[Mimedefang] Broken Pipe in Milter?

[David F. Skoll]

On Mon, 8 Jul 2002 Dale_Whiteaker-Lewis at dell.com wrote:

> Thanks for the feedback, David.  I should be more clear, when I get these
> messages, they are almost all I get, in addition to a smaller number of the
> MIMEDefang errors mentioned below;  no mail appears to be successfully
> delivered.

Weird.  How much memory does your machine have?

> Of more concern to me now is the advent of the problem of
> mimedefang-multiplexor dying when under high load.  This has happened on all
> 4 remaining machines at some point today.  This may be due to my experiment
> with setting the maximum instances of mimedefang.pl to 30.  I've sinced
> scaled it back to 15 and, as yet, the problem has not recurred.

The multiplexor shouldn't die unless you are running out of memory.
Linux 2.4 has (IMO) rotten behaviour when memory is low -- it starts
killing processes at random (or at least I can't discern any pattern.)

I recommend using the "-R" and "-M" mimedefang-multiplexor options on
production servers.  These options limit the memory consumption of slaves.
A value of 30000 (30000K = 30M) seems reasonable on x86/Linux.  If a slave
exceeds this memory consumption, it is killed, but at least it can prevent
your entire system from being dragged down.  (It is possible to craft
special malicious MIME messages which cause MIME::Tools to consume almost
unbounded memory.  You want to catch those.)

> Tomorrow
> will be a big day for MIMEDefang here, as we see how it performs under a
> weekday load.  Wish me luck.

Good luck! :-)

Regards,

David.