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In order to access EJBs that are deployed to WAS V6, the client, regardless of whether it is local or remote, must first obtain a reference to objects related to an application, such as a reference to an Enterprise JavaBean (EJB) home object. This process is called EJB bootstrapping. The bootstrapping service is provided through J2EE Naming that is implemented via WebSphere CORBA CosNaming.
EJB home objects are bound into a hierarchical structure, referred to as a name space. An InitialContext is used to access objects in the name space. To obtain an InititalContext, a bootstrap server and port need to be supplied. If these are not supplied, then default values are used specific to the client type and its environment. More information about naming and name spaces can be found in the redbook WAS V6 System Management and Configuration Handbook, SG24-6451. Chapter 13 explains the concept in detail.
InitialContext requests participate in workload management when the provider URL is a clustered resource (cluster member), and they do not when they are not a clustered resource.
It is very important that you provide fault-tolerant bootstrapping information to the EJB client to allow for appserver (EJB container) failures. If the bootstrap server and port are not available, then the reference cannot be obtained. Therefore, it is highly recommended that you do not use the Deployment Manager as the bootstrapping server as the Deployment Manager can be a single point of failure in your WebSphere environment. Instead, use multiple appservers or Node Agents.
Detailed information about EJB bootstrapping can be found in Chapter 7 "EJB workload management" of the redbook IBM WebSphere V6 Scalability and Performance Handbook, SG24-6392. This chapter contains code samples and lists best practices for EJB bootstrapping.
