Re: [Fwd: postgres 8.4.1 number of connections] - Mailing list pgsql-performance

From Scott Marlowe
Subject Re: [Fwd: postgres 8.4.1 number of connections]
Date
Msg-id AANLkTikkCJ1embk=i6V06k7sRQqv3WfGGwPLNGTGuMWV@mail.gmail.com
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In response to [Fwd: postgres 8.4.1 number of connections]  ("Maria L. Wilson" <Maria.L.Wilson-1@nasa.gov>)
Responses Re: [Fwd: postgres 8.4.1 number of connections]  (Magnus Hagander <magnus@hagander.net>)
Re: [Fwd: postgres 8.4.1 number of connections]  ("Maria L. Wilson" <Maria.L.Wilson-1@nasa.gov>)
List pgsql-performance
On Thu, Aug 26, 2010 at 2:29 PM, Maria L. Wilson
<Maria.L.Wilson-1@nasa.gov> wrote:
>
>
> we have this application (using jboss/java/hibernate) on linux accessing
> data on 3 postgres database servers using 8.4.1.
>
> One of our many concerns has been the way we handle connections to the
> database.  java/hibernate handle their own pooling so I understand that
> using anything else is out of the question.

It's not impossible to put another connection pooler between hibernate
and your database server.  May not be useful or better, but it's
possible.

>  Our jboss configuration
> currently defaults to 5 connections per database.

I assume this is for each app server.  How many app servers do you have?

>  On our main database
> server, we handle 7 of the databases that this application uses.  On
> this one server, we usually average around 300 - 500 connections to the
> server.  In our postgres conf file on this particular machine we set the
> max_connection parameter to 1000.  If we set it to much lower we end up
> with connection errors.  Any comments or better way to handle this?

Other than breaking out the databases onto their own server, or trying
to pool to fewer connections, not really.  OTOH, a db server with
enough memory can handle having that many connections as long as you
don't run into any thundering herd issues.

Oh, and you should really update your pgsql to 8.4.4.  8.4.1 had some
issues with heavy load I ran into last year about this time.  Which is
why I'm still on 8.3.11

--
To understand recursion, one must first understand recursion.

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