WebLogic: The Definitive Guide

Managing WebLogic’s EJB Container

WebLogic’s EJB container controls the life cycle of an EJB object and provides the runtime environment for deployed EJB components. The EJB container allows a client to obtain the EJB’s home object, either through a JNDI lookup, via an EJB reference defined during deployment, or by using the EJB home handle. It provides EJBs with access to a wide range of container-managed services such as the local ENC, transactions, security, persistence, concurrency, locking, caching, clustering, and session-state replication. These services can be configured for a particular EJB component through the deployment descriptors associated with it.

In this section, we examine the life cycle of session beans in WebLogic Server and the impact on the runtime behavior of the EJB container when you adjust the EJB deployment settings. In the next section, we examine the life cycle of entity beans and how you can configure the entity bean pool, caching behavior, and EJB concurrency.

Pool of Stateless Session EJB Instances

WebLogic Server maintains a free pool of stateless session EJB instances, which stores a number of inactive, “method-ready” EJB instances. You can prepare this pool of EJB instances during server startup by specifying an initial-beans-in-free-pool element in the weblogic-ejb-jar.xml descriptor file. When a client invokes a method on a stateless session EJB, WebLogic taps into this pool of method-ready EJB instances. The EJB instance then remains active ...