A fix is available
APAR status
Closed as program error.
Error description
Threads are being reported as hung in a callstack similar to the following: "WebContainer : 24" J9VMThread:0x0000000009917000, j9thread_t:0x00007F428C76C900, java/lang/Thread:0x00000006A9144098, state:CW, prio=5 (java/lang/Thread getId:0x365, isDaemon:true) (native thread ID:0x698B, native priority:0x5, native policy:UNKNOWN, vmstate:CW, vm thread flags:0x00000101) (native stack address range from:0x00007F427E2B8000, to:0x00007F427E2F8000, size:0x40000) CPU usage total: 26.985705856 secs, current category="Application" Waiting on: com/ibm/ws/wsoc/WsocConnLink$1@0x00000006B4669E10 Owned by: <unowned> Heap bytes allocated since last GC cycle=0 (0x0) Java callstack: at java/lang/Object.wait(Native Method) at java/lang/Object.wait(Object.java:172(Compiled Code)) at com/ib m/ws/wsoc/WsocConnLink.finishReadBeforeClose(WsocConnLink.java:8 14) at com/ibm/ws/wsoc/SessionImpl.close(SessionImpl.java:394) at com/ ibm/ws/wsoc/EndpointManager.httpSessionExpired(EndpointManager.j ava:166) at com/ibm/ws/wsoc/WsocHttpSessionListener.sessionDest royed(WsocHttpSessionListener.java:63) at com/ibm/ws/webcontain er/managedobject/ManagedObjectListenerWrapper.sessionDestroyed(M anagedObjectListenerWrapper.java:90) at com/ibm/ws/session/http /HttpSessionObserver.sessionDestroyed(HttpSessionObserver.java:2 02) at com/ibm/ws/session/SessionEventDispatcher.sessionDestroy ed(SessionEventDispatcher.java:160) at com/ibm/ws/session/Store Callback.sessionInvalidated(StoreCallback.java:126(Compiled Code)) at com/ibm/ws/session/store/memory/MemorySession.invalid ate(MemorySession.java:226(Compiled Code)) at com/ibm/ws/sessio n/store/memory/MemorySession.invalidate(MemorySession.java:894) at com/ibm/ws/session/store/memory/MemoryStore.checkSessionStill Valid(MemoryStore.java:429(Compiled Code)) at com/ibm/ws/sessio n/SessionManager.getSession(SessionManager.java:492(Compiled Code)) at com/ibm/ws/session/SessionManager.getSession(SessionM anager.java:475(Compiled Code)) at com/ibm/ws/session/SessionMa nager.getSession(SessionManager.java:706(Compiled Code)) at com /ibm/ws/session/SessionContext.getIHttpSession(SessionContext.ja va:490(Compiled Code)) at com/ibm/ws/session/SessionContext.ses sionPreInvoke(SessionContext.java:647(Compiled Code)) at com/ib m/ws/webcontainer/srt/SRTRequestContext.sessionPreInvoke(SRTRequ estContext.java:69(Compiled Code)) These threads may block other threads. Also, the threads may never come out of this state, eventually resulting in exhaustion of the thread pool.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of Websockets on IBM WebSphere * * Application Servers * **************************************************************** * PROBLEM DESCRIPTION: Reading a Websocket message on a * * connection while also closing the * * same connection may hang a thread due * * a race condition. * **************************************************************** * RECOMMENDATION: * **************************************************************** Thread is hung in Websocket code. Thread was reading data on a Websocket connection while another thread was closing the same connection.
Problem conclusion
Code was added to fix a race condition. The fix for this APAR is currently targeted for inclusion in fix pack 9.0.5.3 and Liberty 19.0.0.8 Please refer to the Recommended Updates page for delivery information: http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
Temporary fix
Comments
APAR Information
APAR number
PH18898
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
900
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2019-11-06
Closed date
2019-11-25
Last modified date
2019-11-25
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
WEBS APP SERV N
Fixed component ID
5724H8800
Applicable component levels
R900 PSY
UP
[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.0","Line of Business":{"code":"LOB45","label":"Automation"}}]
Document Information
Modified date:
02 November 2021