[Mailman-Users] Stuck OutgoingRunner

[Sebastian Hagedorn]

Hi,

we've been running Mailman for many years and have never had stability 
issues, but about a month ago we moved the server from RHEL 5 to RHEL 6 and 
to the current version (2.1.25), and since then it has already happened 
twice that one of our four OutgoingRunners got "stuck" and stopped handling 
mail. When that happens a simple restart of the service does not work. 
These processes remained:

mailman   1663  0.0  0.0 233860  2204 ?        Ss   Jan16   0:00 
/usr/bin/python2.7 /usr/lib/mailman/bin/mailmanctl -s -q start
mailman   1677  0.1  0.9 295064 73284 ?        S    Jan16  35:35 
/usr/bin/python2.7 /usr/lib/mailman/bin/qrunner --runner=OutgoingRunner:3:4 
-s

root at mailman3/usr/lib/mailman/bin]$ strace -p 1677
Process 1677 attached
recvfrom(10, ^CProcess 1677 detached

[root at mailman3/usr/lib/mailman/bin]$ lsof -p 1677
COMMAND    PID    USER   FD   TYPE   DEVICE SIZE/OFF   NODE NAME
python2.7 1677 mailman  cwd    DIR    253,0     4096 173998 /usr/lib/mailman
python2.7 1677 mailman  rtd    DIR    253,0     4096      2 /
...
python2.7 1677 mailman   10u  IPv6 46441320      0t0    TCP 
mailman3.rrz.uni-koeln.de:55764->smtp-out.rrz.uni-koeln.de:smtp 
(ESTABLISHED)

In both instances the OutgoingRunner was stuck on an SMTP connection. I had 
to use "kill -9" to get rid of it.

Any ideas what might be causing that?

Cheers
Sebastian
-- 
    .:.Sebastian Hagedorn - Weyertal 121 (Gebäude 133), Zimmer 2.02.:.
                 .:.Regionales Rechenzentrum (RRZK).:.
   .:.Universität zu Köln / Cologne University - ✆ +49-221-470-89578.:.