Re: [Exim] Performance question

Michael Brutman wrote:
> I'm running exim 3.36 and trying to stress it to see how it behaves.

If you want to setup a new system, consider to use exim4.

> Kernel profiling is telling me that it spends a lot of time creating
> processes - 60% of the CPU time is spent in kernel mode. I understand from

When a process is in kernel-mode it doesn't mean that it just spents
time for creating processes ;).
MTAs are VERY IO-Bound, so what you see is mostly fs/network IO.

> Is there a way to cut down on the number of processes that exim is using
> for delivery? I've examined the queue running options, but none of those
> address the delivery mechanism.
>
> For the curious, the machine is a 2 way PowerPC box. Disk I/O seems
> sufficient, and I have far more memory than I can use. With mstone driving
> the workload it is using 1.5GB, and I've got another 14.5GB to go. :-)
> Networking is a single 100Mb/s ethernet card, which at the moment isn't
> working too hard. The machine is using a 2.4.19 kernel.

If you have many queued_files, use split_spool_directory.
Setup a local caching dns, or nscd.
Tune your FS.

ciao