Greg Ames wrote: > > I had 2.0.30-dev up briefly on daedalus tonight to collect doc on our load spike > problem.
> Anyway, there's about 20 seconds worth of ktrace output at > http://www.apache.org/~gregames/ktrace. We might have some kind of thundering > herd problem - I see a whole bunch of unproductive context switches about the > time a select pops. > > Then I tried 2.0.29-dev from Nov. 15, with Ryan's patch to fix the timeouts on > top of that. That's got the load spikes as well, and that's not very long after > we tagged 2_0_28. Getting a lot closer. httpd://www.apache.org/~gregames/ktrace.2_0_28 now has 30 some seconds of ktrace for comparison purposes. Interestingly enough, this file is considerably smaller than the 2.0.30-dev file which ran for less time. There's about twice the context switches in 2.0.30-dev's ktrace. prefork was changed to do a apr_poll before the accept, even in the single listen case, on Nov 10. The polls seem to get added to the herd of selects that wake up several times a second for no real good reason. We need to get rid of this poll once again. Greg
