WAS v8.5 > Administer applications and their environment > Welcome to administering Service integration > Administer message stores > Administer data stores

Configure messaging engine and server behavior when a data store connection is lost

If the connection between a running messaging engine and its data store is lost, either due to a failure or because you stop the database for maintenance, we can ensure the messaging engine functions correctly after the connection is restored, by configuring the server to restart automatically.

The behavior described in this topic occurs only if the messaging engine is running and has established exclusive locks on its data store. By setting the sib.msgstore.jdbcFailoverOnDBConnectionLoss custom property on a messaging engine, we can determine the behavior of the messaging engine and its hosting server in the event the connection to the data store is lost.

The behavior that is determined by the sib.msgstore.jdbcFailoverOnDBConnectionLoss custom property.. The first column of the table lists the sib.msgstore.jdbcFailoverOnDBConnectionLoss custom property values. The second column explains the behavior of the messaging engine when the data store connection is lost.

Property value	Behavior when the data store connection is lost
true (default)	The server shuts down and must be manually restarted.
false	The messaging engine continues to run and accept work, and periodically attempts to regain the connection to the data store. If work continues to be submitted to the messaging engine while the data store is unavailable, the results can be unpredictable, and the messaging engine can be in an inconsistent state when the data store connection is restored. If work continues to be submitted to the messaging engine, even nonpersistent messaging can fail because the messaging engine might need to use the data store, for example to allocate a unique ID to a message, or to move nonpersistent messages out of memory.

1. Click Service integration -> Buses -> bus_name -> [Topology] Messaging engines -> engine_name -> [Additional Properties] Custom properties to navigate to the custom properties panel for the messaging engine.

2. Click New.

3. Type sib.msgstore.jdbcFailoverOnDBConnectionLoss in the Name field and true in the Value field.

4. Click OK.

5. Save your changes to the master configuration.
   

6. Restart the application server.
   

Results

If the connection between the messaging engine and its data store is lost, the application server that is hosting the messaging engine shuts down.

After a server restart, click Service integration -> Buses -> bus_name -> [Topology] Messaging engines to view the status of the messaging engine. Check the messaging engine has been restarted and is running.

You might want to tune the system so the loss of the database connection is detected quickly, and the messaging engine waits for a reasonable amount of time for the data store to become available again before attempting to start on another server.

Related

Tune the detection of database connection loss

Reference:

Service integration custom properties

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