IBM Patterns for SOA
- By John K. Waters
IBM is billing the software development patterns just published on its developerWorks
Web site as the first designed to assist in the creation of service-oriented
The six new patterns, grouped as the WebSphere Platform Messaging Patterns
Asset, focus on Enterprise Service Bus connectivity using the new messaging
engine in IBM's WebSphere Application Server 6.0. They include well-known mediation
patterns, such as message logging and message transformation, as well as topology
patterns for configuring the service integration bus and message queues.
"ESB is the heart of SOA," says Angel Diaz, director of on-demand
software development in IBM's Software Group. "An ESB can support the SOA
goals of shared services and reuse, and help to eliminate the task of managing
The patterns are packaged as reusable assets that can be imported and installed
into the company's Rational Software Architect development environment. Users
launch the RAS Asset Explorer and connect to the Rational XDE Repository. The
URL is accessible only through the RAS Asset Explorer, not from a Web browser.
In software development, a pattern is the description of a recurring solution
to a standard problem. Collections of interrelated patterns are called pattern
languages, which, though not formal languages, provide a vocabulary for talking
about a particular problem. As a literary form, patterns have required developers
to manually implement code according to the pattern guidelines. IBM is eliminating
the pencil-and-paper process by creating a repository of coded patterns accessed
through the RSA tool.
The six new patterns include:
- Message Delegate: creates a client to send a message over JMS
- Message Logger Mediation: logs messages into database for audit purposes
- XSLT Mediation: transforms message from one format to another using an XSLT
- Mediaton List Handler: configures a list of mediations that can be invoked
in a sequence
- Service Integration Bus: configures the bus resources on WebSphere V6.0
- JMS Connection: configures JMS resources on WebSphere 6.0
IBM's first group of coded development patterns, called the Enterprise Patterns
Asset, was published earlier this summer. Since then, the company has built
a new site within developerWorks dedicated to patterns.
"We're building a community around patterns," says Grant Larsen,
model driven development strategist for IBM Rational. "You're going to
see more and more patterns released on the site, and not just from IBM."
The first software patterns were written by object-oriented developers in the
1990s, but they have roots in a design movement of the same name in contemporary
architecture. The idea grew out of the writings of architect Christopher Alexander,
who published several books on urban planning and building architecture. Patterns
were brought to the attention of the developer community in 1995 with the publication
of Design Patterns: Elements of Reusable Object-Oriented Software, by Erich
Gamma, Richard Helm, Ralph Johnson and John Vlissides (best known today as The
Gang of Four).
The new patterns are available as free downloads from the developerWorks Pattern
Solutions Web site. The newly launched site, which IBM hopes will become a one-stop
shop for its growing patterns community, lists the latest patterns, including
source code, and provides links to a patterns resource center, with content
to help organizations with their pattern-based development. It's located at:
John K. Waters is a freelance writer based in Silicon Valley. He can be reached
at [email protected].