PM79340; 8.0.0.5: storage leak of x'48 bytes in single servant environment

Download Description

PM79340 resolves the following problem:

ERROR DESCRIPTION:
x'48' or 72 byte storage is leaked when creating HTTP session. This affects only servers in a single Servant environment. The problem does not exist for multiple Servant environments.

Sample storage:
00000000 00000002 00000000 00000002 | ................ |
B1234567 A681C7C8 00000000 00000048 | .#Eg...........H |
00000000 7CB76FD2 00000048 0B2184D0 | ....|.o....H.!.. |
00000000 00000048 43413838 44434143 | .......HCA88DCAC |
34424443 35333835 30303030 30304538 | 4BDC5385000000E8 |
30303030 30303032 30393241 37364530 | 00000002092A76E0 |
2D577971 36714E57 6A7A776B 474C5A73 | -Wyq6qNWjzwkGLZs |
56305765 4A554200 B7654321 A0C7C226 | V0WeJUB..eC!...& |

LE Heappool trace showed the following code requested this storage:

j9mem_allocate_memory_basic
j9mem_allocate_memory
jniArrayAllocateMemoryFromThread
Z_GETSTRINGUTFCHARS
getStringUTFChars
Java_com_ibm_ws390_rt_HTTPSessionAffinity_registerSession
RUNJAVATHREAD
javaProtectedThreadProc
j9sig_protect
javaThreadProc

This problem can manifest itself as much larger storage leak due to Java JNI caching being enabled. For more information on -Xjni:arrayCacheMax, refer to this DOC apar PM79234.

LOCAL FIX:
Local fix is being tested.

PROBLEM SUMMARY

USERS AFFECTED:
All users of IBM WebSphere Application Server V8.0 and V8.5

PROBLEM DESCRIPTION:
Native storage leak in WebSphere Application Server for z/OS servant process.

RECOMMENDATION:
None

Two storage leaks may occur in the servant when configured in single server mode (wlm_dynapplenv_single_server=1). There are two unique native storage leaks identified by this
APAR. The first leak can occur creating an HTTP Session. The leak has been identified as x'48' bytes obtained using a JNI service. The following is an example of an instance of this leaked storage:

00000000 00000048 |................|
43413543 33373737 38463435 32363833 |CA5C37778F452683|
30303030 30324143 30303030 30303035 |000002AC00000005|
30393241 37363634 4C757A69 7569656E |092A7664Luziuien|
57626364 30726956 6D70447A 78446C00 |Wbcd0riVmpDzxDl |

The second leak identified with this APAR occurs when an EJB Stateful Object is created in the Single Server mode. The leak is typically x'14' bytes in length obtained from the LE heap. It typically contains a UUID value. The following is an example of an instance of this leaked storage:
CAB64103 ABB3078A 00000180 00000001
00000000

PROBLEM CONCLUSION:
Code has been modified to correct the two leaks in the native code paths discussed above.

APAR PM79340 is currently targeted for inclusion in Fix Packs 8.0.0.6 and 8.5.0.2 of WebSphere Application Server.

Please refer to the Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?uid=swg27004980

In addition, please refer to URL:
http://www.ibm.com/support/docview.wss?uid=swg27006970
for Fix Pack PTF information.