[Mailman-Users] Running large announce list & forums

[Brad Knowles]

At 6:45 AM -0700 2006-09-06, Jack Stone wrote:

>   Being a nuB to Mailman (but old hand with majordomo), I have noted that if
>  a message is being processed out to one of the large customer announcement
>  lists (10,000+) that it seems the separate discussion lists' deliveries
>  slow down substanially -- from minutes to hours! One member report 18
>  hours from post to receipt.

That could be a result of a slowdown within the Mailman queue 
processing system, or it could be a slowdown within the queue 
processing system of sendmail, once the message it out of the hands 
of Mailman.

To figure out which is which, you've got to look at the date/time 
stamps for given messages in the Mailman logs and compare those to 
the corresponding date/time stamps of the messages in the sendmail 
logs, as well as looking at the date/time stamps which are put inside 
the message itself in the "Received:" headers.

If there's a huge delay between the date/time stamp placed on the 
message by sendmail when it first gets the message from Mailman, and 
when that message for that recipient is delivered (as recorded in the 
sendmail logs), then you know that the delay is within the sendmail 
queue processing system, and you can apply all the appropriate system 
tuning procedures that are specific to that MTA.

Conversely, if there is a big gap between the logged date/time stamp 
for a given message in the Mailman logs and the delay is short 
between when sendmail records having received that message from 
Mailman and when sendmail then turns around and records that message 
as being delivered, then you know that the delay is internal to 
Mailman, and you might need to do certain other things to speed up 
the process.

>   I've read most of the "tuning" methods, but have not seen anything that
>  might be best for this, except I *think* I have noticed a speedup if I
>  don't use "personalized" stuff, like on the footers. I know it switches
>  from processing individual messages to batches. Just wonder if that really
>  is the main culprit.

That could just be because you're handling a much smaller number of 
individual messages, and doesn't really tell us if the root cause of 
the delay is internal to sendmail or if it's internal to Mailman.  We 
need more information.

>   Just wondered what others have done with this type issue. I have read most
>  of the "slow" message archives.

Without more information, it's difficult to tell.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

  Founding Individual Sponsor of LOPSA.  See <http://www.lopsa.org/>.