Oracle-Connection-Pooling in Java

[Umberto Nicoletti]

I am now working on issue #1662.
Issue #1164 details how I am trying to tackle the memory leaks: with
unit tests which run a significantly smaller portion of the code. In
fact the ones in the patch run *only* the connection pooling
functions, so it should be MUCH easier to use a debugger and trace
them.

http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=1664

BTW: Benedikt, what did you use, if you did, to trace memory leaks?

Regards,
Umberto

On 2/13/06, Umberto Nicoletti <umberto.nicoletti at gmail.com> wrote:
> On 2/13/06, umn-ms at hydrotec.de <umn-ms at hydrotec.de> wrote:
> >
> > Umberto
> >
> > Thank you for taking care onon this old but still open issue!
> >
> > I created
> > http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=1661 and
> > http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=1662
> >
> > Benedikt
> >
> > (Sorry! I was not able to add your e-mail-adress to cc. Bugzilla denied to
> > do so. I suppose
> > you can handle this anyway.)
>
> I just did. I will send you a patch for the
> msConnPoolCloseUnreferenced function asap o that you can test it.
>
> Regards,
> Umberto
>
> >
> > Umberto Nicoletti <umberto.nicoletti at gmail.com> schrieb am 13.02.2006
> > 10:25:02:
> >
> >
> >  > Benedikt,
> >  > since I am looking this issue would'n t you mind opening a bug for the
> >  > inclusion of msConnPoolCloseUnreferenced in mapscript and one for the
> >  > memory leaks (add me to the cc list)?
> >  >
> >  >
> >  > Reagrds,
> >  > Umberto
> >  >
> >  > On 1/2/06, Benedikt Rothe <umn-ms at hydrotec.de> wrote:
> >  > >
> >  > > Hi list members,
> >  > >
> >  > > From former threads I got the impression, that there are some folks
> >  > > interested in the Oracle/Mapserver/Java/Tomcat.
> >  > >
> >  > > Therfore I'd like to share experiences I made with using
> > Connection-Pooling
> >  > > of
> >  > > Oracle-Connections inside Java/Tomcat.
> >  > >
> >  > > Testenvironment: Mapserver 4.6.2; Suse-Linux; Tomcat 4.1.31; Sun-Java
> > 1.4.2
> >  > > Simulating 5 Browsers, which produce maps, query features, make
> > selections,
> >  > > query-legend-pics frequently.
> >  > >
> >  > > - After using synchronized "enough" I didn't have crashes of Tomcat.
> >  > >
> >  > > - Big memory leak: Between the first 5 requests and the next 100
> > requests
> >  > >    the Tomcat-process became about 400MB bigger.  (I use "top" for
> >  > >    watching memory-footprint.)
> >  > >
> >  > > - Cleaning the Connection-Pool "by hand". This means:
> >  > >   Opening the function msConnPoolCloseUnreferenced in mappool.c
> >  > >   for use in Java and call it after every request.
> >  > >
> >  > > - After this I still have memory leaks:  About 100MB for 30.000
> > requests.
> >  > >   (I also made a test: 25.000 requests without Connection pooling.
> > Memory
> >  > > increased
> >  > >     and decreased as expected  in this case.)
> >  > >
> >  > > - Performancecomparison in my testcase:
> >  > >   Without use of connection-pooling: ~ 50 Request per minute
> >  > >   With use of connection-pooling: ~75 Request per minute
> >  > >
> >  > >
> >  > > As a result I have the following encouragements:
> >  > > - Making msConnPoolCloseUnreferenced  availabe for mapscript via swig.
> >  > >   (I made a hack by directly editing mapscript/java/mapscript_wrap.c
> > and
> >  > >    Java-Files in
> > mapscript/java/edu/umn/gis/mapscript.) I
> >  > > think this
> >  > >   function could be part of the mapscript-Object?
> >  > >
> >  > > - Investigations on the memory leaks. Both leaks shouldn't occure.
> > (I'll do
> >  > >   this, if I find time. but ...)
> >  > >
> >  > > - Fernando Simon: What about using OCI-Connection-Pooling  for oracle
> >  > > instead the mappool.c?
> >  > >
> >  > >
> > http://oraclesvca2.oracle.com/docs/cd/B14117_01/appdev.101/b10779/oci09adv.htm#452244
> >  > >   (If you don't have time, I maybe could help coding. But would it
> > become
> >  > > part uf Mapserver?)
> >  > >
> >  > > Happy new year to everybody
> >  > > Benedikt Rothe
> >
>