upstream/haproxy
1
0
Fork 0
mirror of https://github.com/haproxy/haproxy.git synced 2026-04-12 04:16:14 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

BUG/MEDIUM: peers: don't fail twice to grab the update lock

Browse source 
When the expire task is running fast (i.e. running almost alone), it's
super hard to grab the update lock and peers can easily trigger the
watchdog because the time it takes to grab this lock is multiplied by
the number of updates to perform. This is easier to trigger at the end
of an injection session where the expire task is omni-present. Let's
just record that we failed once and don't fail a second time in the
loop.

This should be backported to 3.2, but probably not further given that
this area changed significantly in 3.2.
This commit is contained in:
Willy Tarreau 2025-09-03 11:54:45 +02:00
parent 324f0a60ab
commit 2421c3769a
1 changed files with 21 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
src/peers.c
View file

@ -1556,6 +1556,7 @@ static inline int peer_send_teachmsgs(struct appctx *appctx, struct peer *p,
{
int ret, new_pushed, use_timed;
int updates_sent = 0;
int failed_once = 0;
ret = 1;
use_timed = 0;
@ -1598,7 +1599,25 @@ static inline int peer_send_teachmsgs(struct appctx *appctx, struct peer *p,
HA_RWLOCK_RDUNLOCK(STK_TABLE_UPDT_LOCK, &st->table->updt_lock);
ret = peer_send_updatemsg(st, appctx, ts, updateid, new_pushed, use_timed);
HA_RWLOCK_RDLOCK(STK_TABLE_UPDT_LOCK, &st->table->updt_lock);
if (HA_RWLOCK_TRYRDLOCK(STK_TABLE_UPDT_LOCK, &st->table->updt_lock) != 0) {
if (failed_once) {
/* we've already faced contention twice in this
* loop, this is getting serious, do not insist
* anymore and come back later
*/
HA_ATOMIC_DEC(&ts->ref_cnt);
applet_have_more_data(appctx);
ret = -1;
goto out_unlocked;
}
/* OK contention happens, for this one we'll wait on the
* lock, but only once.
*/
failed_once++;
HA_RWLOCK_RDLOCK(STK_TABLE_UPDT_LOCK, &st->table->updt_lock);
}
HA_ATOMIC_DEC(&ts->ref_cnt);
if (ret <= 0)
break;
@ -1628,6 +1647,7 @@ static inline int peer_send_teachmsgs(struct appctx *appctx, struct peer *p,
out:
HA_RWLOCK_RDUNLOCK(STK_TABLE_UPDT_LOCK, &st->table->updt_lock);
out_unlocked:
return ret;
}