Oracle-Connection-Pooling in Java

[Umberto Nicoletti]

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