The mailing list for listmasters using Sympa

[Thomas Berry <address@concealed>]

Sympa version 5.3
OS: RedHat Release 4.4

Has anyone experienced this behavior with Sympa:

We had four occurrences over a 9 hour period where the Sympa command 
process would mostly stop processing messages from the incoming spool 
(msg).  I say "mostly" because during this outages a small percentage of 
messages to mailing lists continued to be processed by Sympa (command) 
and distributed without a delay.  During the outages, Sympa was 
restarted, which appeared to have no effect on Sympa's recovery.


I wrote a maillog and message log trolling script to link the delivery 
path of each of the distributed messages to show the distribution 
timeline.  Here is an example of the outage I see (the time durations 
are in seconds):

ibs-help
sendmail       recd   Sep 14 07:23:23
sendmail       queued Sep 14 07:23:24 delay: 1
sympa(command) recd   Sep 14 07:44:12 delay: 1248
sympa(message) recd   Sep 14 07:44:16 delay: 4
sympa(message) dist   Sep 14 07:44:16 delay: 0
sendmail       dist   Sep 14 07:44:18 delay: 2
duration: 1255

As you can see in this example, the time it took the sympa(command) 
process to retrieve the message from the msg spool was 1248 seconds.  
That was when the "outage" itself resolved and the messages "stuck" in 
the queue were quickly distributed.

I have never seen this happen before, nor has it occurred after the 
fourth instance.

There have been no recent changes to this system's hardware or software.

Implementation notes:
MySQL database, LDAP server, and mounted filer used for the MhonArc 
repository all reside external to the Sympa server.  Inbound and 
Outbound messages to and from Sympa come from a cluster of Sendmail, Inc 
MTA appliances.