Create the database for schedulers

Each scheduler requires a database in which to store its persistent information. Schedulers use this database for storing tasks and then running them. The choice of database and location should be determined by the application developer and server administrator.

Scheduler performance is ultimately limited by database performance. If we need more tasks per second, we can run the scheduler daemons on larger systems, use clusters for the session beans used by the tasks or partition the tasks by using multiple schedulers. Eventually, however, the scheduler database becomes saturated, and a larger or better-tuned database system is needed. For detailed information on scheduler topologies refer to the "WebSphere Enterprise Scheduler planning and administration guide" technical paper.

Multiple schedulers can share a database when specified unique table prefix values in each scheduler configuration. This sharing can lower the cost of administering scheduler databases. However, do not configure schedulers with non-unique table prefixes such that two separate servers share the same database table. A lease occurs between a specific database table and a scheduler running on a server. This lease allows one server at a time to own the lease to a specific database table. This process exists to ensure that one server runs schedule events, such as EJB timers, in a cluster environment. If the server with this lease is unavailable, another server in the cluster obtains the lease.

Complete the following steps to create scheduler databases.

1. Create a database. To create the database for a scheduler or to determine if an existing database is adequate for a scheduler, review the Create scheduler databases topic.

2. Create the scheduler tables. There are three methods for creating the tables for a scheduler:

   1. Create tables for schedulers using the administrative console. Use the administrative console to add, delete and verify database tables through the Web browser. This method is ideal for developers and simple scheduler topologies.

   2. Create tables for schedulers using JMX or scripting.

      Use JMX to add, delete and verify database tables programmatically with Java or scripting. This method is ideal for automating scheduler configurations for simple scheduler topologies.

   3. Create tables for schedulers using DDL files. Manually edit the DDL files using the favorite text editor, and verify that mapping between the table names and the scheduler resources and data sources is correct.

• Create scheduler databases
  The scheduler uses the scheduler database for storing and running tasks. To create a scheduler database, the database system must be installed and available.

• Scheduler table management functions
  The administration console and the WASSchedulerConfiguration MBeans provide simplified methods for creating scheduler tables and schema, verifying that the scheduler tables and schema are setup properly and are accessible and removing scheduler tables and schema.

• Scheduler table definition
  Schedulers require database tables and indices with a table prefix. This page provides reference information about the tables.

• Create scheduler tables using the administrative console
  To create scheduler tables using the administrative console, the scheduler requires a database, a Java DataBase Connectivity (JDBC) provider and a data source.

• Create scheduler tables and JMX
  Creating scheduler tables and JMX requires a database, a Java DataBase Connectivity (JDBC) provider, and a data source.

• Create scheduler tables using DDL files
  Create scheduler tables using DDL files.

Related concepts

Use wsadmin scripting with JMX

Related tasks

Use the administrative console

Related information:

WebSphere Enterprise Scheduler planning and administration guide