Chapter 2. Architecture of the commerce.connect products 9
The EJB standard is a server-side Java-based component architecture for building multi-tier,
distributed, enterprise applications. WebSphere Application Server provides such services
as:
Authentication and security services: Are provided either via the host operating system
or through Lightweight Directory Access Protocol (LDAP).
Transaction management: Ensures integrity of data, not just within a single database,
but across the enterprise.
Resource pooling: Allows more efficient use of valuable system resources. This is
especially important in a large Internet deployment scenario, where there may be
thousands rather than tens of users apparently concurrently using the system.
Clustering and high availability: Enable scalability and ease the implementation of a
fault tolerant high availability system.
Developing EJBs and deploying within WebSphere offers other key benefits that are often
overlooked in the context of a single project, but that
must be considered within the technical
strategy of the company.
For the first time in Geac’s System21 development history, they can deploy the
WebSphere-based Business Application (in the form of EJB components) that they develop
on almost any Enterprise Server where there is a business benefit. Currently Geac’s
requirements are restricted to iSeries and Windows NT or Windows 2000. But in the wider
Geac worldwide context, they could deploy onto OS/390 and most UNIX variants, including
Linux.
As the e-marketplace develops, a significant number of third-party EJB components will
become available. A simple example of this is be Secure Credit Card Authorization. Using a
common architecture across multiple components reduces the number of possible failure
points, simplifies deployment, and in this example, can actually guarantee true transaction
integrity.
2.1.2 The architecture moving forward
Java standards relating to the enterprise have evolved over the past couple of years. The
biggest push on standards by IBM, Sun, and others has been around J2EE. J2EE
encompasses all of the Java standards relating to middleware and enterprise application
development. The EJB specification is now part of the J2EE standard.
Geac’s architectural strategy is to follow, comply with, and implement J2EE solutions. For
example, in the short to medium term, Geac will:
Use JMS as its messaging subsystem with MQSeries as the message transport layer
wherever possible. This allows for maximum flexibility and reliability between Java- and
non-Java-based systems.
Ensure that the Geac’s infrastructure software, such as process.connect and
inter.connect, not only coexist on the same server as one of its WebSphere EJB-based
applications, but will take full advantage of the facilities offered by WebSphere.
Implement and support the next generation of Web Technologies such as Universal
Description, Discovery, and Integration (UDDI). For more information, see:
http://www.uddi.org
