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From Kristian Waagan <krist...@apache.org>
Subject Re: Performance degradation with Derby Embedded under Tomcat vs Jetty
Date Mon, 13 Apr 2015 11:12:00 GMT
Hi Øivind,

Have you turned on SQL-logging/-tracing in Derby to check the activity?

Possible things to check:
o connection IDs (distinct/count)
o expensive connection validation queries (not all of these are direct SQL,
check pool docs/conf)
o commits?
o different queries?

While one would expect the load / queries to be the same, one never knows...

In theory one would think the client driver was more affected by a pool
misconfiguration.

Regards,
-- 
Kristian
13. apr. 2015 11:56 skrev "Øyvind Harboe" <oyvind.harboe@zylin.com>:

> I've made them identical near as I can. It isn't the same
> implementation of the connection pool.
>
> Is it only EmbeddedDriver that would be negatively affected by a
> mis-configured connection pool?
>
> Is there some logging in Derby that I could enable to verify that
> things are set up correctly, i.e. that new connections are not made
> all the time?
>
>
>
> On Mon, Apr 13, 2015 at 11:16 AM, Brett Wooldridge
> <brett.wooldridge@gmail.com> wrote:
> > Are you sure that under Tomcat the application is really using the Tomcat
> > connection pool?  If not that would certainly account for the
> differences.
> > Even if Tomcat DBCP is configured, checking that the pool configurations
> are
> > similar would seem like an important check.
> >
> > -Brett
> >
> >
> > On Mon, Apr 13, 2015 at 4:56 PM, Øyvind Harboe <oyvind.harboe@zylin.com>
> > wrote:
> >>
> >> I know the Tomcat setup isn't using the clientdriver when it slows
> >> down, because when I first tried to switch to the ClientDriver it
> >> failed. After I copied the derbyclient.xxx.jar to tomcat/lib/, it
> >> worked.
> >>
> >>
> >>
> >>
> >>
> >> On Mon, Apr 13, 2015 at 9:51 AM, Dyre Tjeldvoll
> >> <Dyre.Tjeldvoll@oracle.com> wrote:
> >> > On 04/13/2015 12:27 AM, Øyvind Harboe wrote:
> >> >>
> >> >> I found another crucial clue:
> >> >>
> >> >> if I use ClientDriver instead of EmbeddedDriver and connect to the
> >> >> Derby database running under Jetty, I get identical performance with
> >> >> Tomcat and Jetty.
> >> >>
> >> >> This is very strong indication that there is something about the
> >> >> combination of EmbeddedDriver and Tomcat that is gumming up the
> works.
> >> >
> >> >
> >> > Could it be that your Tomcat setup always uses the ClientDriver for
> some
> >> > reason? I don't know much about setting up Databases with AppServers,
> >> > but
> >> > based on the number of questions on SO and other places, it isn't
> >> > trivial...
> >> >
> >> > --
> >> > Regards,
> >> >
> >> > Dyre
> >>
> >>
> >>
> >> --
> >> Øyvind Harboe - Can Zylin Consulting help on your project?
> >> http://www.zylin.com/
> >
> >
>
>
>
> --
> Øyvind Harboe - Can Zylin Consulting help on your project?
> http://www.zylin.com/
>

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