[Mimedefang] memory leak?

[Ron Peterson]

On Mon, 9 Feb 2004, David F. Skoll wrote:
> On Mon, 9 Feb 2004, Ron Peterson wrote:
> 
> > This system has 6GB RAM.  On boot, after everything gets going, the system
> > consumes just under 1GB.  Over time, this useage is slowly creeping
> > up.
> 
> Which process is growing?  (Use "ps" to find the process with the large
> VSZ entry.)

No single process is getting too large.  Sorting 'top' by memory useage
shows the mimedefang processes at the top, all using the expected 20-30MB.

> When you say the usage is creeping up, how do you know?  Linux, by default,
> will use up all free memory for buffer cache purposes.  It is normal
> for a Linux system to show practically 100% memory usage after it has been
> running for a while.
>
> MIMEDefang is supposed to be highly resistant to memory leaks, but it's not
> impossible that there are some.

What we have been seeing is that the system's memory useage slowly (over a
day or two) creeps up to full utilization.  Then the swap space starts
being used.  I don't know how hard it's getting hit, just that it goes
from 0% to something slightly more than 0%.

That would all be o.k., but for the fact that the load average also
spikes.  We're running a load average just over 1% right now.  The CPUs
are over 80% idle.  Everything is going full bore.  By tomorrow morning, I
expect the load average to be over 50, and the CPU idle to be way
down.  This machine is also serving IMP, and those users start dropping
off and complaining.  That function has existed for quite some time now
without any problems.

So my memory leak theory might be off-base, but something unhealthy is
happening.. :\

BTW, this machine is running the 2.4.24 kernel.

> Are you using a virus scanner?  Could that be the problem?

Nope.  Just Spamassassin.

Any ideas about what might bring the machine to it's knees like this?

_________________________
Ron Peterson
Network & Systems Manager
Mt. Holyoke College
rpeterson at mtholyoke.edu