Re: Server response time discrepancy.

>> >> Linux lb1-dp-vm 2.6.8-3-686 #1 Tue Dec 5 21:26:38 UTC 2006 i686
>> > GNU/Linux
>> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> >
>> > could you check with "vmstat 1" that you're not approaching 50% CPU
>> > consumption on any of your old 2.6 kernels when the problem happens
>> > (servers and proxies) ? I know about a pathological CPU usage pattern
>> > for all 2.6 kernels using the scheduler before CFS (<2.6.23), which
>> > could cause large pauses to certain processes, of up to 30 seconds,
>> > though they have shrinked to about 3-4 seconds around 2.6.18. And
>> > haproxy was very good at producing those patterns. It *is* the reason
>> > why I've been staying away from 2.6 for years.

Dear Willy,

I have gathered around 18 hours of "vmstat 1" data. You may find 2 graphs here:

http://209.51.207.125/docs/tmp/HAProxy_CPU_Usage_2pm-11pm_SGT.pdf http://209.51.207.125/docs/tmp/HAProxy_CPU_Usage_11pm-8am_SGT.pdf

Are the shown trends on the graphs normal?

thanks,
unai Received on 2008/07/02 08:48