postgresql hanging (blocking) with smp kernel

Marcel Groner

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 "replicatio n" 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.

I also tried with other kernel-releases (the one on the master
2.4.22-1.2188.nptlsmp and the one on the slave 1
2.4.22-1.2115.nptlsmp) but it doesnt help neither.
does anyone know what this could be?

thanks alot
marcel

Nov 23 '05 #1

Subscribe Reply

2313

Gaetano Mendola

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 "replicatio n" 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_activit y"
"select * from pg_locks"
Regards
Gaetano Mendola

Nov 23 '05 #2

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