Re: Postgres DB crashing

On 6/18/2013 10:31 AM, bhanu udaya wrote:
> My PostgresSQL (9.2) is crashing after certain load tests. Currently,
> postgressql is crashing when simulatenously 800 to 1000 threads are
> run on a 10 million records schema. Not sure, if we have to tweak some
> more parameters of postgres. Currently, the postgressql is configured
> as below on a 7GB Ram on an Intel Xeon CPU E5507 2.27 GZ. Is this
> postgres limitation to support only 800 threads or any other
> configuration required. Please look at the log as below with errors.
> Please reply

thats an insanely high number of connections on a quad core processor.
in general, any more than 2-4X the number of cpu hardware threads in
concurrent queries is counterproductive and will result in higher
overhead and less throughput. if you have a real world use case for
800-1000 client threads and your workload is predominately short fast
transactions ("OLTP"), you should use a connection pooler like pgbouncer
and limit the number of active connections to something like 32 on your
4 core/8 thread CPU.

--
john r pierce 37N 122W
somewhere on the middle of the left coast