Hi.
I've noticed that dovecot (using 2.2.26.0 here) starts dovecot/config processes that stay for long time. Example:
[root@ixion-pld ~]# service dovecot restart Stopping Dovecot service.......................................................................................................................................[ DONE ] Starting Dovecot service.......................................................................................................................................[ DONE ] [root@ixion-pld ~]# ps aux|grep dovecot root 25333 0.0 0.0 13736 2480 ? Ss 09:40 0:00 /usr/sbin/dovecot dovecot 25336 0.0 0.0 9480 924 ? S 09:40 0:00 dovecot/anvil [0 connections] root 25337 0.0 0.0 9612 2416 ? S 09:40 0:00 dovecot/log root 25339 0.0 0.0 12496 3256 ? S 09:40 0:00 dovecot/config root 25341 0.0 0.0 132168 888 pts/1 S+ 09:40 0:00 grep dovecot [root@ixion-pld ~]# doveadm reload [root@ixion-pld ~]# ps aux|grep dovecot root 25333 0.0 0.0 13872 2720 ? Ss 09:40 0:00 /usr/sbin/dovecot dovecot 25336 0.0 0.0 9480 924 ? S 09:40 0:00 dovecot/anvil [0 connections] root 25344 0.0 0.0 9612 2428 ? S 09:40 0:00 dovecot/log root 25346 0.0 0.0 12496 3192 ? S 09:40 0:00 dovecot/config root 25348 0.0 0.0 132168 876 pts/1 S+ 09:40 0:00 grep dovecot
so far good - only one dovecot/config. Lets connect to pop3 and keep connection
[root@ixion-pld ~]# telnet localhost pop3 Trying 127.0.0.1.110... Connected to localhost. Escape character is '^]'. +OK Mail server ready.
on the other console
[root@ixion-pld ~]# ps aux|grep dovecot root 25333 0.0 0.0 13872 2720 ? Ss 09:40 0:00 /usr/sbin/dovecot dovecot 25336 0.0 0.0 9480 924 ? S 09:40 0:00 dovecot/anvil [2 connections] root 25344 0.0 0.0 9612 2428 ? S 09:40 0:00 dovecot/log root 25346 0.0 0.0 12496 3192 ? S 09:40 0:00 dovecot/config dovenull 25364 0.0 0.0 20908 4080 ? S 09:41 0:00 dovecot/pop3-login [127.0.0.1] dovecot 25365 0.0 0.0 100236 7776 ? S 09:41 0:00 dovecot/auth [0 wait, 0 passdb, 0 userdb] root 25368 0.0 0.0 132168 856 pts/1 S+ 09:41 0:00 grep dovecot
so there is a client connected and one dovecot/config. Lets reload:
[root@ixion-pld ~]# doveadm reload [root@ixion-pld ~]# ps aux|grep dovecot root 25333 0.0 0.0 13872 2752 ? Ss 09:40 0:00 /usr/sbin/dovecot dovecot 25336 0.0 0.0 9480 924 ? S 09:40 0:00 dovecot/anvil [2 connections] root 25344 0.0 0.0 9612 2428 ? S 09:40 0:00 dovecot/log root 25346 0.0 0.0 12920 3700 ? S 09:40 0:00 dovecot/config dovenull 25364 0.0 0.0 20908 4080 ? S 09:41 0:00 dovecot/pop3-login [127.0.0.1] dovecot 25365 0.0 0.0 100236 7776 ? S 09:41 0:00 dovecot/auth [0 wait, 0 passdb, 0 userdb] root 25371 0.0 0.0 9612 2196 ? S 09:41 0:00 dovecot/log root 25373 0.0 0.0 12496 3196 ? S 09:41 0:00 dovecot/config root 25375 0.0 0.0 132168 856 pts/1 S+ 09:41 0:00 grep dovecot
now we have two dovecot/config processes. Second dovecot/config stays there until client disconnects (what for?).
When clients disconnects we are back to single dovecot/config:
[root@ixion-pld ~]# ps aux|grep dovecot root 25333 0.0 0.0 13872 2752 ? Ss 09:40 0:00 /usr/sbin/dovecot dovecot 25336 0.0 0.0 9480 924 ? S 09:40 0:00 dovecot/anvil [0 connections] root 25371 0.0 0.0 9612 2196 ? S 09:41 0:00 dovecot/log root 25373 0.0 0.0 12496 3196 ? S 09:41 0:00 dovecot/config root 25418 0.0 0.0 132168 852 pts/1 S+ 09:43 0:00 grep dovecot
Now on production server where are tons of clients this looks more insane:
# ps aux|grep dovecot/config | wc -l 56
Note that I'm running with shutdown_clients = no here (+ high performance auth/login variant).
So looks like something is not right here. Obviously with shutdown_clients=yes this doesn't occur since clients are disconnected.
doveadm reload can happen every 2 minutes (because dovecot requires reload when SSL certificates change; new domain gets added, new cert gets automatically created -> reload, certificate is renewed (every 2 months) -> reload etc)
-- Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org )