PI76509:Hang on org/apache/webbeans/context/sessioncontext.addchildrequest

Download Description

PI76509 resolves the following problem:

ERROR DESCRIPTION:
Hanging threads after applying fix pack 8.5.5.11 / 8.0.0.13 or liberty
16.0.0.4 or 17.0.0.1

SystemOut.log and Java cores show:

[9-2-17 16:13:45:421 CET] 0000002f ThreadMonitor W WSVR0605W:
Thread "WebContainer : 35" (0000011d) has been active for 697463
milliseconds and may be hung. There is/are 1 thread(s) in
total in the server that may be hung.
at
java/util/HashMap.put(HashMap.java:506(Compiled
Code)) at java/util/HashSet.add(HashSet.java:229(Compiled Code))
at
org/apache/webbeans/context/SessionContext.addChildRequest(Sessi
onContext.java:118(Compiled Code))
at
org/apache/webbeans/web/context/WebContextsService.initRequestCo
ntext(WebContextsService.java:550(Compiled Code))
at
org/apache/webbeans/web/context/WebContextsService.startContext(
WebContextsService.java:417(Compiled Code))
at
com/ibm/ws/webbeans/services/JCDIWebListener.requestInitialized(
JCDIWebListener.java:321(Compiled Code))
at
com/ibm/ws/webcontainer/webapp/WebApp.notifyServletRequestCreate
d(WebApp.java:1908(Compiled Code))

Additional symptoms: session invalidation threads begin to
become blocked and an error similar to the following is logged
in javacores

Webcontainers 38,23,20,18 and 7 were blocked behind webcontainer
21 which was runnable and Owns Monitor Lock on
com/ibm/ws/session/store/memory/MemorySession@0x000000000852C740

at
java/util/HashMap$HashIterator.remove(HashMap.java:955(Compiled
Code))
at
org/apache/webbeans/context/SessionContext.isAnyRequestActive(Se
ssionContext.java:137(Compiled Code))
at
org/apache/webbeans/context/SessionContext.isAnyRequestActive(Se
ssionContext.java:123(Compiled Code))
at
org/apache/webbeans/web/context/WebContextsService.destroySessio
nContext(WebContextsService.java:717(Compiled Code))
at
org/apache/webbeans/web/context/WebContextsService.endContext(We
bContextsService.java:269(Compiled Code))
at
com/ibm/ws/webbeans/services/JCDIWebListener.sessionDestroyed(JC
DIWebListener.java:397(Compiled Code))
at
com/ibm/ws/session/http/HttpSessionObserver.sessionDestroyed(Htt
pSessionObserver.java:180(Compiled Code))
at
com/ibm/ws/session/SessionEventDispatcher.sessionDestroyed(Sessi
onEventDispatcher.java:160(Compiled Code))
at
com/ibm/ws/session/StoreCallback.sessionInvalidated(StoreCallbac
k.java:126(Compiled Code))
at
com/ibm/ws/session/store/memory/MemorySession.invalidate(MemoryS
ession.java:232)
at
com/ibm/ws/session/store/memory/MemorySession.invalidate(MemoryS
ession.java:878)

LOCAL FIX:
None

PROBLEM SUMMARY

USERS AFFECTED:
All users of IBM WebSphere Application
Server using CDI

PROBLEM DESCRIPTION:
Concurrent modification can corrupt a
HashSet leading to hanging threads

RECOMMENDATION:
None

A HashSet in the org.apache.webbeans.context.SessionContext
was undergoing concurrent modification. A hanging
thread with SessionContext on the stack is likely to be
resolved by this APAR.

PROBLEM CONCLUSION:
The Set in question was updated to use a different Set
implementation that can accept concurrent modification.

The fix for this APAR is currently targeted for inclusion in
fix packs 8.5.5.12, 8.0.0.14 and Liberty 17.0.0.2. Please
refer to the Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980