WAS v8.5 > WebSphere applications > Service integration > Message stores > Data storesData store life cycle
Starting or deleting a messaging engine affects the life cycle of its data store. Appropriate actions must be carried out on the data store.
Start the messaging engine
When you start a messaging engine, it performs checks on the tables that comprise the data store to determine whether they are suitable. If the tables do not exist, and we have selected the Create tables option when configuring the messaging engine, the messaging engine attempts to create the tables. If we have not selected this option, the database administrator must create the tables beforehand, using the data definition language (DDL) statements generated by the sibDDLGenerator command.
Make sure the database containing the data store is available before starting the messaging engine, or the server that is hosting the messaging engine. If the database is unavailable for more than 15 minutes, the messaging engine cannot connect to the data store, fails to start, and might enter the stopped state. Restart the application server to start the messaging engine.
Stopping the database
To stop the database containing the data store, ensure the messaging engine is stopped first. If the messaging engine is running and has exclusive locks on the data store, stopping the database can cause the messaging engine to be in an inconsistent state, because the messaging engine might continue to run and accept work. The same behavior occurs if the database fails while the messaging engine is running.
We can configure the messaging engine and its hosting server to shut down and restart when the database connection is lost, to prevent such inconsistencies. To configure this behavior, set the sib.msgstore.jdbcFailoverOnDBConnectionLoss custom property on the messaging engine. We can also tune your system to decrease the probability of the messaging engine failing to start before the database becomes available.
Remove a messaging engine
When you remove a messaging engine, WebSphere Application Server (base) does not delete the data store tables automatically. To re-create the same messaging engine, first delete the previous set of tables. If you create a messaging engine with existing tables, these tables must be empty, so the messaging engine can function correctly. Refer to the documentation for the chosen relational database management system (RDBMS) for information about how to delete tables. However, if we have created a data store with default settings, we do not have to delete previous tables.
Related
Remove a messaging engine from a bus
Tune the detection of database connection loss
Configure messaging engine and server behavior when a data store connection is lost
Reference:
sibDDLGenerator command
Data store tables