Network Deployment (Distributed operating systems), v8.0 > Reference > Troubleshoot tips
Transaction troubleshooting tips
Use these tips to help you troubleshoot problems with the WAS 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 the topic about messaging troubleshooting tips, and the WAS Support web page.
Peer recovery fails to acquire a lock
If peer recovery of a transaction fails to acquire a file lock that is needed to undertake 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 needed 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 isAliveTo troubleshoot the cause of failure to acquire the file lock, check the following factors:
- If we 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 we have a policy defined for transaction, review the policy to ensure that you are giving control to the correct servers (perhaps we have to add to or reorder the preferred server list).
XAER_NOTA exception logged after server fails
If an application server fails, and the end transaction record is not forced to disk immediately, you might or might 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 shut down 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_NOTAIf 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 behavior is normal, and is not an error.
Clean shutdown message is not in the message log
When an application server 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 application server shuts down and message CWWTR0105I is not logged, this message does not indicate a problem, but it does mean that recovery activity is required when the server restarts.
Before you uninstall the product, you should have a clean shutdown of all application servers so that you avoid data integrity problems.
On the z/OS operating system, the clean shutdown message CWWTR0105I is never logged. To ensure that recovery from an RRS or XA resource perspective is not needed, you can restart the application server in recovery mode, in the system in which it is configured. In recovery mode, if there are any outstanding units of recovery (URs), the application server completes the URs, then shuts down. If there are no outstanding URs, the application server starts, then shuts down normally. Therefore, to ensure that all recovery has occurred, restart the server in recovery mode and wait until a normal shutdown.
Troubleshoot transactions
Related
Messaging troubleshooting tips
WAS Support