Massive LMTP Problems with dovecot

[Stephan Bosch]

Op 10/17/2016 om 3:24 PM schreef Ralf Hildebrandt:
> Currently I'm having massive problems with LMTP delivery into dovcot.
> dovecot/lmtp processes are piling up, eas using considerable amounts
> of CPU:
>
> # ps auxwww|fgrep dove
>
> root     20537  0.0  0.0  18124  1196 ?        Ss   15:18   0:00 /usr/sbin/dovecot -c /etc/dovecot/dovecot.conf
> dovecot  20541  0.0  0.0   9620  1084 ?        S    15:18   0:00 dovecot/anvil
> root     20542  0.0  0.0   9752  1264 ?        S    15:18   0:00 dovecot/log
> root     20544  0.0  0.0  21168  2276 ?        S    15:18   0:00 dovecot/config
> copymail 20580 72.8  0.0  39556  7036 ?        R    15:18   2:00 dovecot/lmtp
> dovecot  20582  0.0  0.0  18568  1756 ?        S    15:18   0:00 dovecot/auth
> copymail 20597 77.2  0.0  35688  5136 ?        R    15:18   2:06 dovecot/lmtp
> copymail 20598 39.3  0.0  38060  5596 ?        R    15:18   1:04 dovecot/lmtp
> copymail 20613 62.3  0.0  38036  5600 ?        R    15:18   1:41 dovecot/lmtp
> copymail 20619 56.4  0.0  37732  7448 ?        R    15:18   1:31 dovecot/lmtp
> copymail 20620 75.9  0.0  35872  5336 ?        R    15:18   2:03 dovecot/lmtp
> copymail 20627 37.8  0.0  36480  5892 ?        R    15:18   1:01 dovecot/lmtp
> copymail 20838 60.5  0.0  35640  5036 ?        R    15:19   0:59 dovecot/lmtp
> copymail 20840 66.3  0.0  35920  5296 ?        R    15:19   1:04 dovecot/lmtp
> copymail 20841 66.0  0.0  37456  6852 ?        R    15:19   1:04 dovecot/lmtp
> copymail 20842 64.5  0.0  36424  5808 ?        R    15:19   1:02 dovecot/lmtp
> copymail 20843 67.6  0.0  39612  7064 ?        R    15:19   1:05 dovecot/lmtp
>
> doveadm stop won't stop these, I have to use kill -9 on them.
> I already tried disabling fts (entirely), still things won't speed up.
>
> I can't strace:
> # strace -p 20841
> Process 20841 attached
>
> (and that's it)
>
> # dpkg -l|grep dovecot
> ii  dovecot-core                        2:2.2.25-1~auto+57    amd64 secure POP3/IMAP server - core files
> ii  dovecot-imapd                       2:2.2.25-1~auto+57    amd64 secure POP3/IMAP server - IMAP daemon
> ii  dovecot-lmtpd                       2:2.2.25-1~auto+57    amd64 secure POP3/IMAP server - LMTP server
> ii  dovecot-lucene                      2:2.2.25-1~auto+57    amd64 secure POP3/IMAP server - Lucene support
> ii  dovecot-sieve                       2:2.2.25-1~auto+57    amd64 secure POP3/IMAP server - Sieve filters support
>
> I also tried deleting the mdboxes, that also didn't change anything. 
> Ideas?

We'll need the `dovecot -n` output first.

Also, you could attach gdb to one of these processes and find out where
it is stuck in what looks to be an infinite loop (produce a backtrace).

Regards,

Stephan.