memory leak

[DavidParker]

I am trying to track down a memory leak in our application that  
happens under moderate read/write load. It's the nature of our app  
that each write involves several reads from the db first.

I am not having much luck with the Netbeans profiler, so I'm kind of  
casting around for tools to use.

I'd like to reduce the amount of caching eclipselink does to the  
absolute minimum -for the purposes of this testing I'm not concerned  
with performance. But I'm not sure a safe way to do that. I get the  
impression from the doc that the "identity map" and "cache" are the  
same thing, and it looks like I can't run without an identity map.

What can I set in Persistence.xml to reduce caching in eclipselink?

Also, I would be really appreciative of any suggestions on how to go  
about tracking this down. My dev environment is OS X, on which JProbe,  
for instance, doesn't run. Using eclipselink 1.1.2

TIA.

- DAP

=============================================
David Parker
dap@...




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[mobrien]

David,
Hi, the SUN JDK has some rudimentry memory heap and GC tools available
via jconsole.exe in the bin directory after you attach to your java process.

See the following persistence unit property to turn off caching at the
PU level
http://wiki.eclipse.org/Using_EclipseLink_JPA_Extensions_(ELUG)#How_to_Use_the_Persistence_Unit_Properties_for_Caching

<property name="eclipselink.cache.type.default" value="NONE"/>

"NONE – This option does not preserve object identity and does not cache
objects. Oracle does not recommend using this option.
For more information, see No Identity Map. "

See the following for more granular entity level caching via annotations
for example
http://help.eclipse.org/galileo/index.jsp?topic=/org.eclipse.jpt.doc.user/task_manage_persistence.htm
http://wiki.eclipse.org/Introduction_to_Cache_(ELUG)#Unit_of_Work_Cache
http://wiki.eclipse.org/EclipseLink/Examples/JPA/Caching

thank you
/michael

David Parker wrote:

> I am trying to track down a memory leak in our application that
> happens under moderate read/write load. It's the nature of our app
> that each write involves several reads from the db first.
>
> I am not having much luck with the Netbeans profiler, so I'm kind of
> casting around for tools to use.
>
> I'd like to reduce the amount of caching eclipselink does to the
> absolute minimum -for the purposes of this testing I'm not concerned
> with performance. But I'm not sure a safe way to do that. I get the
> impression from the doc that the "identity map" and "cache" are the
> same thing, and it looks like I can't run without an identity map.
>
> What can I set in Persistence.xml to reduce caching in eclipselink?
>
> Also, I would be really appreciative of any suggestions on how to go
> about tracking this down. My dev environment is OS X, on which JProbe,
> for instance, doesn't run. Using eclipselink 1.1.2
>
> TIA.
>
> - DAP
>
> =============================================
> David Parker
> dap@...
>
>
>
>
> _______________________________________________
> eclipselink-users mailing list
> eclipselink-users@...
> https://dev.eclipse.org/mailman/listinfo/eclipselink-users

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eclipselink-users mailing list
eclipselink-users@...
https://dev.eclipse.org/mailman/listinfo/eclipselink-users

[James Sutherland]

You can disable caching in EclipseLink using the persistence.xml property,
"eclipselink.cache.shared"="false"

This is a safe configuration, and recommend if caching is not desired.  The docs are referring to using a specific NoIdentityMap cache type, which is not the correct way to disable the cache.

DavidParker wrote:

I am trying to track down a memory leak in our application that  
happens under moderate read/write load. It's the nature of our app  
that each write involves several reads from the db first.

I am not having much luck with the Netbeans profiler, so I'm kind of  
casting around for tools to use.

I'd like to reduce the amount of caching eclipselink does to the  
absolute minimum -for the purposes of this testing I'm not concerned  
with performance. But I'm not sure a safe way to do that. I get the  
impression from the doc that the "identity map" and "cache" are the  
same thing, and it looks like I can't run without an identity map.

What can I set in Persistence.xml to reduce caching in eclipselink?

Also, I would be really appreciative of any suggestions on how to go  
about tracking this down. My dev environment is OS X, on which JProbe,  
for instance, doesn't run. Using eclipselink 1.1.2

TIA.

- DAP

=============================================
David Parker
[e-mail]