A fix is available
APAR status
Closed as program error.
Error description
The servant abends caused by hung threads in JDBC Driver. After 5 minutes of seeing the hang, the control region (CR) kills the servant. The method com.ibm.ws.rsadapter.spi.WSManagedConnectionFactor Impl$Equals.checkPrivateCredentials() in J2C component is causing a deadlock. This method checkPrivateCredentials() is expected to be invoked in multi threaded environment. A javacore taken at the time of the deadlock will show the following: 1LKDEADLOCK Deadlock detected !!! NULL --------------------- NULL 2LKDEADLOCKTHR Thread "ORB.thread.pool : 0" (0x00000000412BCC00) 3LKDEADLOCKWTR is waiting for: 4LKDEADLOCKMON sys_mon_t:0x00000000826641D0 infl_mon_t: 0x0000000082664240: 4LKDEADLOCKOBJ java/util/Collections$SynchronizedSet@00000000031930E0/000000000 31930EC: 3LKDEADLOCKOWN which is owned by: 2LKDEADLOCKTHR Thread "ORB.thread.pool : 4" (0x0000000042945800) 3LKDEADLOCKWTR which is waiting for: 4LKDEADLOCKMON sys_mon_t:0x00000200121AC420 infl_mon_t: 0x00000200121AC490: 4LKDEADLOCKOBJ java/util/Collections$SynchronizedSet@000000000329CFC8/000000000 329CFD4: 3LKDEADLOCKOWN which is owned by: 2LKDEADLOCKTHR Thread "ORB.thread.pool : 0" (0x00000000412BCC00) The stack traces of the two threads involved in the deadlock show this: "ORB.thread.pool : 0" TID:0x00000000412BCC00, j9thread_t:0x00000200081FD4E0, state:B, prio=5 (native thread ID:0x5B85, native priority:0x5, native policy:UNKNOWN) at java/util/Collections$SynchronizedCollection.size(Collections.ja va:478(Compiled Code)) at java/util/AbstractSet.equals(AbstractSet.java:51(Compiled Code)) at java/util/Collections$SynchronizedSet.equals(Collections.java:83 1(Compiled Code)) at com/ibm/ws/rsadapter/spi/WSManagedConnectionFactoryImpl$Equals.c heckPrivateCredentials(WSManagedConnectionFactoryImpl.java:3227( Compiled Code)) at com/ibm/ws/rsadapter/spi/WSManagedConnectionFactoryImpl$Equals.r un(WSManagedConnectionFactoryImpl.java:3187(Compiled Code)) at com/ibm/ws/security/util/AccessController.doPrivileged(AccessCon troller.java:63(Compiled Code)) at com/ibm/ws/rsadapter/spi/WSManagedConnectionFactoryImpl.matchMan agedConnections(WSManagedConnectionFactoryImpl.java:2087(Compile d Code)) at com/ibm/ejs/j2c/FreePool.getMCWrapperFromMatch(FreePool.java:179 8(Compiled Code)) at com/ibm/ejs/j2c/FreePool.getFreeConnection(FreePool.java:873(Com piled Code)) at com/ibm/ejs/j2c/PoolManager.reserve(PoolManager.java:2153(Compil ed Code)) ... "ORB.thread.pool : 4" TID:0x0000000042945800, j9thread_t:0x00000200098C5CE0, state:B, prio=5 (native thread ID:0x18ED, native priority:0x5, native policy:UNKNOWN) at java/util/Collections$SynchronizedCollection.size(Collections.ja va:478(Compiled Code)) at java/util/AbstractSet.equals(AbstractSet.java:51(Compiled Code)) at java/util/Collections$SynchronizedSet.equals(Collections.java:83 1(Compiled Code)) at com/ibm/ws/rsadapter/spi/WSManagedConnectionFactoryImpl$Equals.c heckPrivateCredentials(WSManagedConnectionFactoryImpl.java:3227( Compiled Code)) at com/ibm/ws/rsadapter/spi/WSManagedConnectionFactoryImpl$Equals.r un(WSManagedConnectionFactoryImpl.java:3187(Compiled Code)) at com/ibm/ws/security/util/AccessController.doPrivileged(AccessCon troller.java:63(Compiled Code)) at com/ibm/ws/rsadapter/spi/WSManagedConnectionFactoryImpl.matchMan agedConnections(WSManagedConnectionFactoryImpl.java:2087(Compile d Code)) at com/ibm/ejs/j2c/FreePool.getMCWrapperFromMatch(FreePool.java:179 8(Compiled Code)) at com/ibm/ejs/j2c/FreePool.getFreeConnection(FreePool.java:873(Com piled Code)) at com/ibm/ejs/j2c/PoolManager.reserve(PoolManager.java:2153(Compil ed Code)) ...
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: WebSphere Application Server V7.0 for z/OS * * & distributed platforms JCA and JDBC * **************************************************************** * PROBLEM DESCRIPTION: Selectable fix for servant abends * * caused by hung threads in WebSphere * * Application Server adapter component. * **************************************************************** * RECOMMENDATION: * **************************************************************** Method com.ibm.ws.rsadapter.spi.WSManagedConnectionFactor Impl$Equals.checkPrivateCredentials() or checkPublicCrentials() in adapter component is causing a deadlock. If a customer has java cores that contain this deadlock they need to enable this fix. To enable the fix, set custom property "useRRASetEquals" of type java.lang.String to true on the datasource.
Problem conclusion
The JDK's implementation of Subject.equals() is synchronized. This fix implements an unsynchronized equals. Only enable this fix if the java cores contain a deadlock in checkPrivateCredentials() or checkPublicCredentials(). If a customer has java cores that contain this deadlock they need to enable this fix. To enable the fix, set custom property "useRRASetEquals" of type java.lang.String to true on the datasource. APAR PK75897 is currently targeted for inclusion in Service Level (Fix Pack) 7.0.0.1 of WebSphere Application Server V7.0 for z/OS. 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
PK75897
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
2008-11-18
Closed date
2008-11-19
Last modified date
2012-05-29
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
BBGUBINF BBOUBINF
Fix information
Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500
Applicable component levels
R700 PSY UK41764
UP08/12/05 P F812
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.
[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0","Edition":"","Line of Business":{"code":"LOB45","label":"Automation"}}]
Document Information
Modified date:
10 February 2022