At 12:40 PM -0400 5/16/96, Chris Farris wrote:
> You are the best sendmail guru I know of, maybe you could answer a
> question I've been having...
Dunno if you meant to send this to the list or me privately, but
I'll answer anyway. ;-)
> Is there an inherent danger or problem in having a large outgoing queue.
> We are running a mailing list of about 2000 users, and when I run a
> mailq the result is about 70K lines long. Often it seems that the
> messages are being held up at an address because of routing or
> nameserver problems. I have not noticed a performance problem, but I
> have also been trying to keep the queue length down. Unfortuantly I'm
> starting up several more lists, and this will soon be impossible to do.
In my experience, whenever the mqueue gets over about 10K
messages in it, it starts getting slower to pull messages out than it
is to put new ones in and you then have a serious problem.
For this situation, I recommend multi-level or split queueing
straties with multiple mqueue directories. For multi-level queues,
start with Paul Pomes' re-mqueue program posted to comp.mail.sendmail
last year (might be on some old news archives).
Alternatively, on one of the pages in the book _sendmail_ by
Bryan Costales, there is a shell script for finding messages with
certain recipient strings in the addresses, and it should be
relatively easily modified to handle searching for messages older
than a certain age, and therefore candidates for mv'ing to another
mqueue that gets processed more slowly.
Be careful to ensure that the queue periodicity for your
multi-level queues is such that they never get in sync and you get
hundreds of copies of sendmail all firing up simultaneously. If
they're all set to prime numbers, then if they ever do get in sync,
on the very next run-through they'll de-synchronize themselves.
You might also want to investigate using sendmail 8.7.5 and
making use of it's QueueSortOrder=host option.
Brad Knowles, MIME/PGP: brad @
comp.mail.sendmail FAQ Maintainer <http://www.his.com/~brad/>
finger brad @
com for my PGP Public Keys and Geek Code
The comp.mail.sendmail FAQ is at <http://www.his.com/~brad/sendmail/>