The WebLogic standards-based, pure-Java application server assembles, deploys, and manages distributed Java applications. It supports distributed component services and enterprise database access, including Enterprise JavaBeans, Remote Method Invocation (RMI), distributed JavaBeans, and Java Database Connect (JDBC).

The WebLogic Server’s Administration Server is populated with JavaBean-like objects Sun Microsystem’s Java Management Extension (JMX) standard. These objects provide management access to domain resources.

The Administration Server contains both configuration MBeans and run-time MBeans. Configuration MBeans provide both SET (write) and GET (read) access to configuration attributes. Run-time MBeans provide a snapshot of information about domain resources, such as current HTTP sessions or the load on a JDBC session pool. When a particular resource in the domain (such as a Jolt connection pool) is instantiated, an MBean is created to collect information about that resource.

The WebLogic Server is configured to initialize the session pools at startup through the config.xml file. A special startup class, PoolManagerStartUp, is invoked by the WebLogic Server with a number of parameters. This class functions as follows:

• Creates a session pool manager if one does not already exist
• Creates a session pool according to the given parameters
• Adds the new session pool to the pool manager

The number of session pools created depends on the number of JoltConnectionPools that are configured in the config.xml file.