Oracle-Connection-Pooling in Java

[Fernando Simon]

Hi all,
    I'm working to solve this bug too.
    I'm trying to find the core of the memory leak. I will need to share 
information with Umberto about the bugs.
    Best regards.

------------------------------------------------------------------------
Fernando Simon
Mapserver and Oracle Spatial developer
G10 - Laboratorio de Computacao Aplicada - Brazil
http://www.univali.br/g10 - UNIVALI/CTTMAR
------------------------------------------------------------------------


Umberto Nicoletti wrote:
> 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
>>>
>>>       
>
>