MEDIUM: session: don't apply the retry delay when redispatching

The retry delay is only useful when sticking to a same server. During
a redispatch, it's useless and counter-productive if we're sure to
switch to another server, which is almost guaranteed when there's
more than one server and the balancing algorithm is round robin, so
better not pass via the turn-around state in this case. It could be
done as well for leastconn, but there's a risk of always killing the
delay after the recovery of a server in a farm where it's almost
guaranteed to take most incoming traffic. So better only kill the
delay when using round robin.

diff --git a/src/session.c b/src/session.c
index 414ff65c69140d6dead1aaa939e44c85d0aa368d..0ef612dbb0565efcaade1f21ddf0dac8e814f17e 100644 (file)
--- a/src/session.c
+++ b/src/session.c
@@ -910,8 +910,13 @@ static int sess_update_st_cer(struct session *s, struct stream_interface *si)
                if (!si->err_type)
                        si->err_type = SI_ET_CONN_ERR;
 
-               si->state = SI_ST_TAR;
-               si->exp = tick_add(now_ms, MS_TO_TICKS(delay));
+               /* only wait when we're retrying on the same server */
+               if (si->state == SI_ST_ASS ||
+                   (s->be->lbprm.algo & BE_LB_KIND) != BE_LB_KIND_RR ||
+                   (s->be->srv_act <= 1)) {
+                       si->state = SI_ST_TAR;
+                       si->exp = tick_add(now_ms, MS_TO_TICKS(delay));
+               }
                return 0;
        }
        return 0;