Fixes are available
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for AIX
7.0.0.15: Java SDK 1.6 SR9 Cumulative Fix for WebSphere Application Server
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for HP-UX
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for IBM i
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Linux
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Solaris
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Windows
7.0.0.17: WebSphere Application Server V7.0 Fix Pack 17
7.0.0.17: Java SDK 1.6 SR9 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.19: WebSphere Application Server V7.0 Fix Pack 19
7.0.0.21: WebSphere Application Server V7.0 Fix Pack 21
7.0.0.23: WebSphere Application Server V7.0 Fix Pack 23
7.0.0.25: WebSphere Application Server V7.0 Fix Pack 25
7.0.0.27: WebSphere Application Server V7.0 Fix Pack 27
7.0.0.29: WebSphere Application Server V7.0 Fix Pack 29
6.1.0.47: WebSphere Application Server V6.1 Fix Pack 47
7.0.0.31: WebSphere Application Server V7.0 Fix Pack 31
7.0.0.27: Java SDK 1.6 SR13 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.33: WebSphere Application Server V7.0 Fix Pack 33
7.0.0.35: WebSphere Application Server V7.0 Fix Pack 35
7.0.0.37: WebSphere Application Server V7.0 Fix Pack 37
7.0.0.39: WebSphere Application Server V7.0 Fix Pack 39
7.0.0.41: WebSphere Application Server V7.0 Fix Pack 41
7.0.0.43: WebSphere Application Server V7.0 Fix Pack 43
7.0.0.45: WebSphere Application Server V7.0 Fix Pack 45
6.1.0.43: Java SDK 1.5 SR13 Cumulative Fix for WebSphere Application Server
6.1.0.45: Java SDK 1.5 SR14 Cumulative Fix for WebSphere Application Server
6.1.0.47: Java SDK 1.5 SR16 Cumulative Fix for WebSphere Application Server
7.0.0.19: Java SDK 1.6 SR9 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.21: Java SDK 1.6 SR9 FP2 Cumulative Fix for WebSphere
7.0.0.23: Java SDK 1.6 SR10 FP1 Cumulative Fix for WebSphere
7.0.0.25: Java SDK 1.6 SR11 Cumulative Fix for WebSphere Application Server
7.0.0.27: Java SDK 1.6 SR12 Cumulative Fix for WebSphere Application Server
7.0.0.29: Java SDK 1.6 SR13 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.45: Java SDK 1.6 SR16 FP60 Cumulative Fix for WebSphere Application Server
7.0.0.31: Java SDK 1.6 SR15 Cumulative Fix for WebSphere Application Server
7.0.0.35: Java SDK 1.6 SR16 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.37: Java SDK 1.6 SR16 FP3 Cumulative Fix for WebSphere Application Server
7.0.0.39: Java SDK 1.6 SR16 FP7 Cumulative Fix for WebSphere Application Server
7.0.0.41: Java SDK 1.6 SR16 FP20 Cumulative Fix for WebSphere Application Server
7.0.0.43: Java SDK 1.6 SR16 FP41 Cumulative Fix for WebSphere Application Server
Obtain the fix for this APAR.
APAR status
Closed as program error.
Error description
Classloader memory leak in Naming CacheManager in the servant region. Leak occurs if applications are started and stopped many times such as in a stress test. Example of leak: 0x14c52e700 com/ibm/ws/naming/jcache/CacheKey@66c366c3 0x14ad88ad0 java/util/HashMap$Entry@67146714 0x14471a228 java/util/HashMap$Entry@55905590 0x14e2a8d58 [Ljava/util/HashMap$Entry;@711b711b 0x128487320 class com/ibm/ws/naming/jcache/CacheManager@6bc46bc4 0x128a99668 org/eclipse/osgi/internal/baseadaptor/DefaultClassLoader@7f5f7f5 f [truncating at system class LEAK]
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: Users of IBM WebSphere Application Server * * Network Deployment versions 7.0 on z/OS * **************************************************************** * PROBLEM DESCRIPTION: Slow memory leak of classloader in * * CacheManager when applications are * * started and stopped repeatedly. * **************************************************************** * RECOMMENDATION: * **************************************************************** Naming cache is used to speed up lookup. For java namespace caches, CacheManager uses the associated context classloader as part of the key to lookup the cache instance. This works as design on distributed platforms. However, since the NameServerImpl, which registers an deployment listener to clears out caches during the application stop, runs in the control region, while the CacheManager and runs in the servant region, the classloader did not get clear out on z/OS. Thus, a minor memory leak of classloader is seen in CacheManager in the servant region on z/OS when applications is started and stopped repeatedly over time. This memory leak should only be a concern during stress test. Under normal usage, this leak does not have a noticeable impact.
Problem conclusion
The ServantNameServiceImpl registers a listener to remove classloader used as cache key in the CacheManager when application is stopped. The slow memory leak of classloaders in servant region is removed. APAR PM20539 is currently targeted for inclusion in Service Level 7.0.0.15 of WebSphere Application Server. Please refer to URL: //www.ibm.com/support/docview.wss?rs=404&uid=swg27006970 for Fix Pack availability.
Temporary fix
Comments
APAR Information
APAR number
PM20539
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-08-13
Closed date
2010-11-08
Last modified date
2011-04-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500
Applicable component levels
R700 PSY UK65060
UP11/03/04 P F103
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
Document Information
Modified date:
24 October 2021