dovecot/config processes one more time - which are safe to kill?
Hello.
The problem with dovecot/config processes never ending and spawning new one on each reload (https://www.dovecot.org/list/dovecot/2016-November/106058.html) is becoming a problem here:
# ps aux|grep dovecot/config|wc -l 206
That's a lot of wasted memory - dovecot/config processes ate over 30GB of ram on 64GB box.
Before killing dovecot/config processes: # free -m total used free shared buff/cache available Mem: 64437 61656 483 0 2297
after:
# free -m total used free shared buff/cache available Mem: 64437 23676 37822 0 2939
Currently on dovecot 2.3.3. I guess it's very low priority to handle that, so: how can I figure out which dovecot/config processes are safe to be killed by external script?
Does "all beside 2 newest ones" rule look sane?
Thanks,
Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org )
In my Dovecot 2.2.32 I do not have such a problem.
czw., 13 gru 2018 o 10:18 Arkadiusz Miśkiewicz arekm@maven.pl napisał(a):
Hello.
The problem with dovecot/config processes never ending and spawning new one on each reload (https://www.dovecot.org/list/dovecot/2016-November/106058.html) is becoming a problem here:
# ps aux|grep dovecot/config|wc -l 206
That's a lot of wasted memory - dovecot/config processes ate over 30GB of ram on 64GB box.
Before killing dovecot/config processes: # free -m total used free shared buff/cache available Mem: 64437 61656 483 0 2297
after:
# free -m total used free shared buff/cache available Mem: 64437 23676 37822 0 2939
Currently on dovecot 2.3.3. I guess it's very low priority to handle that, so: how can I figure out which dovecot/config processes are safe to be killed by external script?
Does "all beside 2 newest ones" rule look sane?
Thanks,
Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org )
On 13/12/2018 17:02, j.emerlik wrote:
In my Dovecot 2.2.32 I do not have such a problem.
Most likely you don't use
shutdown_clients = no
option.
czw., 13 gru 2018 o 10:18 Arkadiusz Miśkiewicz
mailto:arekm@maven.pl> napisał(a): Hello. The problem with dovecot/config processes never ending and spawning new one on each reload (https://www.dovecot.org/list/dovecot/2016-November/106058.html) is becoming a problem here: # ps aux|grep dovecot/config|wc -l 206 That's a lot of wasted memory - dovecot/config processes ate over 30GB of ram on 64GB box. Before killing dovecot/config processes: # free -m total used free shared buff/cache available Mem: 64437 61656 483 0 2297 after: # free -m total used free shared buff/cache available Mem: 64437 23676 37822 0 2939 Currently on dovecot 2.3.3. I guess it's very low priority to handle that, so: how can I figure out which dovecot/config processes are safe to be killed by external script? Does "all beside 2 newest ones" rule look sane? Thanks, -- Arkadiusz Miśkiewicz, arekm / ( maven.pl <http://maven.pl> | pld-linux.org <http://pld-linux.org> )
-- Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org )
On 13/12/2018 10:18, Arkadiusz Miśkiewicz wrote:
Hello.
The problem with dovecot/config processes never ending and spawning new one on each reload (https://www.dovecot.org/list/dovecot/2016-November/106058.html) is becoming a problem here:
# ps aux|grep dovecot/config|wc -l 206
That's a lot of wasted memory - dovecot/config processes ate over 30GB of ram on 64GB box.
If anyone else uses shutdown_clients = no and has the same problem here is a script that needs to be run from cron and it kills old, unneeded config processes.
Works fine here.
-- Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org )
On 13 Dec 2018, at 11.18, Arkadiusz Miśkiewicz
Hello.
The problem with dovecot/config processes never ending and spawning new one on each reload (https://www.dovecot.org/list/dovecot/2016-November/106058.html) is becoming a problem here:
# ps aux|grep dovecot/config|wc -l 206
I think you also have 206 other Dovecot processes that are keeping the config process open? Maybe 206 imap-login processes or something? Anyway I'd expect that this would happen only if some other process is keeping a UNIX socket connection open to the config process. Unless of course there's some bug that just isn't shutting them down even though they don't have any connections.. But at least I couldn't easily reproduce that. I suppose there isn't much of a reason for existing processes to keep the config socket open after reload, so a patch like below would likely help. Although it probably should be delayed so that existing imap/pop3-login connections doing STARTTLS wouldn't fail if that causes a new config lookup. diff --git a/src/lib-master/master-service.c b/src/lib-master/master-service.c index 3de11fa1b..41005cb5e 100644 --- a/src/lib-master/master-service.c +++ b/src/lib-master/master-service.c @@ -815,6 +815,7 @@ void master_service_stop_new_connections(struct master_service *service) } if (service->login != NULL) master_login_stop(service->login); + master_service_close_config_fd(service); } bool master_service_is_killed(struct master_service *service)
That's a lot of wasted memory - dovecot/config processes ate over 30GB of ram on 64GB box.
Are you saying your config processes take 149 MB each? That doesn't sound right, unless you have a huge number of SSL certificates?
On 14/01/2019 01:43, Timo Sirainen wrote:
On 13 Dec 2018, at 11.18, Arkadiusz Miśkiewicz
wrote: Hello.
The problem with dovecot/config processes never ending and spawning new one on each reload (https://www.dovecot.org/list/dovecot/2016-November/106058.html) is becoming a problem here:
# ps aux|grep dovecot/config|wc -l 206
I think you also have 206 other Dovecot processes that are keeping the config process open? Maybe 206 imap-login processes or something? Anyway I'd expect that this would happen only if some other process is keeping a UNIX socket connection open to the config process. Unless of course there's some bug that just isn't shutting them down even though they don't have any connections.. But at least I couldn't easily reproduce that.
I suppose there isn't much of a reason for existing processes to keep the config socket open after reload, so a patch like below would likely help. Although it probably should be delayed so that existing imap/pop3-login connections doing STARTTLS wouldn't fail if that causes a new config lookup.
diff --git a/src/lib-master/master-service.c b/src/lib-master/master-service.c index 3de11fa1b..41005cb5e 100644 --- a/src/lib-master/master-service.c +++ b/src/lib-master/master-service.c @@ -815,6 +815,7 @@ void master_service_stop_new_connections(struct master_service *service) } if (service->login != NULL) master_login_stop(service->login); + master_service_close_config_fd(service); }
bool master_service_is_killed(struct master_service *service)
Wouldn't be it better if these other process simply reconnected to current config/stats/log processes? (I'm killing n-1 processes leaving youngest one alive) Hm, killing older "config" processes doesn't report that killed process was used by anything but likely this is logging behaviour difference only (between killing config/stats vs killing log (which reports thins like: Shutting down logging for 'imap-login: ' with 16 clients)) Mar 14 06:10:10 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 06:22:11 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 06:52:13 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 07:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=4825 uid=0 code=kill) Mar 14 07:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=4825 uid=0 code=kill) Mar 14 07:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=4825 uid=0 code=kill) Mar 14 07:10:15 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 07:16:16 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 08:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=20047 uid=0 code=kill) Mar 14 08:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=20047 uid=0 code=kill) Mar 14 08:28:21 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 08:32:17 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 08:44:16 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 08:56:17 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 09:01:04 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=31423 uid=0 code=kill) Mar 14 09:01:04 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=31423 uid=0 code=kill) Mar 14 09:01:04 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=31423 uid=0 code=kill) Mar 14 09:01:04 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=31423 uid=0 code=kill) Mar 14 11:00:22 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 11:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=31710 uid=0 code=kill) Mar 14 11:02:22 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 11:08:21 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 11:40:20 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 12:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=3995 uid=0 code=kill) Mar 14 12:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=3995 uid=0 code=kill) Mar 14 12:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=3995 uid=0 code=kill) Mar 14 12:06:19 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 12:16:21 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 12:36:20 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 12:52:17 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 13:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=7423 uid=0 code=kill) Mar 14 13:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=7423 uid=0 code=kill) Mar 14 13:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=7423 uid=0 code=kill) Mar 14 13:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=7423 uid=0 code=kill) Mar 14 13:58:18 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 14:01:03 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=13496 uid=0 code=kill) Mar 14 14:42:19 mailbox dovecot: master: Warning: SIGHUP received - reloading configuration Mar 14 15:01:02 mailbox dovecot: config: Warning: Killed with signal 15 (by pid=17043 uid=0 code=kill) Anyway the problem is not only with "config" processes. It is also with "stats": # ps aux|grep dovecot/stats | wc -l 71 and with with "log" processes: # ps aux|grep dovecot/log | wc -l 71 And only log processes report about being used by other processes when killed: Mar 14 15:37:41 mailbox dovecot: log(1828): Warning: Killed with signal 15 (by pid=2597 uid=0 code=kill) Mar 14 15:37:41 mailbox dovecot: log(1828): Warning: Shutting down logging for 'imap-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(1828): Warning: Shutting down logging for 'pop3-login: ' with 14 clients Mar 14 15:37:41 mailbox dovecot: log(1342): Warning: Killed with signal 15 (by pid=2597 uid=0 code=kill) Mar 14 15:37:41 mailbox dovecot: log(1342): Warning: Shutting down logging for 'imap-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(1342): Warning: Shutting down logging for 'pop3-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(13148): Warning: Killed with signal 15 (by pid=2597 uid=0 code=kill) Mar 14 15:37:41 mailbox dovecot: log(13148): Warning: Shutting down logging for 'imap-login: ' with 15 clients Mar 14 15:37:41 mailbox dovecot: log(13148): Warning: Shutting down logging for 'pop3-login: ' with 15 clients Mar 14 15:37:41 mailbox dovecot: log(31442): Warning: Killed with signal 15 (by pid=2597 uid=0 code=kill) Mar 14 15:37:41 mailbox dovecot: log(31442): Warning: Shutting down logging for 'imap-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(31442): Warning: Shutting down logging for 'imap: ' with 701 clients Mar 14 15:37:41 mailbox dovecot: log(31442): Warning: Shutting down logging for 'pop3-login: ' with 14 clients Mar 14 15:37:41 mailbox dovecot: log(30150): Warning: Killed with signal 15 (by pid=2597 uid=0 code=kill) Mar 14 15:37:41 mailbox dovecot: log(30150): Warning: Shutting down logging for 'imap-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(30150): Warning: Shutting down logging for 'imap: ' with 759 clients Mar 14 15:37:41 mailbox dovecot: log(30150): Warning: Shutting down logging for 'pop3-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(25422): Warning: Killed with signal 15 (by pid=2597 uid=0 code=kill) Mar 14 15:37:41 mailbox dovecot: log(25422): Warning: Shutting down logging for 'imap-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(25422): Warning: Shutting down logging for 'imap: ' with 849 clients Mar 14 15:37:41 mailbox dovecot: log(25422): Warning: Shutting down logging for 'pop3-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(8969): Warning: Killed with signal 15 (by pid=2597 uid=0 code=kill) Mar 14 15:37:41 mailbox dovecot: log(8969): Warning: Shutting down logging for 'imap-login: ' with 16 clients Mar 14 15:37:41 mailbox dovecot: log(8969): Warning: Shutting down logging for 'imap: ' with 802 clients Mar 14 15:37:41 mailbox dovecot: log(8969): Warning: Shutting down logging for 'pop3-login: ' with 16 clients Ok, so looks like my script should ask imap*, pop3* processes to be terminated, too (in some smart way probably like quite old connection - terminate, very fresh - don't touch. If all processes are gone then it would be safe to terminate log/stats/config). I'm reloading very often - SSL certs are very often changing here and there is no lazy loading in dovecot.
That's a lot of wasted memory - dovecot/config processes ate over 30GB of ram on 64GB box.
Are you saying your config processes take 149 MB each?
Yes.
That doesn't sound right, unless you have a huge number of SSL certificates?
Over 600 cert pairs at the moment and only that number because dovecot cannot handle much more. https://www.dovecot.org/list/dovecot/2016-October/105855.html https://dovecot.org/list/dovecot/2016-November/106083.html -- Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org )
participants (3)
-
Arkadiusz Miśkiewicz
-
j.emerlik
-
Timo Sirainen