pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  
help / color / mirror / Atom feed
large number of connected connections to postgres database (v8.0)
2+ messages / 2 participants
[nested] [flat]

* large number of connected connections to postgres database (v8.0)
@ 2007-07-17 18:51  Fei Liu <fei.liu@aepnetworks.com>
  0 siblings, 1 reply; 2+ messages in thread

From: Fei Liu @ 2007-07-17 18:51 UTC (permalink / raw)
  To: pgsql-performance@postgresql.org, Fei Liu <fei.liu@aepnetworks.com>

It appears my multi-thread application (100 connections every 5 seconds) 
is stalled when working with postgresql database server. I have limited 
number of connections in my connection pool to postgresql to 20. At the 
begining, connection is allocated and released from connection pool as 
postgres serves data request. The pool can recover from exhaustion. But 
very quickly (after about 400 client requests), it seems postgres server 
stops serving and connection to postgres server is not released any more 
resulting a resource exhausting for clients.

Anyone have experience with the performance aspect of this?

Fei
unix  3      [ ]         STREAM     CONNECTED     1693655 
31976/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693654 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693653 
31975/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693652 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693651 
31974/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693650 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693649 
31973/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693648 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693647 
31972/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693646 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693645 
31971/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693644 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693641 
31969/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693640 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693639 
31968/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693638 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693637 
31967/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693636 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693585 
31941/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693584 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693583 
31940/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693582 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693581 
31939/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693580 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693579 
31938/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693578 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693577 
31937/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693576 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693575 
31936/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693574 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693573 
31935/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693572 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693571 
31934/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693570 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693427 
31851/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693426 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693425 
31777/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693424 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693419 
31764/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693418 
31740/ns_ge_classif


unix  3      [ ]         STREAM     CONNECTED     1693655 
31976/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693654 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693653 
31975/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693652 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693651 
31974/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693650 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693649 
31973/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693648 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693647 
31972/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693646 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693645 
31971/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693644 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693641 
31969/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693640 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693639 
31968/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693638 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693637 
31967/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693636 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693585 
31941/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693584 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693583 
31940/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693582 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693581 
31939/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693580 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693579 
31938/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693578 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693577 
31937/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693576 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693575 
31936/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693574 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693573 
31935/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693572 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693571 
31934/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693570 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693427 
31851/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693426 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693425 
31777/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693424 
31740/ns_ge_classif
unix  3      [ ]         STREAM     CONNECTED     1693419 
31764/postgres: pos /tmp/.s.PGSQL.5583
unix  3      [ ]         STREAM     CONNECTED     1693418 
31740/ns_ge_classif




^ permalink  raw  reply  [nested|flat] 2+ messages in thread

* Re: large number of connected connections to postgres database (v8.0)
@ 2007-07-20 23:28  Josh Berkus <josh@agliodbs.com>
  parent: Fei Liu <fei.liu@aepnetworks.com>
  0 siblings, 0 replies; 2+ messages in thread

From: Josh Berkus @ 2007-07-20 23:28 UTC (permalink / raw)
  To: pgsql-performance; +Cc: Fei Liu <fei.liu@aepnetworks.com>

Fei Liu,

> It appears my multi-thread application (100 connections every 5 seconds)
> is stalled when working with postgresql database server. I have limited
> number of connections in my connection pool to postgresql to 20. At the
> begining, connection is allocated and released from connection pool as
> postgres serves data request. The pool can recover from exhaustion. But
> very quickly (after about 400 client requests), it seems postgres server
> stops serving and connection to postgres server is not released any more
> resulting a resource exhausting for clients.

This sounds more like a problem with your connection pool.  Unless 
PostgreSQL is slowing down due to CPU/RAM/I/O saturation?

In any case, I doubt the problem is too many connections, or you'd just get 
an error message ...

-- 
--Josh

Josh Berkus
PostgreSQL @ Sun
San Francisco



^ permalink  raw  reply  [nested|flat] 2+ messages in thread


end of thread, other threads:[~2007-07-20 23:28 UTC | newest]

Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2007-07-17 18:51 large number of connected connections to postgres database (v8.0) Fei Liu <fei.liu@aepnetworks.com>
2007-07-20 23:28 ` Josh Berkus <josh@agliodbs.com>

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox