[imp] Performance scaling.

[andrew morgan]

On Wed, 26 Sep 2001, Michael Bull wrote:

> At 09:58 AM 26/09/2001 -0700, you wrote:
> >If you're using SSL, get Sun's Crypto Accelerator card.  We use that in
> >our Sun E250 doing webmail and it has made a big difference in the
> >performance.
>
> We're not using SSL... yet.   Thanks for the vote of support for the Crypto
> card, as if we're going that way, I'd want that to be added.  Glad to hear
> it's working well for others!
>
> How many processes are running on your server under a busy load?
> How busy is it?  Do you have your SQL and IMAP servers running on the same
> machine?  Our SQL server is, but we've got our own dedicated IMAP server
> serving the IMP requests.

I don't have good numbers on the logins right now.  I remember having
around 8000 per day back at the end of spring term.  We generally peak out
at around 100 apache processes during heavy load, sometimes a little
higher.  I find that if it goes much higher than that, it gets into a
runaway mode where the server can't keep up with the requests as fast as
they come in.

Right now, I'm running the SQL server on a different machine, but I would
like to run it on the same machine as webmail to simplify all the
inter-dependencies between machines.  All of the IMAP servers we let them
connect to with webmail are on other machines as well.  All this machine
does is run IMP.

The machine itself is an E250 with (2) 400MHz cpus and 1152MB of ram.

	Andy