APAR status
Closed as program error.
Error description
See https://github.com/OpenLiberty/open-liberty/issues/18530 and https://github.ibm.com/WASL3/MDV/issues/69 for more information
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: Users of WebSphere Liberty with restrictive * * maxThreads configurations * **************************************************************** * PROBLEM DESCRIPTION: Server startup can hang with * * restrictive maxThreads configurations * **************************************************************** * RECOMMENDATION: * **************************************************************** A change was made in Liberty fixpack 21.0.0.7 to improve diagnostic tracing for hostname lookups. When the server thread count is restricted - for example with <executor maxThreads="6"/> - and a large number of apps are deployed, the hostname lookup code change can cause a deadlock during plugin- cfg.xml generation at server startup. A javacore for this problem will contain a stack like: 3XMTHREADINFO "Default Executor-thread-3" J9VMThread:0x00000000006E8900, omrthread_t:0x00007F5138005928, java/lang/Thread:0x00000007001E36E0, state:P, prio=5 ... 3XMCPUTIME CPU usage total: 9.448750727 secs, current category="Application" 3XMTHREADBLOCK Parked on: java/util/concurrent/FutureTask@0x00000007334DA3D0 Owned by: <unknown> 3XMHEAPALLOC Heap bytes allocated since last GC cycle=4096 (0x1000) 3XMTHREADINFO3 Java callstack: 4XESTACKTRACE at sun/misc/Unsafe.park(Native Method) 4XESTACKTRACE at java/util/concurrent/locks/LockSupport.parkNanos(LockSupport.jav a:226(Compiled Code)) 4XESTACKTRACE at java/util/concurrent/FutureTask.awaitDone(FutureTask.java:437(Co mpiled Code)) 4XESTACKTRACE at java/util/concurrent/FutureTask.get(FutureTask.java:215) 4XESTACKTRACE at com/ibm/wsspi/channelfw/utils/HostNameUtils.doPrivilegedWithTime outWarning(HostNameUtils.java:343) 4XESTACKTRACE at com/ibm/wsspi/channelfw/utils/HostNameUtils.tryResolveHostName(H ostNameUtils.java:230) 4XESTACKTRACE at com/ibm/ws/webcontainer/osgi/mbeans/PluginGenerator.tryDetermine HostName(PluginGenerator.java:2069) 4XESTACKTRACE at com/ibm/ws/webcontainer/osgi/mbeans/PluginGenerator.buildServerT ransportData(PluginGenerator.java:1379) 4XESTACKTRACE at com/ibm/ws/webcontainer/osgi/mbeans/PluginGenerator.generateXML( PluginGenerator.java:487) 5XESTACKTRACE (entered lock: com/ibm/ws/webcontainer/osgi/mbeans/PluginGenerator@0x0000000733 4E1EB0, entry count: 1) 4XESTACKTRACE at com/ibm/ws/webcontainer/osgi/mbeans/GeneratePluginConfigMBean.ge neratePluginConfig(GeneratePluginConfigMBean.java:160) 5XESTACKTRACE (entered lock: com/ibm/ws/webcontainer/osgi/mbeans/GeneratePluginConfigMBean@0x 0000000701269D58, entry count: 1) 4XESTACKTRACE at com/ibm/ws/webcontainer/osgi/mbeans/GeneratePluginConfigMBean.ge neratePluginConfig(GeneratePluginConfigMBean.java:262) ...
Problem conclusion
Liberty has been updated to avoid this deadlock scenario. See https://github.com/OpenLiberty/open-liberty/issues/18530 for more information. The fix for this APAR is currently targeted for inclusion in fix pack 21.0.0.10. 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
PH40879
Reported component name
WAS LIBERTY COR
Reported component ID
5725L2900
Reported release
CD0
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2021-09-24
Closed date
2021-09-24
Last modified date
2021-11-11
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
WAS LIBERTY COR
Fixed component ID
5725L2900
Applicable component levels
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSD28V","label":"WebSphere Application Server Liberty Core"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"CD0"}]
Document Information
Modified date:
12 November 2021