Introduction: Application servers

Overview

An application server is a Java Virtual Machine (JVM) that is running user applications. The application server collaborates with the Web server to return a dynamic, customized response to a client request. Application code, including servlets, JavaServer Pages (JSP) files, enterprise beans and their supporting classes, runs in an application server. Conforming to the Java 2 platform,
Enterprise Edition (J2EE) component architecture, servlets and JSP files run in a Web container, and enterprise beans run in an EJB container.

To begin creating and managing an application server, see Administering application servers. You can define multiple application servers, each running its own JVM. Enhance the operation of an application server by using the following options:

Configure transport chains to provide networking services to such functions as the service integration bus component of IBM service integration technologies, WebSphere Secure Caching Proxy, and the high availability manager core group bridge service. See Configuring transport chains for more information.
Plug into an application server to define a hook point that runs when the server starts and shuts down. See Custom services for more information.
Define command-line information that passes to a server when it starts or initializes. See startServer command for more information.
Tuning application servers
Enhance the performance of the application server JVM. See Using the JVM for more information.
Use an Object Request Broker (ORB) for RMI/IIOP communication. See Managing Object Request Brokers for more information.

Asynchronous messaging

The product supports asynchronous messaging based on the Java Messaging Service (JMS) of a JMS provider that conforms to the JMS specification version 1.1.

The JMS functions of the default messaging provider in WebSphere Application Server are served by one or more messaging engines (in a service integration bus) that runs within application servers.

In a deployment manager cell, there can be WebSphere Application Server version 5 nodes. If a version 5 node is configured to use V5 Default Messaging (the version 5 Embedded Messaging), there can be at most one JMS server on that node.

Generic Servers In distributed platforms, the Generic Servers feature allows you create a generic server as an application server instance within the WebSphere Application Server administration, and associate it with a non-WebSphere server or process. The generic server can be associated with any server or process necessary to support the application server environment, including:

A Java server
A C or C++ server or process
A CORBA server
A Remote Method Invocation (RMI) server

After you define a generic server, you can use the Application Server administrative console to start, stop, and monitor the associated non-WebSphere server or process when stopping or starting the applications that rely on them.

For more information, refer to Creating generic servers.

Related concepts
Custom services

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