WebSphere WebSphere Application Server Network Deployment, Version 6.0.x Operating Systems: AIX, HP-UX, Linux, Solaris, Windows

Restoring a data store and recovering its messaging engine

When a failure occurs which cannot be dealt with by the system, you can restore the data store or data stores from a backup. Use this task to restore a backup of a data store and to recover its associated messaging engine afterwards.

Why and when to perform this task

You should also restore the configuration files for the system, to ensure that it functions as it did at the time the backup was taken, for more information about why you should do this see The service integration environment backup. After you have restored the data store, you must restart the associated messaging engine.

When you restart a messaging engine after restoring a backup you must start it in Restart after restore mode, to minimize the effects of the messaging engine not being synchronized with any other messaging engines it was in communication with before the failure. If you restart the messaging engine in Normal mode, some of the new messages produced at this messaging engine might be discarded by the receiving messaging engine, for an indeterminate amount of time after restart. In Restart after restore mode, previously transmitted messages might be resent, potentially creating duplicates of messages that were produced before the backup was taken. However new messages are not lost or duplicated (if this is specified by the quality of service for the message).

You can restart a messaging engine in Restart after restore mode only by using the wsadmin client; you cannot do it from the administrative console. You must only start a messaging engine in this mode when starting the messaging engine for the first time after restoring the backup. After the initial restart, you can perform further restarts as normal.

Restart after restore mode is ignored if you start the server in Recovery mode. If you require both a Recovery mode start and a Restart after restore mode start:

  1. Start the server in recovery mode
  2. Wait for the startup to complete and for the server to stop
  3. Start the messaging engine in Restart after restore mode
If you see the following message in the JVM System output fileSystemOut.log, it might indicate that you have restored from a backup and restarted the messaging engine without using the Restart after restore mode.
CWSIP0784E: Messaging engine: receivingME received a message from messaging engine: producingME that was 
not expected.
To resolve this issue, stop the messaging engine and restart it in Restart after restore mode.
Note: This message might also appear in other situations, so you should restart the messaging engine in Restart after restore mode only if you know you have restored a backup.

For information on the JVM System output fileSystemOut.log and how to view it, see Viewing the JVM logs.

You can recover any number of messaging engines at the same time, by following the actions below for each messaging engine in turn.

Steps for this task

  1. Change the initial state of the messaging engine to Stop, so that the messaging engine will not be automatically restarted by a server process:
    1. Use the administrative console to select the messaging engine by clicking Service integration > Buses > [Content Pane] bus_name > [Topology] Messaging engines > engine_name.
    2. In the Initial state list, click Stopped.
    3. Click OK.
  2. Save your changes to the master configuration, ensuring that you select the Synchronize changes with Nodes check box.
  3. Stop the messaging engine if it is running (see Stopping a messaging engine for instructions on how to do this). If the messaging engine does not respond, stop the server process that is hosting the messaging engine.
  4. Restore the backup of the data store that is accessed by the messaging engine, by referring to Restoring a data store.
  5. Restore the backup of the configuration files using the backupConfig command (see Backing up and restoring administrative configurations). This backup should have been taken at the same time as the data store backup.
  6. Restart any servers that were stopped by the failure.
  7. Restart the messaging engine in Restart after restore mode by performing the following steps:
    1. Start the wsadmin client.

      For more information about the wsadmin client, see Wsadmin tool.

    2. Invoke the start command using the FLUSH parameter, on the MBean for the messaging engine, for example:
      wsadmin>set myME [$AdminControl queryNames type=SIBMessagingEngine,*]WebSphere:platform=common,
      cell=myCell,version=6.0.0.0,name=myNode.server1-myBus,
      mbeanIdentifier=cells/myCell/nodes/myNode/servers/server1/sib-engines.xml#SIBMessagingEngine_1089294328702,
      type=SIBMessagingEngine,node=myNode,process=server1
      wsadmin>$AdminControl invoke $myME state
      Stopped
      wsadmin>$AdminControl invoke $myME start{"FLUSH"} 
      wsadmin>$AdminControl invoke $myME state
      Started
    A number of messages might be output to the JVM SystemOut.log file to indicate the progress of the restart process.
  8. Check the JVM SystemOut.log file for the following message that indicates that the restart was successful, in other words, no failures occurred while attempting to restart the messaging engine.
    CWSIP0783E: Messaging engine: messagingEngine started, flush of all delivery streams completed.
    If this message does not appear, a failure has occurred which has prevented the messaging engine from restarting. Resolve the cause of the failure and repeat the Restart after restore procedure until the restart is successful.
Related concepts
Data store
Related tasks
Troubleshooting service integration technologies

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Last updated: 15 Mar 2007
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