* bug#32631: the Dovecot service stops working
@ 2018-09-04 10:27 Clément Lassieur
2018-09-06 9:11 ` Ludovic Courtès
` (2 more replies)
0 siblings, 3 replies; 9+ messages in thread
From: Clément Lassieur @ 2018-09-04 10:27 UTC (permalink / raw)
To: 32631
Hi,
Sometimes the Dovecot service stops working, which is difficult to
notice.
Then I have to
# herd restart dovecot
The only interesting thing I could find in the logs is:
Sep 4 11:47:12 mail2 dovecot: master: Warning: service(imap-login): process_limit (100) reached, client connections are being dropped
Clément
^ permalink raw reply [flat|nested] 9+ messages in thread* bug#32631: the Dovecot service stops working
2018-09-04 10:27 bug#32631: the Dovecot service stops working Clément Lassieur
@ 2018-09-06 9:11 ` Ludovic Courtès
2018-09-06 12:49 ` Clément Lassieur
2018-09-26 16:53 ` Clément Lassieur
2018-11-10 18:33 ` Clément Lassieur
2 siblings, 1 reply; 9+ messages in thread
From: Ludovic Courtès @ 2018-09-06 9:11 UTC (permalink / raw)
To: Clément Lassieur; +Cc: 32631
Hello,
Clément Lassieur <clement@lassieur.org> skribis:
> Sometimes the Dovecot service stops working, which is difficult to
> notice.
When it “stops working”, does the Shepherd service go down? Does “herd
status dovecot” shows that it was respawned? Is the dovecot process
still around?
Thanks,
Ludo’.
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#32631: the Dovecot service stops working
2018-09-06 9:11 ` Ludovic Courtès
@ 2018-09-06 12:49 ` Clément Lassieur
2018-09-06 20:31 ` Ludovic Courtès
0 siblings, 1 reply; 9+ messages in thread
From: Clément Lassieur @ 2018-09-06 12:49 UTC (permalink / raw)
To: Ludovic Courtès; +Cc: 32631
Ludovic Courtès <ludo@gnu.org> writes:
> Hello,
>
> Clément Lassieur <clement@lassieur.org> skribis:
>
>> Sometimes the Dovecot service stops working, which is difficult to
>> notice.
>
> When it “stops working”, does the Shepherd service go down? Does “herd
> status dovecot” shows that it was respawned? Is the dovecot process
> still around?
The dovecot process is still around, yes. I has happened several times
already (maybe 5), but I only recently identified it as a bug. I'll
investigate more when I encounter it again, but it's not easy to do
because I'm not the only user of the mail server.
I tagged it as serious because it affects my clients, and because it's
difficult to notice there's something wrong.
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#32631: the Dovecot service stops working
2018-09-06 12:49 ` Clément Lassieur
@ 2018-09-06 20:31 ` Ludovic Courtès
2018-09-06 21:05 ` Clément Lassieur
0 siblings, 1 reply; 9+ messages in thread
From: Ludovic Courtès @ 2018-09-06 20:31 UTC (permalink / raw)
To: Clément Lassieur; +Cc: 32631
Hi,
Clément Lassieur <clement@lassieur.org> skribis:
> Ludovic Courtès <ludo@gnu.org> writes:
>
>> Hello,
>>
>> Clément Lassieur <clement@lassieur.org> skribis:
>>
>>> Sometimes the Dovecot service stops working, which is difficult to
>>> notice.
>>
>> When it “stops working”, does the Shepherd service go down? Does “herd
>> status dovecot” shows that it was respawned? Is the dovecot process
>> still around?
>
> The dovecot process is still around, yes. I has happened several times
> already (maybe 5), but I only recently identified it as a bug. I'll
> investigate more when I encounter it again, but it's not easy to do
> because I'm not the only user of the mail server.
So it doesn’t look like a Shepherd issue, right?
Thanks,
Ludo’.
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#32631: the Dovecot service stops working
2018-09-06 20:31 ` Ludovic Courtès
@ 2018-09-06 21:05 ` Clément Lassieur
2018-09-07 12:10 ` Oleg Pykhalov
0 siblings, 1 reply; 9+ messages in thread
From: Clément Lassieur @ 2018-09-06 21:05 UTC (permalink / raw)
To: Ludovic Courtès; +Cc: 32631
Ludovic Courtès <ludo@gnu.org> writes:
> Hi,
>
> Clément Lassieur <clement@lassieur.org> skribis:
>
>> Ludovic Courtès <ludo@gnu.org> writes:
>>
>>> Hello,
>>>
>>> Clément Lassieur <clement@lassieur.org> skribis:
>>>
>>>> Sometimes the Dovecot service stops working, which is difficult to
>>>> notice.
>>>
>>> When it “stops working”, does the Shepherd service go down? Does “herd
>>> status dovecot” shows that it was respawned? Is the dovecot process
>>> still around?
>>
>> The dovecot process is still around, yes. I has happened several times
>> already (maybe 5), but I only recently identified it as a bug. I'll
>> investigate more when I encounter it again, but it's not easy to do
>> because I'm not the only user of the mail server.
>
> So it doesn’t look like a Shepherd issue, right?
No, it looks like a dovecot service issue :-)
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#32631: the Dovecot service stops working
2018-09-06 21:05 ` Clément Lassieur
@ 2018-09-07 12:10 ` Oleg Pykhalov
2018-09-07 12:58 ` Clément Lassieur
0 siblings, 1 reply; 9+ messages in thread
From: Oleg Pykhalov @ 2018-09-07 12:10 UTC (permalink / raw)
To: Clément Lassieur; +Cc: 32631
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Hello Clément,
Clément Lassieur <clement@lassieur.org> writes:
[…]
>>>>> Sometimes the Dovecot service stops working, which is difficult to
>>>>> notice.
>>>>
>>>> When it “stops working”, does the Shepherd service go down? Does “herd
>>>> status dovecot” shows that it was respawned? Is the dovecot process
>>>> still around?
>>>
>>> The dovecot process is still around, yes. I has happened several times
>>> already (maybe 5),
Do you mean the warning you posted before?
--8<---------------cut here---------------start------------->8---
Sep 4 11:47:12 mail2 dovecot: master: Warning: service(imap-login): process_limit (100) reached, client connections are being dropped
--8<---------------cut here---------------end--------------->8---
The ‘dovecot-configuration’ record has a ‘default-process-limit’ which
is setted to 100 by default. Could you try to increase it?
Also a ‘process_limit’ configuration string is described on Dovecot Wiki.
https://wiki.dovecot.org/LoginProcess
Thanks,
Oleg.
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^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#32631: the Dovecot service stops working
2018-09-07 12:10 ` Oleg Pykhalov
@ 2018-09-07 12:58 ` Clément Lassieur
0 siblings, 0 replies; 9+ messages in thread
From: Clément Lassieur @ 2018-09-07 12:58 UTC (permalink / raw)
To: Oleg Pykhalov; +Cc: 32631
Hi Oleg,
Oleg Pykhalov <go.wigust@gmail.com> writes:
> Hello Clément,
>
> Clément Lassieur <clement@lassieur.org> writes:
>
> […]
>
>>>>>> Sometimes the Dovecot service stops working, which is difficult to
>>>>>> notice.
>>>>>
>>>>> When it “stops working”, does the Shepherd service go down? Does “herd
>>>>> status dovecot” shows that it was respawned? Is the dovecot process
>>>>> still around?
>>>>
>>>> The dovecot process is still around, yes. I has happened several times
>>>> already (maybe 5),
>
> Do you mean the warning you posted before?
I meant that my dovecot process stopped working 5 times already.
> --8<---------------cut here---------------start------------->8---
> Sep 4 11:47:12 mail2 dovecot: master: Warning: service(imap-login): process_limit (100) reached, client connections are being dropped
> --8<---------------cut here---------------end--------------->8---
>
> The ‘dovecot-configuration’ record has a ‘default-process-limit’ which
> is setted to 100 by default. Could you try to increase it?
Well, I can, but that wouldn't fix the problem. Two dovecot clients
shouldn't consume 100 processes.
> Also a ‘process_limit’ configuration string is described on Dovecot Wiki.
>
> https://wiki.dovecot.org/LoginProcess
Thank you very much for that information, I'll have a look.
Clément
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#32631: the Dovecot service stops working
2018-09-04 10:27 bug#32631: the Dovecot service stops working Clément Lassieur
2018-09-06 9:11 ` Ludovic Courtès
@ 2018-09-26 16:53 ` Clément Lassieur
2018-11-10 18:33 ` Clément Lassieur
2 siblings, 0 replies; 9+ messages in thread
From: Clément Lassieur @ 2018-09-26 16:53 UTC (permalink / raw)
To: 32631
I just noticed
$ ps auxww | grep dovecot
dovenull 486 0.0 0.1 23708 5876 ? S Sep21 0:00 dovecot/imap-login
dovenull 596 0.0 0.1 23708 5752 ? S Sep25 0:00 dovecot/imap-login
dovenull 936 0.0 0.1 23708 5740 ? S Sep21 0:00 dovecot/imap-login
dovenull 1319 0.0 0.1 23708 5868 ? S Sep21 0:00 dovecot/imap-login
dovenull 1491 0.0 0.1 23708 5680 ? S Sep23 0:00 dovecot/imap-login
dovenull 1577 0.0 0.1 23708 5776 ? S Sep19 0:00 dovecot/imap-login
dovenull 2298 0.0 0.1 23708 5728 ? S Sep22 0:00 dovecot/imap-login
dovenull 2742 0.0 0.1 23708 5660 ? S Sep23 0:00 dovecot/imap-login
dovenull 2795 0.0 0.1 23708 5792 ? S Sep20 0:00 dovecot/imap-login
dovenull 3213 0.0 0.1 23708 5932 ? S Sep20 0:00 dovecot/imap-login
dovenull 4232 0.0 0.1 23708 5812 ? S Sep23 0:00 dovecot/imap-login
dovenull 4387 0.0 0.1 23708 5788 ? S Sep23 0:00 dovecot/imap-login
dovenull 4818 0.0 0.1 23708 5872 ? S Sep20 0:00 dovecot/imap-login
dovenull 6154 0.0 0.1 23708 5780 ? S Sep20 0:00 dovecot/imap-login
dovenull 6971 0.0 0.1 23708 5888 ? S Sep20 0:00 dovecot/imap-login
dovenull 7314 0.0 0.1 23708 5808 ? S Sep20 0:00 dovecot/imap-login
dovenull 7823 0.0 0.1 23708 5696 ? S Sep20 0:00 dovecot/imap-login
dovenull 8485 0.0 0.1 23708 5844 ? S Sep24 0:00 dovecot/imap-login
dovenull 8812 0.0 0.1 23708 5800 ? S Sep25 0:00 dovecot/imap-login
dovenull 8980 0.0 0.1 23708 5876 ? S Sep22 0:00 dovecot/imap-login
dovenull 9603 0.0 0.1 23708 5656 ? S Sep22 0:00 dovecot/imap-login
dovenull 10566 0.0 0.1 23708 5860 ? S Sep20 0:00 dovecot/imap-login
dovenull 10735 0.0 0.1 23708 5868 ? S Sep20 0:00 dovecot/imap-login
dovenull 11313 0.0 0.1 23708 5824 ? S Sep20 0:00 dovecot/imap-login
dovenull 11480 0.0 0.1 23708 5800 ? S Sep22 0:00 dovecot/imap-login
dovenull 11591 0.0 0.1 23708 5824 ? S Sep25 0:00 dovecot/imap-login
dovenull 12528 0.0 0.1 23708 5824 ? S Sep22 0:00 dovecot/imap-login
dovenull 13824 0.0 0.1 23708 5840 ? S Sep24 0:00 dovecot/imap-login
dovenull 14497 0.0 0.1 23708 5872 ? S Sep24 0:00 dovecot/imap-login
dovenull 14608 0.0 0.1 23708 5652 ? S Sep24 0:00 dovecot/imap-login
dovenull 15108 0.0 0.1 23708 5840 ? S Sep21 0:00 dovecot/imap-login
dovenull 15167 0.0 0.1 23708 5656 ? S Sep21 0:00 dovecot/imap-login
dovenull 15446 0.0 0.1 23708 5776 ? S Sep22 0:00 dovecot/imap-login
dovenull 15524 0.0 0.1 23708 5752 ? S Sep22 0:00 dovecot/imap-login
dovenull 20718 0.0 0.1 23708 5748 ? S 11:19 0:00 dovecot/imap-login
dovenull 20818 0.0 0.1 23708 5868 ? S Sep24 0:00 dovecot/imap-login
dovenull 21254 0.0 0.1 23708 5804 ? S Sep21 0:00 dovecot/imap-login
dovenull 23678 0.0 0.1 23708 5932 ? S 15:02 0:00 dovecot/imap-login
dovenull 24110 0.0 0.1 23708 5860 ? S Sep23 0:00 dovecot/imap-login
dovenull 24286 0.0 0.1 23708 5872 ? S Sep24 0:00 dovecot/imap-login
dovenull 24287 0.0 0.1 23708 5724 ? S Sep24 0:00 dovecot/imap-login
root 26297 0.0 0.0 14572 3180 ? Ss Sep19 0:05 /gnu/store/3sa5vslnqc7kvx2l6ngbdjl1np8kbwzn-dovecot-2.3.1/sbin/dovecot -F
dovecot 26298 0.0 0.0 12176 2568 ? S Sep19 0:02 dovecot/anvil
root 26299 0.0 0.0 12304 2796 ? S Sep19 0:02 dovecot/log
root 26300 0.0 0.1 17164 5712 ? S Sep19 0:08 dovecot/config
dovecot 26304 0.0 0.0 12288 2688 ? S Sep19 0:04 dovecot/stats
dovecot 27246 0.0 0.0 23152 3564 ? S 18:30 0:00 dovecot/auth
dovenull 27308 0.0 0.1 23708 5712 ? S 18:36 0:00 dovecot/imap-login
vmail 27309 0.0 0.1 16544 5216 ? S 18:36 0:00 dovecot/imap
dovenull 27322 0.0 0.1 23708 5828 ? S 18:36 0:00 dovecot/imap-login
vmail 27323 0.0 0.1 15820 4256 ? S 18:36 0:00 dovecot/imap
dovenull 27336 0.0 0.1 23708 5792 ? S Sep21 0:00 dovecot/imap-login
dovenull 27337 0.0 0.1 23708 5760 ? S Sep21 0:00 dovecot/imap-login
dovenull 27490 0.0 0.1 23708 5792 ? S Sep21 0:00 dovecot/imap-login
clement 27551 0.0 0.0 8260 1640 pts/0 S+ 18:52 0:00 grep dovecot
dovenull 27756 0.0 0.1 23708 5872 ? S Sep21 0:00 dovecot/imap-login
dovenull 28129 0.0 0.1 23708 5828 ? S Sep21 0:00 dovecot/imap-login
dovenull 28551 0.0 0.1 23708 5752 ? S Sep21 0:00 dovecot/imap-login
dovenull 28779 0.0 0.1 23708 5872 ? S Sep21 0:00 dovecot/imap-login
dovenull 29154 0.0 0.1 23708 5744 ? S Sep19 0:00 dovecot/imap-login
dovenull 29713 0.0 0.1 23708 5680 ? S Sep19 0:00 dovecot/imap-login
dovenull 29794 0.0 0.1 23708 5872 ? S Sep21 0:00 dovecot/imap-login
dovenull 31659 0.0 0.1 23708 5752 ? S Sep19 0:00 dovecot/imap-login
dovenull 32114 0.0 0.1 23708 5760 ? S Sep21 0:00 dovecot/imap-login
dovenull 32535 0.0 0.1 23708 5740 ? S Sep19 0:00 dovecot/imap-login
dovenull 32646 0.0 0.1 23708 5756 ? S Sep21 0:00 dovecot/imap-login
^ permalink raw reply [flat|nested] 9+ messages in thread
* bug#32631: the Dovecot service stops working
2018-09-04 10:27 bug#32631: the Dovecot service stops working Clément Lassieur
2018-09-06 9:11 ` Ludovic Courtès
2018-09-26 16:53 ` Clément Lassieur
@ 2018-11-10 18:33 ` Clément Lassieur
2 siblings, 0 replies; 9+ messages in thread
From: Clément Lassieur @ 2018-11-10 18:33 UTC (permalink / raw)
To: 32631-done
So, today I investigated a bit.
I found [1] and [2] interesting. I didn't do anything about [1], but I
enabled cache in my configuration.
Then I went to #dovecot@freenode and someone advised me to switch to
high-performance mode[6], which I did:
--8<---------------cut here---------------start------------->8---
<hidden> do you have same uid/gid for all users or do they each have their own?
<hidden> snape, if you have same uid/gid then set service_count = 0 for
imap-login, otherwise set it to 1 [13:45]
<hidden> and in latter scenario also set client_limit to 1 [13:46]
<snape> hidden: there is one vmail user [13:47]
<hidden> then you can set service_count = 0, process_limit = number of cores,
process_min_avail = same as process limit and client_limit to something
<snape> you mean, client_limit to 0? [13:53]
<hidden> total concurrency is process_limit * client_limit for tls connections
<hidden> non-tls connections are moved to imap process after logik
<hidden> login
<snape> ok so you suggest I switch to high-performance mode [13:54]
<hidden> yes
<snape> because it doesn't make sense to use high-security mode if all users
share the same uid/gid? [13:55]
<snape> i.e. if I use vmail?
<hidden> the important part here is that if you set client_limit to anything
above 1 the service_count needs to be 0
<hidden> yeah, in general we recommend high performance mode [13:56]
--8<---------------cut here---------------end--------------->8---
In order to do the switch I had to modify the service so that it accepts
the client-limit[3] and process-limit[4] options.
I also fixed[5] the default value of 'service-count' for the "auth"
service to 'unlimited', in case it matters.
At least, now I don't seem to have these ever-growing imap-login
processes anymore, so I'm closing this bug. I'll re-open it if it
happens again.
Cheers,
Clément
[1]: https://www.dovecot.org/list/dovecot/2011-December/080264.html
[2]: https://dovecot.org/pipermail/dovecot/2008-May/030813.html
[3]: https://git.savannah.gnu.org/cgit/guix.git/commit/?id=8d9bb4b4d05a20bef1cf7b1da2b1c5fb05f9b071
[4]: https://git.savannah.gnu.org/cgit/guix.git/commit/?id=be8dd4a5fec804f2f004dd3a87c2872af44dc88d
[5]: https://git.savannah.gnu.org/cgit/guix.git/commit/?id=a7553a7360ac07ff114b807fc3026f08158d34c8
[6]: https://wiki.dovecot.org/LoginProcess
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2018-11-10 18:34 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-04 10:27 bug#32631: the Dovecot service stops working Clément Lassieur
2018-09-06 9:11 ` Ludovic Courtès
2018-09-06 12:49 ` Clément Lassieur
2018-09-06 20:31 ` Ludovic Courtès
2018-09-06 21:05 ` Clément Lassieur
2018-09-07 12:10 ` Oleg Pykhalov
2018-09-07 12:58 ` Clément Lassieur
2018-09-26 16:53 ` Clément Lassieur
2018-11-10 18:33 ` Clément Lassieur
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