Configuration planning for a messaging engine to use a data store
We must consider a number of choices before configuring a messaging engine to use a data store.
Relational database management system (RDBMS) for the data store
We might want to choose the RDBMS that you use for other applications, particularly if you are already familiar with the tools you use for managing that RDBMS. We might also want to consider the following criteria:
- Performance
- Scalability
- Availability, especially if you are running messaging engines in a high availability environment
When a new messaging engine that uses a data store is created on a single server, it is configured to use an Apache Derby data source by default. This enables the messaging engine to run without needing any additional configuration. The default embedded Derby data source is sufficient for many purposes. Other relational database management systems offer more comprehensive tooling and improved performance, particularly scalability on larger machines with more than two processors.
Supported configurations: WebSphere Application Server supports direct customer use of the Apache Derby database in test environments only. The product does not support direct customer use of Apache Derby database in production environments. The product supports the use of Apache Derby only by internal application server componentsf in production environments.
Database topology
We must consider several options when selecting the relative location of a data store and its messaging engine:
- Decide whether the data store will run on the same node as its messaging engine, or on a remote node. In some cases, running the data store on a remote node can improve performance. In other cases, a local database provides performance equivalent to a remote database. We might want to conduct our own performance analysis, because the performance characteristics can be very sensitive to the hardware specification.
- Decide whether the data store will have a dedicated database, or share a database with other data stores.
- Consider the implications for high availability of the choice of topology.
Automatic creation of database tables
Consider whether we want WebSphere Application Server to create the data store tables automatically or whether we want our database administrator to create the tables beforehand:
- WAS can create the data store tables automatically if you select the Create tables option when you configure the data store to use a data source. To choose this option, first ensure that WebSphere Application Server has sufficient authority to create tables and indexes by setting up the required privileges for the chosen database.
DB2 for z/OS restriction: The option for WebSphere Application Server to create the tables is not available with DB2 for z/OS . If we use DB2 for z/OS, the database administrator must create the data store tables manually.
- To enable the database administrator to create the tables manually, provide DDL statements created using the sibDDLGenerator command.
Amount of BLOB space required to hold message data
Message data is stored in a database table column of datatype BLOB. Before creating a data store, you must consider the size of the expected workload to ensure that the database administrator creates a sufficiently large BLOB space to hold the message data.
Related concepts
Data stores Data store high availability Data store topologies
Related tasks
Configure a JDBC data source for a messaging engine Create data store tables
Data store tables Database privileges