Re: NUMA architecture and PostgreSQL

On 11/27/08, Fabricio <fabrixio1(at)hotmail(dot)com> wrote:
> I have an IBM server with NUMA architecture, two nodes with 4 CPU quad core and 64 GB of RAM each, and PostgrSQL 8.3.5.
>
> Is there any way to avoid the performance degradation when the load goes up and used the two nodes?
>
> I understand this performance degradation is due to the higher latency than a cpu access a remote memory that the local memory. But there are ways to improve this?
>
> http://archives.postgresql.org/pgsql-general/2005-04/msg01187.php

You can use sched_setaffinity to select group of cpu-s for a process
and it's childs:

http://www.kernel.org/doc/man-pages/online/pages/man2/sched_setaffinity.2.html

There is a bit higher level concept of cpusets too:

http://www.kernel.org/doc/man-pages/online/pages/man7/cpuset.7.html

In both cases, you can either patch Postgres or write a launcher
that configures CPUs before executing postgres.

--
marko