Re: Beginning tuning

From: "Phillip Mills" <pmills(at)systemcore(dot)ca>
To: "Dave Cramer" <pg(at)fastcrypt(dot)com>
Cc: pgsql-jdbc(at)postgresql(dot)org
Subject: Re: Beginning tuning
Date: 2007-11-06 14:51:54
Message-ID: dd0408e50711060651l612c941fr626777f905fed46a@mail.gmail.com
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I was rather hoping for a "go here, read this" answer as a starting point
instead of loading people down with a bunch of details. Also, I have no
evidence that JDBC is doing anything wrong; it was just the next item on my
path after determining that there wasn't any application lock silliness.
But as a software sanity check:
JBoss 4.2.1 with a JBossManagedConnectionPool of 20 (but testing with fewer
client threads)
PostgreSQL 8.1.9-1.2
postgresql-8.1-407.jdbc3.jar
(Linux OpenSUsE 10.2)

On 11/6/07, Dave Cramer <pg(at)fastcrypt(dot)com> wrote:
>
> Phillip,
>
> You'd have to give us a lot more information than this to help you.
>
> machine specs ?
> Postgresql version and jdbc version
> postgresql configuration
> are you using a db pool ?
>
> Dave
>
> On 6-Nov-07, at 9:09 AM, Phillip Mills wrote:
>
> > I'm just getting started on the process of analyzing performance for
> > a Java Enterprise application. (The main negative symptom at the
> > moment is that it doesn't use more than three processors on an eight-
> > processor system, regardless of load.)
> >
> > One of the first things I've noticed out of a number of thread dumps
> > is that there's about an 80% chance that the stack points to I/O
> > requests from PGStream.ReceiveChar(). I'm wondering about any hints
> > or pointers that would help me understand whether that's expected
> > behavior, or something that needs fixing, or just generally how to
> > evaluate/improve JDBC performance.
> >
> > (Regarding the main problem, none of my threads are reported in a
> > blocked state, leading to my focus on I/O.)
>
>

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