Nick Christenson wrote "sendmail performance tuning." He also had a lot to do with building Earthlink's email setup (before 1998). And he got to do that kind of thing later with qpopper and other stuff. He knows a lot about tuning.
And he wrote it down. Check out his book, it may have serveral bits of useful info for you. Quoting Louis A. DeRobertis ([EMAIL PROTECTED]): > > > Hi Bart, > > I saw something similar to this before I recompiled qpopper with the > --enable-servermode option. Have you tried that? > > Regards- > > Lou > > On Mon, Jan 19, 2004 at 03:47:38PM +0100, Bart Dumon wrote: > i'm running qpopper 4.0.5 on linux (2.4.x) with maildir patch > (0.12) and pam_radius for authentication. > > right now, i'm suffering from high cpu load averages once it's > gets too busy the load will skyrocket to abnormal high values > and the service will become unavailable untill it's restarted. > this typically happens during peak times when we receive 15 pop > sessions/sec. > > at first it thought it was radius related because i'm seeing the > following error message during the peak times: > > Jan 19 14:07:41 xxx popper[13404]: pam_radius_auth: RADIUS server x.x.x.x > failed to respond > > but even with a more performant radius, the problem persists, it > looks like the radius errors are a consequence of the problem and > not the real cause. > everything is pointing in the direction of the amount of pop sessions > whenever you get to the 13-14pops/sec barrier, qpopper seems to > be giving up. it's not traffic related because the amount of traffic > is higher outside the peak hours. > > > > > > -------------------- > Louis DeRobertis > Network Administrator > Suffolk Cooperative Library System >
