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Where Can I find Websphere 5.0 Core/Java Heap Dump files?

We are on an older version of WAS. WAS 5.0. We are having a lot of random performance issues from our web server that sits on top of WAS.

As troubleshooting steps we want to look at the core head dump files but we cant find them. I have searched  under: C:\temp. I have also searched on all drives for: *.dmp or *.trc. but nothing.

Can someone tell me where I can look for these files?

Thanks!
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matrix0511
Asked:
matrix0511
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Gary PattersonVP Technology / Senior Consultant Commented:
Look for thread dumps in the installation root directory.  They have the following format:

javacore.date.time.id.txt.

Heap dumps:

install_root/bin/heapdmp.txt
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matrix0511Author Commented:
Ok. I didn't see any files, so I guess that is a good thing right? Thanks!
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matrix0511Author Commented:
Hey Gary, something I just noticed on the WAS server admin console setting that might explain why we are having these performance issues. NOtice the attached screen print for JVM MIN & MAX memory settings. Ideally they should be set to something like 32MB min & 1024MB max.

but notice that it's set to. do you think this could be the culprit? Perhaps its having to start so low with the memory setting?
1-15-2014-12-44-23-PM.jpg
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Gary PattersonVP Technology / Senior Consultant Commented:
Yes, or course.  Inadequate memory can cause all kinds of problems, and setting is restricting the heap to 256MB of RAM.

You've also got some debugging options turned on.  Depending what is in there, that can create a lot of overhead, too.
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matrix0511Author Commented:
You mentioned we have debugging turned on. Where did you see that??
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matrix0511Author Commented:
And shouldn't we be seeing those heap dump files no matter what? And especially with these wrong settings, I would think that there would be heap dump files all over the place. But I don't see any.
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Gary PattersonVP Technology / Senior Consultant Commented:
Debug arguments box.
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matrix0511Author Commented:
Ok. So Gary, to turn OFF debug do I just remove that debug argument? (-Xdebug)?

Or what is the best way to disable that? Thanks
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Gary PattersonVP Technology / Senior Consultant Commented:
The debug arguments are probably only applied when you check the Debug Mode box above the debug arguments.  Check the help text.
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matrix0511Author Commented:
I checked with Oracle (JDE) support and they said that argument (-Xdebug) does in fact mean debugging is turned on.

But you make an interesting point. I want to see how we can confirm if its actually debugging or not. Is there certain log files that it creates that would indicate its debugging? I would expect to see a ton of large files if this setting has been in place a long time right?
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Gary PattersonVP Technology / Senior Consultant Commented:
The question isn't what -xDebug does, it is whether or not these debug arguments are actually being applied when the JVM is started.

-xDebug enables the remote debugging service, and allows you to attach a remote debugger (from Eclipse, for example) to your application.  Usually there will be options too, including -Djava.compiler=NONE, which causes your code to run in pure interpreted mode (no JIT - which is liable to significantly slow your application down)

I think ticking the "Enable Debug" box determines whether these are applied when the JVM is started or not.  It wasn't ticked on the screen shot you posted above, so that may mean it won't be applied on the next server start.

To be sure, just read the help text on that page, it should tell you.  

Or look as your startServer.sh script.  It will contain a line like this:

export DEBUG="-Djava.compiler=NONE -Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=7777"

or

# export DEBUG="-Djava.compiler=NONE -Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=7777"

If the line is commented out, debugging is disabled.  If it is not commented out, debugging is enabled.
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