[Mimedefang] CPU load problem

[Michiel Brandenburg]

An H. Nguyen wrote:
>> "Top" shows a bunch of busy mimedefang-multiplexor processes. 
>> Mimedefang is running on a RAMDisk.
Your ps is showing no iowait so that's good.  You can get a better 
indication what your disks are doing with iostat.

> It's probably SpamAssassin.  What does strace (or "truss" if you're on 
> Solaris) say the busy processes are doing?
It's probably network related, spamassassin checks a lot of things via 
the network.  I noticed in you config you turned off most of the network 
tests, are you sure spamassassin knows this too ?  Using lsof -i4 -p 
<pid> you can check the open connections a process has.  Does it have any ?

One mail server I'm running has a constant load of 2.xx something just 
because of the spamd running on the same host ( this one has all network 
tests on btw not sure it can compare to your situation ).  In my 
situation all connections to spamd are loadbalanced to three servers.  I 
have also noticed that when increasing the amount of spam runners (in my 
case the actual scanners of spamd ) increases load but might not 
increase scanning speed.  I run with no more than 7 scanners on one 
machine.  Not sure if this is also a limitation of running spamassassin 
in mimedefang but try to decrease the amount of children that mimedefang 
uses and see if that decreases cpu time (per child ofc with the same load).

Also make sure that the DNS servers that you are using are of the 
caching kind :), lots of waiting there if they don't.  Also check the 
amount of time needed to spamscan one mail, mine is around 3 seconds.
What's you MX_REQUESTS setting ? Setting this too low will kill 
mimedefang too fast having to respawn.  Whats your volume of incomming 
mail ? 1per sec ?


--
Michiel