PK14278: DEADLOCK IN COM.IBM.WS.CACHE.CACHE

PK23436; 6.0.2.9: deadlock in com.ibm.ws.cache.cache code after PK14278
PK14278; 6.0.2.3: deadlock in com.ibm.ws.cache.cache

APAR status

• Closed as program error.

Error description

• Deadlock in DRS code at the following point:
  "WebContainer : 2":
    waiting to lock monitor 0x0235a6d0 (object 0x9f673dc0, a
  com.ibm.ws.cache.Cache),
    which is held by "WebContainer : 3"
  "WebContainer : 3":
    waiting to lock monitor 0x001185d0 (object 0x9f7d44f8, a
  com.ibm.ws.cache.Cache),
    which is held by "WebContainer : 2"
  
  The threads that are stuck are at:
  at com.ibm.ws.cache.Cache.trimCache(Cache.java:1576)
  - waiting to lock <0x9f7d44f8> (a com.ibm.ws.cache.Cache)
  at
  com.ibm.ws.cache.BatchUpdateDaemon.wakeUp(BatchUpdateDaemon.java
  :270)
  at
  com.ibm.ws.cache.BatchUpdateDaemon.cacheCommand_Clear(BatchUpdat
  eDaemon.
  java:101)
  at com.ibm.ws.cache.Cache.clear(Cache.java:1413)
  - locked <0x9f673dc0> (a com.ibm.ws.cache.Cache)
  at
  com.ibm.ws.cache.DistributedObjectCacheAdapter.clear(Distributed
  ObjectCa
  cheAdapter.java:402)
  at
  com.ibm.wps.services.cache.DistributedMapCache.clear(Distributed
  MapCache
  .java:113)
  at
  com.ibm.wps.services.cache.TransactionAwareCache.clear(Transacti
  onAwareC
  ache.java:168)
  at
  com.ibm.wps.ac.cache.ACCacheManager.clearDefaultFullEntitlements
  Cache(AC
  CacheManager.java:1205)
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: This problem affects all users using         *
  *                 distributed maps instances.                  *
  ****************************************************************
  * PROBLEM DESCRIPTION: Deadlock in clear commands occurs when  *
  *                      using distributed maps instances.       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The problem is that when clear commands are issued using the
  distributed Map API frequently, it might cause a cache
  deadlock.
  

Problem conclusion

• Code has been fixed to correctly handle clear commands and
  avoid the deadlock.
  
  The fix for this APAR is currently targeted for inclusion
  in fixpack 6.0.2.9.
  Please refer to the recommended updates page for delivery
  information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

Temporary fix

• ZE fix error PK23436 2006/04/20
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• DYNACACH
  

Fix information

• Fixed component name

  WEBSPH APP SERV

• Fixed component ID

  5724J0800

Applicable component levels

• R60A PSY

     UP

• R60H PSY

     UP

• R60I PSY

     UP

• R60P PSY

     UP

• R60S PSY

     UP

• R60W PSY

     UP

• R60Z PSY

     UP