Enterprise service bus offers streamlined integration

Computerworld - The enterprise service bus as a concept has increasingly gained currency in the IT marketplace, even as vendor camps have squabbled over what exactly an ESB is. As a result, many organizations remain uncertain about the need for and role of an ESB in their IT infrastructures. Is an ESB just gussied-up message-oriented middleware, or is it a genuinely new approach to integration?

In response to client inquiries regarding the definition of an ESB, Mike Gilpin, an analyst at Forrester Research Inc., published a report in August that described the technology as "software infrastructure that enables service-oriented architectures (SOA) by acting as an intermediary layer of middleware through which a set of reusable business services are made widely available."

An ESB typically has some sort of "bus" messaging technology, such as Java Message Service or IBM's MQSeries, and support for Web services standards. The standards support is designed to let enterprises map data from disparate systems, route messages, ensure that services are delivered—and in the correct order—and enforce security rules automatically by using XML instead of changing code in the interfaces of services.

The ESB has evolved to meet users' demands for a way to integrate applications that's easier than traditional enterprise application integration. EAI systems require coding to link applications and can cost as much as 10 times more.

Enterprises are looking to ESBs to provide the runtime infrastructure for making loosely coupled applications work, says Ron Schmelzer, an analyst at ZapThink LLC in Waltham, Mass.

"If you have a bunch of services doing different things, an ESB can compose them together," he says. "It allows you to run these processes over a long period of time. This bus must be very reliable, meaning that it can guarantee that your message has been received."

The largest group of companies using ESBs are those that need Web services for integration with existing message-oriented Common Object Request Broker Architecture (CORBA) or other integration technologies, Gilpin says.

"Companies want to move toward a service-oriented approach, but they can't throw away the investments they have made so far," he notes. "The stuff you have is always a logical place to start."

For example, when Raymond James & Associates needed to integrate data from a real-time reporting system operated by the Municipal Securities Rulemaking Board (MSRB) into its trading and reporting system, it opted for an ESB tool from Iona Technologies PLC. The investment brokerage firm has been buying traditional EAI products from Iona for more than 10 years.

Using Iona's Artix ESB, Raymond James can integrate data feeds every 15 minutes detailing municipal bond trades throughout the market from the MSRB's system. The ESB allows the company to integrate feeds from MSRB's IBM WebSphere MQ messaging software into its own CORBA-based system, says Martin Kullman, vice president and manager of fixed-income technology at St. Petersburg, Fla.-based Raymond James.