Bug 49292

Summary:	Memory leak in org.apache.taglibs.standard.lang.jstl.ELEvaluator
Product:	Taglibs	Reporter:	pmd1nh-rm
Component:	Standard Taglib	Assignee:	Tomcat Developers Mailing List <dev>
Status:	RESOLVED INVALID
Severity:	normal
Priority:	P2
Version:	1.1
Target Milestone:	---
Hardware:	PC
OS:	Windows Server 2003
Attachments:	Snapshot shows large entries in the Map standard.1.0.6 patched for j2se 1.4 snapshot of ELEvaluator direct children snapshot new ELEvaluator

Description pmd1nh-rm 2010-05-14 10:52:23 UTC

Created attachment 25438 [details]
Snapshot shows large entries in the Map

Hi,

I got an OOM and Eclipse MAT shows a potential leak in the org.apache.taglibs.standard.lang.jstl.ELEvaluator.
 
There was a memory leak in this area and fixed via revision 580198 (Bug 31789 
http://issues.apache.org/bugzilla/show_bug.cgi?id=31789).  This fix has already been pulled into our standard.jar bundle.

I use the default exprCacheSize which is 100.  So the LRUMap size would be expected to be max out at 100.  However, the heapdump during the OOM shows that there was 1.8 million entries in the map (screenshot is attached).

Is there any potential or known issue in this LRUMap?

Thanks,

Comment 1 nebur43 2010-05-19 11:27:00 UTC

Hi,

Are you sure apply correctly the patch? These patch is must be apply not in root path, also in \src\org\apache\taglibs\standard.

And extra/collections package must be move to extra\commons\collections before running ant. (the patch is a little confusing).

Could you attach a memory snapshot for all direct ELEvaluator childrens?

Comment 2 nebur43 2010-05-19 11:35:08 UTC

Created attachment 25456 [details]
standard.1.0.6 patched for j2se 1.4

Attached the standard.jar with the patch

Comment 3 pmd1nh-rm 2010-05-19 16:26:08 UTC

Created attachment 25458 [details]
snapshot of ELEvaluator direct children

Comment 4 pmd1nh-rm 2010-05-19 16:27:28 UTC

Hi,

Yes, I'm sure that the patch has been applied correctly.  I have also downloaded your attachment of standard-1.0.6, decompiled, and compared with ours.  They are same (from the main fixes in lang.jstl.ELEvaluator and Evaluator to the extra files in extra.commons.collections.*).  I attached the snapshot of ELEvaluator's direct children

Thanks!

Comment 5 nebur43 2010-05-20 05:35:34 UTC

Hi again,

I just have tested the jar and seems to work correctly. 

Sorry, but your jar seems not to be correctly. In your first snapshot you can see these:

 - ELEvaluator
    - Colletions
        -HashMap
            -.... lots of HashMap

In my snapshot I attach today, yo can see:

  - ELEvaluator
    - Colletions
        -LRUMap
            - AbstractHasedMap
            - 79 AbstractLinkedMap


So you are using the old ELEvaluator. Be sure your ELEvaluator are in:

 org\apache\taglibs\standard\lang\jstl

and not in:

 standard\lang\jstl

Or if you prefer, test my jar file.

Comment 6 nebur43 2010-05-20 05:38:46 UTC

Created attachment 25461 [details]
snapshot new ELEvaluator

Comment 7 pmd1nh-rm 2010-05-20 13:10:05 UTC

Hi,

Can you please share the application/JSP source that you used to test this?  I don't have a test case for this as the dump was sent in by one of our customers. 

Thank you for your help!

Comment 8 nebur43 2010-05-21 05:31:15 UTC

Sorry, I dont have any test case. I tested it in our aplication.

Comment 9 Henri Yandell 2010-06-29 03:44:14 UTC

Noting that we just dropped the LRUMap code in trunk and replaced it with a JDK 1.5 class (LinkedHashMap). 

Looking at the comments, it looks as though the issue was resolved as a no-issue? Patch not applied on jar?

If still an issue, retrying with trunk (JSTL 1.2) would be valuable. Let me know if you need a build uploaded.

Comment 10 pmd1nh-rm 2010-06-29 10:47:28 UTC

Hi,

User's app overwrites our jar and causes this issue.

Please close down this thread.  Thank you very much for your help!

Regards,

Comment 11 Jeremy Boynes 2010-10-11 22:58:22 UTC

Resolving as per comment 10 this appears to be a user issue