Enabling SOA Using WebSphere Messaging

22 Enabling SOA Using WebSphere Messaging

2.2 WebSphere Application Server

The foundation of the WebSphere brand is the application server, which provides

the runtime environment and management tools for J2EE and Web services

based applications. WebSphere Application Server provides qualities of service

like clustering, failover, scalability, and security. It also includes a built-in

messaging provider, which can be configured to connect to an existing

WebSphere MQ network.

WebSphere Application Server is available in three packages:

򐂰 WebSphere Application Server Express

The Express package is geared to those who need to get started quickly with

e-business. It is specifically targeted at medium-sized businesses or

departments of a large corporation, and is focused on providing ease of use

and ease of application development. It contains full J2EE 1.4 support but is

limited to a single-server environment. WebSphere Application Server -

Express is bundled with the Rational Web Developer application development

tool.

򐂰 WebSphere Application Server

The WebSphere Application Server package provides the next level of server

infrastructure. Though the server is functionally equivalent to the server

shipped with Express, this package differs slightly in packaging and licensing.

IBM Message Service API (XMS):

This book focuses on JMS applications; however, you should be aware of the

IBM Message Service API (XMS). XMS is a programming API that allows

access from C, C++, and .NET applications to the following IBM messaging

servers:

򐂰 WebSphere MQ

򐂰 WebSphere Message Broker real-time transport

򐂰 WebSphere Application Server V6 default messaging provider

Similar to JMS, it provides a mechanism for non-Java applications to

participate in point-to-point and pub/sub messaging. It supports both

synchronous and asynchronous messaging styles.

򐂰 Introducing XMS -- The IBM Message Service API

http://www-128.ibm.com/developerworks/websphere/library/techarticles/0509

_phillips/0509_phillips.html

Chapter 2. Product selection 23

The development tool included is a trial version of a Rational Application

Developer, full J2EE 1.4 compliant development tool.

򐂰 WebSphere Application Server Network Deployment

WebSphere Application Server Network Deployment is an even higher level

of server infrastructure in the WebSphere Application Server family. It

extends the WebSphere Application Server base package to include

clustering capabilities, Edge components, and high availability for distributed

configurations. These features become more important at larger enterprises,

where applications tend to service a larger client base, and more elaborate

performance and availability requirements are in place.

The basic architectural model for WebSphere Application Server is shown in

Figure 2-2 on page 24.

24 Enabling SOA Using WebSphere Messaging

Figure 2-2 Architectural model of WebSphere Application Server

The architectural model for Network Deployment is similar to this, but adds a

deployment manager for central administration and management for all

application servers grouped together in a cell. In Network Deployment, the admin

services resides in the deployment manager. Multiple servers are possible and

application server clustering is used for workload management and high

availability.

WebSphere Application Server V6 provides full support for the J2EE 1.4

specification. The J2EE specification defines the concept of containers to provide

runtime support for applications. There are three types of containers in the

application server implementation:

򐂰 Web container

Web container

Web

browser

client

HTTP server

Web server

plug-in

Application Server

Admin

tools

Admin service

EJB container

Java client

Client container

Name Server (JNDI)

Security server

Web Services engine

Messaging engine

Web Service

Provider or

Gateway

Bus

Msg

Queue

service

destinations

Application

Database

JCA services

EIS