Hi, I have a similar configuration using AIX, Linux/ppc, IBM sdk,  
openjdk , DB2 and Websphere or jetty.

To make it short. If your Websphere crashes it creates an heapdump,  
composed of 2 or 3 files. You should find these files in your profile  
directory (something like /opt/IBM/Webspere/AppServer/profiles/server1).

There is an IBM tool
http://www.alphaworks.ibm.com/tech/heaproots

for analyzing the dump. For large heapdumps , please dont use the GUI  
version, otherwise the utility would create an heapdump for itself :-(.
Command Line operation is needed.

Within the last 3 years, this utility helps me to solve any problem  
concerning memory problems and finding the code causing these problems.

I would recommend you to invest some time, I am sure this is not the  
last heapdump you have to study. Believe me, it is the best way to  
find the problem.

If you have questions, please ask, I will support you.

I can also analyze your heapdump, but this requires at minimum one day  
and this is part of my commercial support for customers.

Hope this helps









Quoting Andrea Aime <[email protected]>:

> Rob ha scritto:
>> I'm seeing a serious problem with my geoserver install, where it is
>> crashing the system it is running on, following certain types of WMS
>> requests.
>>
>> Given the fact that I am probably the only person on the list running
>> GeoServer (v2.0.0) under WebSphere App Server, using IBM Java, on AIX, I
>> am not expecting anybody to point me in the direction of a silver
>> bullet.  However, if someone could confirm my theory as to what is
>> happening that is causing the issue in the first place, it might help.
>> I'll try and talk through an example, and my hypothesis - made with no
>> knowledge of the geoserver code whatsoever, I hasten to add! :)
>>
>>
>> FOR AN EXAMPLE WAYWARD REQUEST
>>
>> I am rendering some vector data stored in Oracle Spatial.  This data is
>> quite detailed, and from the geoserver debug logs, I can identify the
>> exact SQL used. I can run the SQL in sqlplus and the records return
>> pretty much instantaneously.  There are eight polygons, and eight lines.
>>  The lines and polygons have between 50 and 300 vertices, and are styled
>> in different ways.  The MBR for these records is approx 2km by 1.5km.
>>
>> These records render beautifully, and quickly (1-2 seconds) at 1:2000.
>> [To my simple mind, this suggests that the geometries are valid, and
>> that the styling is OK.  I remember seeing an issue with symbols at
>> these kind of scales causing problems, but none of these records would
>> be styled using symbols.  Basic lines and fills only]
>>
>> As I zoom in (and in, and in)  the rendering starts to take more time
>> each time, until I'm at something like 1:50.  Rendering is now taking 20
>> seconds.  If I zoom in until I'm at 1:2 or 1:1, I can see the memory on
>> the machine be eaten up, until WebSphere starts paging like crazy and
>> eventually the machine hangs.
>>
>> My theory is that GeoServer is trying to create an image at the same
>> scale as the target bbox, but containing the entire geometries pulled
>> back from Oracle.  So if I request a 600x600 pixel image at 1:1 scale,
>> it tries to build an internal image that would contain the 2km x 1.5km -
>> i.e., a (600 x 2000=1200000) x (600 x 1500=900000) image, before it
>> would cut out the 600x600 bbox of interest.
>>
>> Is this how it works?
>>
>> GeoServer does have some WMS resource consumption limits that I can
>> configure, and I have these currently set to
>>
>> Max rendering memory - 73728 KB (up from 64Mb, as I was seeing some
>> OutOfMemory issues on something else)
>> Max rendering time - 20s (down from 60s - see below)
>> Max rendering errors - 100 (down from 1000)
>>
>> Changing the max rendering time seems to have helped, as GeoServer cant
>> eat all the available memory and pagespace inside 20 seconds (so far
>> anyway - touch wood!), but I would have hoped that if it was a memory
>> issue, that the limit stated here would be adhered to.  I'd rather
>> GeoServer barfed an OutOfMemory error than it taking down my entire
>> server.  Should this limit have stopped the problem?
>>
>> The next thing for me to try (within GeoServer at least) is to try and
>> set up some MinScaleDenominators in the SLDs so that these features
>> aren't displayed beyond 1:10.
>>
>> Are there any other suggestions on how to make this work/fallover
>> gracefully?
>
> My guess is that you're using a dash array on the lines of those
> polygons. There is a well known java2d bug that makes the rendering
> bomb out.
>
> We could clip the line before passing it to the renderer, but doing it
> properly is not easy and so far nobody every had spare time to work on
> it, nor paid time.
>
> Cheers
> Andrea
>
>
> --
> Andrea Aime
> OpenGeo - http://opengeo.org
> Expert service straight from the developers.
>
> ------------------------------------------------------------------------------
> The Palm PDK Hot Apps Program offers developers who use the
> Plug-In Development Kit to bring their C/C++ apps to Palm for a share
> of $1 Million in cash or HP Products. Visit us here for more details:
> http://p.sf.net/sfu/dev2dev-palm
> _______________________________________________
> Geoserver-users mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/geoserver-users
>



----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.



------------------------------------------------------------------------------
This SF.net email is sponsored by 

Make an app they can't live without
Enter the BlackBerry Developer Challenge
http://p.sf.net/sfu/RIM-dev2dev 
_______________________________________________
Geoserver-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/geoserver-users

Reply via email to