[MEDIUM] redispatch queued sessions if possible when a server goes down.

diff --git a/haproxy.c b/haproxy.c
index a5c0035b431e0621b28697257ba25129ec4b5281..f7b5a8044813896a0a882c27f2191942e0ef40ad 100644 (file)
--- a/haproxy.c
+++ b/haproxy.c
@@ -5797,6 +5797,63 @@ int process_session(struct task *t) {
 }
 
 
+/* Sets server <s> down, notifies by all available means, recounts the
+ * remaining servers on the proxy and transfers queued sessions whenever
+ * possible to other servers.
+ */
+void set_server_down(struct server *s) {
+    struct pendconn *pc, *pc_bck, *pc_end;
+    struct session *sess;
+    int xferred;
+
+    s->state &= ~SRV_RUNNING;
+
+    if (s->health == s->rise) {
+       recount_servers(s->proxy);
+       recalc_server_map(s->proxy);
+
+       /* we might have sessions queued on this server and waiting for
+        * a connection. Those which are redispatchable will be queued
+        * to another server or to the proxy itself.
+        */
+       xferred = 0;
+       FOREACH_ITEM_SAFE(pc, pc_bck, &s->pendconns, pc_end, struct pendconn *, list) {
+           sess = pc->sess;
+           if ((sess->proxy->options & PR_O_REDISP)) {
+               /* The REDISP option was specified. We will ignore
+                * cookie and force to balance or use the dispatcher.
+                */
+               sess->flags &= ~(SN_DIRECT | SN_ASSIGNED | SN_ADDR_SET);
+               sess->srv = NULL; /* it's left to the dispatcher to choose a server */
+               if ((sess->flags & SN_CK_MASK) == SN_CK_VALID) {
+                   sess->flags &= ~SN_CK_MASK;
+                   sess->flags |= SN_CK_DOWN;
+               }
+               pendconn_free(pc);
+               task_wakeup(&rq, sess->task);
+               xferred++;
+           }
+       }
+
+       sprintf(trash, "%sServer %s/%s is DOWN. %d active and %d backup servers left.%s"
+               " %d sessions active, %d requeued, %d remaining in queue.\n",
+               s->state & SRV_BACKUP ? "Backup " : "",
+               s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
+               (s->proxy->srv_bck && !s->proxy->srv_act) ? " Running on backup." : "",
+               s->cur_sess, xferred, s->nbpend);
+
+       Warning(trash);
+       send_log(s->proxy, LOG_ALERT, trash);
+       
+       if (s->proxy->srv_bck == 0 && s->proxy->srv_act == 0) {
+           Alert("Proxy %s has no server available !\n", s->proxy->id);
+           send_log(s->proxy, LOG_EMERG, "Proxy %s has no server available !\n", s->proxy->id);
+       }
+    }
+    s->health = 0; /* failure */
+}
+
+
 
 /*
  * manages a server health-check. Returns
@@ -5900,28 +5957,8 @@ int process_chk(struct task *t) {
        /* here, we have seen a failure */
        if (s->health > s->rise)
            s->health--; /* still good */
-       else {
-           s->state &= ~SRV_RUNNING;
-           if (s->health == s->rise) {
-                recount_servers(s->proxy);
-               recalc_server_map(s->proxy);
-               Warning("%sServer %s/%s DOWN. %d active and %d backup servers left.%s\n",
-                        s->state & SRV_BACKUP ? "Backup " : "",
-                        s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
-                        (s->proxy->srv_bck && !s->proxy->srv_act) ? " Running on backup." : "");
-               send_log(s->proxy, LOG_ALERT,
-                         "%sServer %s/%s is DOWN. %d active and %d backup servers left.%s\n",
-                         s->state & SRV_BACKUP ? "Backup " : "",
-                         s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
-                         (s->proxy->srv_bck && !s->proxy->srv_act) ? " Running on backup." : "");
-
-               if (s->proxy->srv_bck == 0 && s->proxy->srv_act == 0) {
-                   Alert("Proxy %s has no server available !\n", s->proxy->id);
-                   send_log(s->proxy, LOG_EMERG, "Proxy %s has no server available !\n", s->proxy->id);
-               }
-           }
-           s->health = 0; /* failure */
-       }
+       else
+           set_server_down(s);
 
        //fprintf(stderr, "process_chk: 7\n");
        /* FIXME: we allow up to <inter> for a connection to establish, but we should use another parameter */
@@ -5966,30 +6003,8 @@ int process_chk(struct task *t) {
            /* failure or timeout detected */
            if (s->health > s->rise)
                s->health--; /* still good */
-           else {
-               s->state &= ~SRV_RUNNING;
-
-                if (s->health == s->rise) {
-                    recount_servers(s->proxy);
-                   recalc_server_map(s->proxy);
-                    Warning("%sServer %s/%s DOWN. %d active and %d backup servers left.%s\n",
-                            s->state & SRV_BACKUP ? "Backup " : "",
-                            s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
-                            (s->proxy->srv_bck && !s->proxy->srv_act) ? " Running on backup." : "");
-                    send_log(s->proxy, LOG_ALERT,
-                             "%sServer %s/%s is DOWN. %d active and %d backup servers left.%s\n",
-                             s->state & SRV_BACKUP ? "Backup " : "",
-                             s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
-                             (s->proxy->srv_bck && !s->proxy->srv_act) ? " Running on backup." : "");
-                    
-                    if (s->proxy->srv_bck == 0 && s->proxy->srv_act == 0) {
-                        Alert("Proxy %s has no server available !\n", s->proxy->id);
-                        send_log(s->proxy, LOG_EMERG, "Proxy %s has no server available !\n", s->proxy->id);
-                    }
-                }
-
-               s->health = 0; /* failure */
-           }
+           else
+               set_server_down(s);
            s->curfd = -1;
            //FD_CLR(fd, StaticWriteEvent);
            fd_delete(fd);