blob: dd5bb043ca23e6b3b5f7f00ea2b1c27224822059 [file] [log] [blame]
/*
* Queue management functions.
*
* Copyright 2000-2008 Willy Tarreau <w@1wt.eu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <common/config.h>
#include <common/memory.h>
#include <common/time.h>
#include <proto/queue.h>
#include <proto/server.h>
#include <proto/task.h>
struct pool_head *pool2_pendconn;
/* perform minimal intializations, report 0 in case of error, 1 if OK. */
int init_pendconn()
{
pool2_pendconn = create_pool("pendconn", sizeof(struct pendconn), MEM_F_SHARED);
return pool2_pendconn != NULL;
}
/* returns the effective dynamic maxconn for a server, considering the minconn
* and the proxy's usage relative to its dynamic connections limit. It is
* expected that 0 < s->minconn <= s->maxconn when this is called. If the
* server is currently warming up, the slowstart is also applied to the
* resulting value, which can be lower than minconn in this case, but never
* less than 1.
*/
unsigned int srv_dynamic_maxconn(const struct server *s)
{
unsigned int max;
if (s->proxy->beconn >= s->proxy->fullconn)
/* no fullconn or proxy is full */
max = s->maxconn;
else if (s->minconn == s->maxconn)
/* static limit */
max = s->maxconn;
else max = MAX(s->minconn,
s->proxy->beconn * s->maxconn / s->proxy->fullconn);
if ((s->state & SRV_WARMINGUP) &&
now.tv_sec < s->last_change + s->slowstart &&
now.tv_sec >= s->last_change) {
unsigned int ratio;
ratio = MAX(1, 100 * (now.tv_sec - s->last_change) / s->slowstart);
max = max * ratio / 100;
}
return max;
}
/*
* Manages a server's connection queue. This function will try to dequeue as
* many pending sessions as possible, and wake them up.
*/
void process_srv_queue(struct server *s)
{
struct proxy *p = s->proxy;
int maxconn;
/* First, check if we can handle some connections queued at the proxy. We
* will take as many as we can handle.
*/
maxconn = srv_dynamic_maxconn(s);
while (s->served < maxconn) {
struct session *sess = pendconn_get_next_sess(s, p);
if (sess == NULL)
break;
task_wakeup(sess->task, TASK_WOKEN_RES);
}
}
/* Detaches the next pending connection from either a server or a proxy, and
* returns its associated session. If no pending connection is found, NULL is
* returned. Note that neither <srv> nor <px> may be NULL.
* Priority is given to the oldest request in the queue if both <srv> and <px>
* have pending requests. This ensures that no request will be left unserved.
* The session is immediately marked as "assigned", and both its <srv> and
* <srv_conn> are set to <srv>,
*/
struct session *pendconn_get_next_sess(struct server *srv, struct proxy *px)
{
struct pendconn *ps, *pp;
struct session *sess;
ps = pendconn_from_srv(srv);
pp = pendconn_from_px(px);
/* we want to get the definitive pendconn in <ps> */
if (!pp) {
if (!ps)
return NULL;
} else {
/* pendconn exists in the proxy queue */
if (!ps || tv_islt(&pp->sess->logs.tv_request, &ps->sess->logs.tv_request)) {
ps = pp;
ps->sess->srv = srv;
}
}
sess = ps->sess;
pendconn_free(ps);
/* we want to note that the session has now been assigned a server */
sess->flags |= SN_ASSIGNED;
sess->srv = srv;
sess->srv_conn = srv;
srv->served++;
if (px->lbprm.server_take_conn)
px->lbprm.server_take_conn(srv);
return sess;
}
/* Adds the session <sess> to the pending connection list of server <sess>->srv
* or to the one of <sess>->proxy if srv is NULL. All counters and back pointers
* are updated accordingly. Returns NULL if no memory is available, otherwise the
* pendconn itself. If the session was already marked as served, its flag is
* cleared. It is illegal to call this function with a non-NULL sess->srv_conn.
*/
struct pendconn *pendconn_add(struct session *sess)
{
struct pendconn *p;
p = pool_alloc2(pool2_pendconn);
if (!p)
return NULL;
sess->pend_pos = p;
p->sess = sess;
p->srv = sess->srv;
if (sess->flags & SN_ASSIGNED && sess->srv) {
LIST_ADDQ(&sess->srv->pendconns, &p->list);
sess->srv->nbpend++;
sess->logs.srv_queue_size += sess->srv->nbpend;
if (sess->srv->nbpend > sess->srv->nbpend_max)
sess->srv->nbpend_max = sess->srv->nbpend;
} else {
LIST_ADDQ(&sess->be->pendconns, &p->list);
sess->be->nbpend++;
sess->logs.prx_queue_size += sess->be->nbpend;
if (sess->be->nbpend > sess->be->nbpend_max)
sess->be->nbpend_max = sess->be->nbpend;
}
sess->be->totpend++;
return p;
}
/*
* Detaches pending connection <p>, decreases the pending count, and frees
* the pending connection. The connection might have been queued to a specific
* server as well as to the proxy. The session also gets marked unqueued.
*/
void pendconn_free(struct pendconn *p)
{
LIST_DEL(&p->list);
p->sess->pend_pos = NULL;
if (p->srv)
p->srv->nbpend--;
else
p->sess->be->nbpend--;
p->sess->be->totpend--;
pool_free2(pool2_pendconn, p);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/