Re: QMail Performance Question & Miscellaneous Issues

[Dave Sill]

"Bryan White" <[EMAIL PROTECTED]> wrote:

>Do you have any feel for how to evaluate what is an optimum number of
>remotes?

Measure the delivery rate at various settings of concurrencyremote.
Choose the setting that yields the highest delivery rate.

>At 400 remotes I still have 80% CPU idle time.

400 qmail-remote processes running, or concurrencyremote=400? Some
systems never hit their concurrencyremote due to I/O restriction.

>The load average
>is around 4.  This suggests to me that the system is limited by disk I/O,
>network I/O or the responsiveness of remote servers.

You should be able to monitor disk I/O rates and see if they go up as
concurrencyremote is raised. Same with network I/O.

>...  If it is the responsiveness of remote servers then more remotes
>will help.

So add more remotes. If it helps, you aren't I/O (network or disk)
limited yet.

-Dave