On Thu, Mar 1, 2012 at 1:52 PM, Paul Dunkler <paul.dunk...@xyrality.com> wrote: > > Hi, > > You're running on a box larger than I'm used to, so this is only speculation. > I'm wondering whether you're hitting problems with lock contention or some > such. It looks like you've got 48 cores there all at about 100% possibly none > of them getting much chance to do any work. > > > Yes. That is what i see too... > > Oddly, the totals you posted in your top output show 6.3% user cpu usage, > which I can't make match with 50-odd processes all approaching 100% cpu. > > > Sometimes the Cpu is only 7% used in this times but at other peak times, the > cpu is used 100% (97% system load) as i posted before. > > Perhaps have a look at vmstat output too - see if context-switches spike > unusually high during these periods (sorry - no idea what an unusually high > number would be on a machine like yours). > > > Thanks. i will have a look at it. > > Reducing the number of concurrent backends might help, but that rather > depends on whether my guess is right. > > > Yes... already thought about setting up a connection pool. > > If no-one more experienced than me comes along shortly, try reposting to the > performance list. There are people there who are used to machines of this > size. > > > Thanks. I will wait a time and consider re-posting it to the perfornance list. >
I'd look at vmstat and iostat output (vmstat 10, iostat -xd 10) for a few minutes. In vmstat look for high (>100k) ints or cs numbers, in iostat look at io utilization. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
