pos = NULL;
Willy Tarreaubafbe012017-11-24 17:34:44 +0100508 pool_free(pool_head_pendconn, p);
Christopher Faulet5cd4bbd2018-03-14 16:18:06 +0100509 return 0;
Willy Tarreaubaaee002006-06-26 02:48:02 +0200510}
511
Patrick Hemmer268a7072018-05-11 12:52:31 -0400512static enum act_return action_set_priority_class(struct act_rule *rule, struct proxy *px,
513 struct session *sess, struct stream *s, int flags)
514{
515 struct sample *smp;
516
517 smp = sample_fetch_as_type(px, sess, s, SMP_OPT_DIR_REQ|SMP_OPT_FINAL, rule->arg.expr, SMP_T_SINT);
518 if (!smp)
519 return ACT_RET_CONT;
520
521 s->priority_class = queue_limit_class(smp->data.u.sint);
522 return ACT_RET_CONT;
523}
524
525static enum act_return action_set_priority_offset(struct act_rule *rule, struct proxy *px,
526 struct session *sess, struct stream *s, int flags)
527{
528 struct sample *smp;
529
530 smp = sample_fetch_as_type(px, sess, s, SMP_OPT_DIR_REQ|SMP_OPT_FINAL, rule->arg.expr, SMP_T_SINT);
531 if (!smp)
532 return ACT_RET_CONT;
533
534 s->priority_offset = queue_limit_offset(smp->data.u.sint);
535
536 return ACT_RET_CONT;
537}
538
539static enum act_parse_ret parse_set_priority_class(const char **args, int *arg, struct proxy *px,
540 struct act_rule *rule, char **err)
541{
542 unsigned int where = 0;
543
544 rule->arg.expr = sample_parse_expr((char **)args, arg, px->conf.args.file,
Willy Tarreaue3b57bf2020-02-14 16:50:14 +0100545 px->conf.args.line, err, &px->conf.args, NULL);
Patrick Hemmer268a7072018-05-11 12:52:31 -0400546 if (!rule->arg.expr)
547 return ACT_RET_PRS_ERR;
548
549 if (px->cap & PR_CAP_FE)
550 where |= SMP_VAL_FE_HRQ_HDR;
551 if (px->cap & PR_CAP_BE)
552 where |= SMP_VAL_BE_HRQ_HDR;
553
554 if (!(rule->arg.expr->fetch->val & where)) {
555 memprintf(err,
556 "fetch method '%s' extracts information from '%s', none of which is available here",
557 args[0], sample_src_names(rule->arg.expr->fetch->use));
558 free(rule->arg.expr);
559 return ACT_RET_PRS_ERR;
560 }
561
562 rule->action = ACT_CUSTOM;
563 rule->action_ptr = action_set_priority_class;
564 return ACT_RET_PRS_OK;
565}
566
567static enum act_parse_ret parse_set_priority_offset(const char **args, int *arg, struct proxy *px,
568 struct act_rule *rule, char **err)
569{
570 unsigned int where = 0;
571
572 rule->arg.expr = sample_parse_expr((char **)args, arg, px->conf.args.file,
Willy Tarreaue3b57bf2020-02-14 16:50:14 +0100573 px->conf.args.line, err, &px->conf.args, NULL);
Patrick Hemmer268a7072018-05-11 12:52:31 -0400574 if (!rule->arg.expr)
575 return ACT_RET_PRS_ERR;
576
577 if (px->cap & PR_CAP_FE)
578 where |= SMP_VAL_FE_HRQ_HDR;
579 if (px->cap & PR_CAP_BE)
580 where |= SMP_VAL_BE_HRQ_HDR;
581
582 if (!(rule->arg.expr->fetch->val & where)) {
583 memprintf(err,
584 "fetch method '%s' extracts information from '%s', none of which is available here",
585 args[0], sample_src_names(rule->arg.expr->fetch->use));
586 free(rule->arg.expr);
587 return ACT_RET_PRS_ERR;
588 }
589
590 rule->action = ACT_CUSTOM;
591 rule->action_ptr = action_set_priority_offset;
592 return ACT_RET_PRS_OK;
593}
594
595static struct action_kw_list tcp_cont_kws = {ILH, {
596 { "set-priority-class", parse_set_priority_class },
597 { "set-priority-offset", parse_set_priority_offset },
598 { /* END */ }
599}};
600
Willy Tarreau0108d902018-11-25 19:14:37 +0100601INITCALL1(STG_REGISTER, tcp_req_cont_keywords_register, &tcp_cont_kws);
602
Patrick Hemmer268a7072018-05-11 12:52:31 -0400603static struct action_kw_list http_req_kws = {ILH, {
604 { "set-priority-class", parse_set_priority_class },
605 { "set-priority-offset", parse_set_priority_offset },
606 { /* END */ }
607}};
608
Willy Tarreau0108d902018-11-25 19:14:37 +0100609INITCALL1(STG_REGISTER, http_req_keywords_register, &http_req_kws);
610
Patrick Hemmer268a7072018-05-11 12:52:31 -0400611static int
612smp_fetch_priority_class(const struct arg *args, struct sample *smp, const char *kw, void *private)
613{
614 if (!smp->strm)
615 return 0;
616
617 smp->data.type = SMP_T_SINT;
618 smp->data.u.sint = smp->strm->priority_class;
619
620 return 1;
621}
622
623static int
624smp_fetch_priority_offset(const struct arg *args, struct sample *smp, const char *kw, void *private)
625{
626 if (!smp->strm)
627 return 0;
628
629 smp->data.type = SMP_T_SINT;
630 smp->data.u.sint = smp->strm->priority_offset;
631
632 return 1;
633}
634
635
636static struct sample_fetch_kw_list smp_kws = {ILH, {
637 { "prio_class", smp_fetch_priority_class, 0, NULL, SMP_T_SINT, SMP_USE_INTRN, },
638 { "prio_offset", smp_fetch_priority_offset, 0, NULL, SMP_T_SINT, SMP_USE_INTRN, },
639 { /* END */},
640}};
641
Willy Tarreau0108d902018-11-25 19:14:37 +0100642INITCALL1(STG_REGISTER, sample_register_fetches, &smp_kws);
Patrick Hemmer268a7072018-05-11 12:52:31 -0400643
Willy Tarreaubaaee002006-06-26 02:48:02 +0200644/*
645 * Local variables:
646 * c-indent-level: 8
647 * c-basic-offset: 8
648 * End:
649 */