[STR-3217] Title : Memory leak occurred on the org/apache/struts/util/FastHashMap.

• Type: Bug
• Status: Open
• Priority: Critical
• Resolution: Unresolved
• Affects Version/s: 1.0.2
• Component/s: Core

Environment

IT Environment :
z/OS V1.11
WAS for z/OS 7.0.19,
Struts: The version is may be 1.0.2.:
The MANIFEST.MF file in struts.jar contents is as below.
Manifest-Version: 1.0
Implementation-Version: 1.0.2
Specification-Title: Struts Framework
Specification-Version: 1.0
Implementation-Title: Struts Framework
Extension-Name: Struts Framework
Created-By: Ant 1.4.1
Implementation-Vendor-Id: org.apache
Implementation-Vendor: Apache Software Foundation
Specification-Vendor: Apache Software Foundation

• Flags: Patch, Important
• Assignee: Unassigned
• Reporter: Jung,Joon Young
• Created: 22/Oct/12 07:02
• Updated: 26/Oct/12 01:14

Description

Hello,
Recently, we received Memory leak problems from WAS for z/OS system.
( IT Environment : z/OS V1.11,WAS for z/OS 7.0.19,
Struts: The version is may be 1.0.2.: The MANIFEST.MF file in struts.jar contents is as below.
Manifest-Version: 1.0
Implementation-Version: 1.0.2
Specification-Title: Struts Framework
Specification-Version: 1.0
Implementation-Title: Struts Framework
Extension-Name: Struts Framework
Created-By: Ant 1.4.1
Implementation-Vendor-Id: org.apache
Implementation-Vendor: Apache Software Foundation
Specification-Vendor: Apache Software Foundation )

After heap dump analysis, we found that the root cause of memory leak problems is FastHashMap.

:220,493,664 (16%) [104] 2 org/apache/struts/util/FastHashMap 0x839ba6618

There are many FastHashMap entries in the Heap dump.

How can I fix the memory leak problems from FastHashMap ?
If you know, please let me advise.
Please refer to the below result from Heap dump analysis.
I will waiting for your expertise advise.

[Heap Dump Analysis result]

223,305,648 (16%) [64] 2 com/ibm/ws/cache/servlet/ServletWrapper 0x839ba6dd0
223,305,352 (16%) [240] 20 org/apache/struts/action/ActionServlet 0x839ba6538
220,493,664 (16%) [104] 2 org/apache/struts/util/FastHashMap 0x839ba6618
220,493,416 (16%) [88] 1 java/util/HashMap 0x86f285220
220,493,328 (16%) [4,112] 230 array of java/util/HashMap$Entry 0x86f285b58
38,777,480 (2%) [72] 2 java/util/HashMap$Entry 0x86f287580 <--- 1) Please
11,773,272 (0%) [72] 3 java/util/HashMap$Entry 0x86f289110 <--- 2) refer to
11,334,272 (0%) [72] 2 java/util/HashMap$Entry 0x86f288f88 <--- 3) the below.
11,287,736 (0%) [72] 2 java/util/HashMap$Entry 0x86f288460
9,291,168 (0%) [72] 2 java/util/HashMap$Entry 0x86f286be0
8,558,520 (0%) [72] 3 java/util/HashMap$Entry 0x86f285a78
8,149,584 (0%) [72] 2 java/util/HashMap$Entry 0x86f289ab0
7,790,768 (0%) [72] 2 java/util/HashMap$Entry 0x86f289618
7,404,624 (0%) [72] 3 java/util/HashMap$Entry 0x86f289b90
7,106,208 (0%) [72] 3 java/util/HashMap$Entry 0x86f288818
7,074,480 (0%) [72] 3 java/util/HashMap$Entry 0x86f285688
4,965,384 (0%) [72] 2 java/util/HashMap$Entry 0x86f286cf8
4,888,064 (0%) [72] 3 java/util/HashMap$Entry 0x86f287b30
3,716,624 (0%) [72] 2 java/util/HashMap$Entry 0x86f287a18
3,623,008 (0%) [72] 2 java/util/HashMap$Entry 0x86f2858f0
3,439,344 (0%) [72] 3 java/util/HashMap$Entry 0x86f2888c0

1)
38,777,480 (2%) [72] 2 java/util/HashMap$Entry 0x86f287580
38,777,408 (2%) [56] 2 guar/CUST/actions/BY23YDAction 0x836b94450
38,777,352 (2%) [88] 3 com/ibm/javart/v6/cso/CSOLocalPowerServerProxy
223,305,352 (16%) [240] 20 org/apache/struts/action/ActionServlet
136 (0%) [64] 1 java/lang/String 0x834ae86d8
11,773,272 (0%) [72] 3 java/util/HashMap$Entry 0x86f289110

2)
11,178,552 (0%) [72] 2 java/util/HashMap$Entry 0x86f2890d8
11,178,480 (0%) [56] 2 guar/CCHG_RC/actions/BQ04QRAction 0x8348c3958
144 (0%) [64] 1 java/lang/String 0x834c0ac68
594,648 (0%) [56] 2 guar/EXAM/actions/BH60JJAction 0x84117e7c8
136 (0%) [64] 1 java/lang/String 0x834be7298

3)
11,334,272 (0%) [72] 2 java/util/HashMap$Entry 0x86f288f88
11,334,200 (0%) [56] 2 guar/EXAM/actions/BG78HSAction 0x830a75a60
11,334,144 (0%) [88] 3 com/ibm/javart/v6/cso/CSOLocalPowerServerProxy
223,305,352 (16%) [240] 20 org/apache/struts/action/ActionServlet
136 (0%) [64] 1 java/lang/String 0x834a83df0