Re: postgresql hanging (blocking) with smp kernel

Marcel Groner wrote:

> I have a problem with postgresql runnung on smp kernel.
>
> setup:
>
> master:
> -------
> - Pentium 4 (hyperthreading)
> - 2 GB Memory
> - os: fedora core 1
> - kernel: 2.4.22-1.2188.nptlsmp
> - postgresql: 7.4.3-1PGDG
>
> slave 1:
> --------
> - Pentium 4 (hyperthreading)
> - 2 GB Memory
> - os: fedora core 1
> - kernel: 2.4.22-1.2115.nptlsmp
> - postgresql: 7.4.3-1PGDG
>
> slave 2:
> --------
> - Double Xeon (with hyperthreading)
> - 2 GB Memory
> - os: fedora core 1
> - kernel: 2.4.22-1.2199.nptlsmp
> - postgresql: 7.4.3-1PGDG
>
>
> the "replication" is made by hand. reading from slave 1 or slave 2
> (balanced) and wrtiting to master, slave 1 and slave 2. Our site is a
> high-traffic site (the biggest dating-site in switzerland:
> www.swissflirt.ch) with > 1400 concurrent users and > 40'000 visits
> per day.
>
> master and slave 1 (with pentium 4) are working perfectly with
> smp-kernel. slave 2 (with double xeon) has big problems. running p.e.
> with kernel 2.4.22 (non smp) works also but of course only one CPU is
> used. when I use the smp kernel, the connections (and queries) are
> hanging (blocking) after some short time. Also when I shutdown the
> application (using java and jdbc to connect to the databases) the
> postgres-processes (on slave 2) keep existing while the processes on
> master and slave 1 shutdown propertly.

Hanging on what ? I'm running postgres in a similar server ( the HT
is enabled too so is like 4 CPU) without any problem at all.

Show as "select * from pg_stat_activity"
"select * from pg_locks"

Regards
Gaetano Mendola