Re: [GENERAL] where is my bottleneck?

The strace for one of the clients is a lot of data. However, it certainly
doesn't seem right that, out of the 33038 commands I captured in the
strace, 31037 of them were semop().

BTW, after watching stats a bit closer, the number of context switches is
"only" about 1000/sec with just one client attached; attaching more than
one client makes the number jump up to the 30000/sec mark.

On Sat, 2 Mar 2002, Helge Bahmann wrote:

> On Sat, 2 Mar 2002, Ben wrote:
> > I've checked all the sql commands I use, and all the lookups and updates
> > are using indices. The system isn't swapping, and posgres is using its
> > 400MB of shared buffers to good effect. I have noticed that context
> > switches seem rediculously high - about 30,000/sec, give or take 10k - but
>
> This is ridiculously high; can you attach "strace" to one of the postgres
> processes while stressing the system and send a snippet of the output?
> (strace -p <pid>)
>
> I suspect Postgres locking code may be responsible for this huge amount of
> ctx switches; if you see huge amount of pointless select() statements
> in the trace, this would prove my theory and it would be time to
> rethink the current locking strategy.
>
> Regards
> --
> Helge Bahmann <bahmann@math.tu-freiberg.de>             /| \__
> Network admin, systems programmer                      /_|____\
>                                                      _/\ |   __)
> $ ./configure                                        \\ \|__/__|
> checking whether build environment is sane... yes     \\/___/ |
> checking for AIX... no (we already did this)            |
>
>
>