[Mimedefang] Rapidly exhausting all slaves

[Brian Landers]

I'm seeing some very odd symptoms on my inbound mail relays.  From time
to time, something appears to cause slaves to hang in rapid succession.
First, all available slaves become busy one after the other, then the
multiplexor starts spawning more slaves which immediately become busy.
This continues until it his the maximum number of slaves, at which point
it starts tempfailing mail.

I'm only sending messages 100k or below through spamassassin, and 90% of
the time everything works fine, just occasionally the box will "freak
out"

Is this just a case of a sudden burst of mail overwhelming my server, or
could something else be going on?  Are there things I can tune in either
the sendmail or mimedefang configs to make my servers more resistant to
these floods of mail?

My setup:
* Solaris 8 on Ultra 5, 512mb, load spead across multiple servers
* sendmail 8.12.6
* mimedefang 2.28
* perl 5.8.0
* spamassassin 2.43

see below for a relevant log sample

Jan 23 13:03:06 cammextmail02 mimedefang-multiplexor: [ID 778059
mail.info] Starting slave 3 (pid 12647) (15 running): About to
perform scan

Jan 23 13:03:07 cammextmail02 sm-mta[12646]: [ID 801593 mail.info]
(regular sendmail "from" entry snipped)

Jan 23 13:03:07 cammextmail02 mimedefang-multiplexor: [ID 778059
mail.info] Starting slave 8 (pid 12648) (16 running): About to
perform scan 

Jan 23 13:03:09 cammextmail02 sm-mta[12649]: [ID 801593 mail.info]
(regular sendmail "from" entry snipped)

Jan 23 13:03:09 cammextmail02 mimedefang-multiplexor: [ID 778059
mail.info] Starting slave 18 (pid 12651) (17 running): About to
perform scan

Jan 23 13:03:10 cammextmail02 sm-mta[12650]: [ID 801593 mail.info]
(regular sendmail "from" entry snipped)

Jan 23 13:03:10 cammextmail02 mimedefang-multiplexor: [ID 778059
mail.info] Starting slave 10 (pid 12652) (18 running): About to
perform scan

Jan 23 13:03:15 cammextmail02 sm-mta[12653]: [ID 801593 mail.info]
(regular sendmail "from" entry snipped)

Jan 23 13:03:16 cammextmail02 mimedefang-multiplexor: [ID 778059
mail.info] Starting slave 9 (pid 12654) (19 running): About to
perform scan

and so on up to the max. number of slaves allowed.

Many thanks in advance,
Brian