Transaction troubleshooting tips

 

This topic provides tips to help you troubleshoot problems with the transaction service.

• Peer recovery fails to acquire a lock

• XAER_NOTA exception logged after server fails

• Clean shutdown message is not in the message log

For messaging problems specific to WAS nodes, see other topics in the information center, such as WebSphere MQ messaging troubleshooting tips, and the Application Servers support Web site.

 

Peer recovery fails to acquire a lock

If peer recovery of a transaction fails to acquire a file lock that is needed to perform recovery processing, you should see the following messages:

[10/26/04 8:41:38:887 CDT] 00000029 CoordinationL A   CWWTR0100_GENERIC_ERROR
[10/26/04 8:41:39:100 CDT] 00000029 RecoveryHandl A   CWWTR0100E: An attempt to  acquire a file lock need to perform recovery processing failed. Either the target  server is active or the recovery log configuration is incorrect
....
[10/26/04 8:42:34:921 CDT] 00000027 HAGroupImpl   I   CWRHA0130I: The local member  of group GN_PS=fwsitkaCell01\fwwsaix1Node01\GriffinServer3,IBM_hc=GriffinCluster,type
=WAS_TRANSACTIONS has indicated that is it not alive. The JVM will be terminated.
[10/26/04 8:42:34:927 CDT] 00000027 SystemOut     O Panic:component requested panic  from isAlive

To troubleshoot the cause of failure to acquire the file lock, check the following factors:

• If you have enabled failover of transaction log recovery on the server cluster and are using a NAS devise for the transaction logs, check that the DFS level on your machine is at a correct level for the NAS DFS level. If the two levels are not correct, the transaction logs cannot be accessed.

• If you are running as non-root, check that the id numbers of the non-root user and group match on all machines involved with peer recovery.

• If you have a policy defined for transaction, review the policy to ensure that you are giving control to the correct servers (perhaps add to or reorder the preferred server list).

 

XAER_NOTA exception logged after server fails

If an appserver fails, and the end transaction record is not forced to disk immediately, you may or may not recover a transaction. WAS does not force the end record to the log, so it is up to the operating system/network file system to decide when to write to the disk. The record would be forced if the server was shutdown cleanly. The transaction service is designed to cope with the case of the end record never being written to disk - when it gets an XAER_NOTA returned from the databases.

[date time] 00000057 WSRdbXaResour E   CWWRA0302E:  XAException occurred.  
                                        Error code is: XAER_NOTA (-4).  Exception is: XAER_NOTA

If there is a transaction without an end record left in the transaction log, the transaction service tries to check with the database. If the transaction has completed, the database indicates that there is nothing to complete (XAER_NOTA). This is normal behavior, and not an error.

 

Clean shutdown message is not in the message log

When an appserver shuts down, any active transactions are rolled back. If all transactions complete successfully, message CWWTR0105I is logged, indicating a clean shutdown of the transaction service, and the next server restart does not need any recovery activity. If an appserver shuts down and message CWWTR0105I is not logged, this does not indicate a problem, but it does mean that recovery activity is required when the server restarts.

Before uninstalling the product, you should have a clean shutdown of all appservers so that you avoid data integrity problems.

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Related tasks

Troubleshooting transactions

 

Reference topic