[Mimedefang] Problems with Mimedefang & Spamassassin

[Matt Yahna]

(This message was posted to the Spamassassin list as well, but was told it
would be better here)

We currently use the following configuration for blocking Spam:

Solaris 8
Mimedefang 2.41
SpamAssassin 2.63
Perl 5.8.0
Sendmail 8.12.11

Over the weekend, I noticed several message in the syslog that the milter
timed out, and that some messages were taking several hours to finally get
through the system.  We were still blocking spam, but it was taking a long
time.  I was getting reports from users that they were not getting messages
from clients, and would see in the log that their message was refused
because the milter was too busy to accept it.  This never used to happen, we
would get emails right away even after they went through SA.  I have tried
adding more mimedefang instances to the multiplexor, but they just get used
and get busy.  I have 20 running right now, and all are busy.  Does anyone
have any idea why this just started happening?  I thought maybe it was
because of some of the new rules that I installed, but even after turning
most of them off, I still have the problem!  I have the following rules
installed (all downloaded recently):

99_FVGT_Tripwire.cf          airmax.cf      random.current.cf    antidrug.cf
backhair.cf                  sa-blacklist.cf	bigevil.cf
sa-blacklist.current.uri.cf		bogus-virus-warnings.cf
chickenpox.cf
evilnumbers.cf               weeds.cf

I ran a spamassassin -d --lint and receive no errors.

Here are some of the errors in my syslog:

Mar 24 09:33:42 spawn mimedefang-multiplexor: [ID 316382 mail.info] Killing
busy slave 17 (pid 23428): Busy timeout Mar 24 09:33:42 spawn
mimedefang[5240]: [ID 847421 mail.error] Error from
multiplexor: ERR Filter timed out - system may be overloaded (consider
increasing busy timeout)Mar 24 09:33:44 spawn mimedefang-multiplexor: [ID
364399 mail.info] Slave status: Stopped=0 Idle=0 Busy=20 Killed=0 Queued=0
Msgs=3193 Activations=3183Mar 24 09:33:44 spawn sm-mta[23419]: [ID 801593
mail.error] i2OGSDCS023419: Milter (mimedefang): timeout before data read
Mar 24 09:33:45 spawn sm-mta[23419]: [ID 801593 mail.info] i2OGSDCS023419:
Milter (mimedefang): to error state
Mar 24 09:32:10 spawn sm-mta[23532]: [ID 801593 mail.info] i2OGW3iQ023532:
Milter: data, reject=451 4.7.1 Please try again later

One of the things I just noticed was the following log entry (after changing
back to 10 max slaves):

Mar 24 10:25:42 spawn mimedefang-multiplexor: [ID 472408 mail.info] Slave
status
: Stopped=0 Idle=0 Busy=10 Killed=0 Queued=0 Msgs=3 Activations=10

Why would 10 of them be busy with only 3 messages?  Or does that mean that
10 messages have come through to the filter, and it has let 3 pass?  

Here are more log messages (after turning sendmail logging up).  It seems to
try to quit the filter, but doesn't actually shut the filter down?  I am not
sure.  I can't seem to find any other indication of a problem other than it
complaining that it can't connect to the filter and these types of messages
repeating in syslog:

Mar 24 10:26:03 spawn sm-mta[29020]: [ID 801593 mail.info] NOQUEUE: connect
from
 66-95-174-36.client.dsl.net [66.95.174.36]
Mar 24 10:26:04 spawn sm-mta[29020]: [ID 801593 mail.info] i2OHQ38X029020:
Milte
r (mimedefang): init success to negotiate
Mar 24 10:26:04 spawn sm-mta[29020]: [ID 801593 mail.info] i2OHQ38X029020:
Milte
r: connect to filters
Mar 24 10:26:04 spawn mimedefang[28186]: [ID 627436 mail.warning] mfconnect:
No 
free slaves
Mar 24 10:26:04 spawn sm-mta[29020]: [ID 801593 mail.info] i2OHQ38X029020:
milte
r=mimedefang, action=connect, tempfail
Mar 24 10:26:04 spawn sm-mta[29020]: [ID 801593 mail.info] i2OHQ38X029020:
Milte
r (mimedefang): time command (C), 0
Mar 24 10:26:04 spawn sm-mta[29020]: [ID 801593 mail.info] i2OHQ38X029020:
Milte
r: connect, ending
Mar 24 10:26:04 spawn sm-mta[29020]: [ID 801593 mail.info] i2OHQ38X029020:
Milte
r (mimedefang): quit filter 

I did notice that I am running perl 5.8.0, and not the latest (5.8.3).  So I
am currently compiling 5.8.3 to see if it helps.

Any help would be greatly appreciated.
 
- Matt