Amid the keen interest surrounding enterprise service buses rages a stormy debate over the exact definition of an ESB. Proponents of the Java Business Integration (JBI) specification believe JBI can clarify the debate, and several open source ESB initiatives are embracing JBI.
The ObjectWeb Consortium recently announced the "Petals" project to develop an ObjectWeb JBI platform. The Petals services platform is designed to extend the ObjectWeb open source Celtix ESB initiative with a JBI container as a core element. The ServiceMix, JBoss Inc. and Mule open source ESBs also support JBI. The JBI spec (JSR 208) extends the Java 2 Platform, Enterprise Edition and Standard Edition (J2EE and J2SE) with business integration service provider interfaces (SPIs), allowing third-party components to interoperate.
"We see JBI as the basic requirement for creating an ESB," said Rafael Marins, director of Fossil E-Commerce, based in Brazil. Fossil is a co-lead of Petals, along with EBM WebSourcing, a business integration company in France. ObjectWeb's Petals project will be using the ObjectWeb Fractal component model and the Celtix ESB for the transportation layer. Marins said Petals will be available as a standalone, as well as with JOnAS, an open source implementation of J2EE.
"Our objective is to develop an ecosystem around ObjectWeb software components we believe are related to integration issues," said Christopher Ney, executive director of ObjectWeb. "The JBI architecture was at the center of what we wanted to do with our existing technology; this is how we got Petals going."
"JBI has got a lot of promise," said Carl Treiloff, director of product management at Iona, which contributed the Celtix code base to ObjectWeb. "The key thing is building a vibrant ecosystem for JBI over and above Celtix. The Petals work is a first step in the validation in that." However, he added, "Celtix will be more than JBI; Celtix is both an ESB and a framework."
According to Dave Chappell, vice president and chief technology evangelist at Sonic Software, "The Petals initiative marks another place where the proliferation of the concept of ESBs is happening in the open source community. It will further the adoption of JBI as well." Bedford, Mass.-based Sonic was a founding member of the JBI Expert Group.
At JavaOne earlier this year, Sonic demonstrated its JBI implementation, which will be built in to the next major release of the company's ESB. "When we first set out to create JBI over two years ago, we had a vision that one day JBI would help drive the shape of ESBs, much like the EJB spec drove the shape of application servers in the late '90s."
This movement bodes well for JBI, which failed to get the support of IBM and BEA Systems Inc., two of Java's biggest backers, when it came up for ratification earlier this summer.
"I feel strongly that this combination -- the 'perfect storm' -- of open source, ESB and JBI will really break the logjam of SOA," said Tom Miura, CEO of LogicBlaze Inc., Marina del Rey, Calif., a provider of business integration solutions based on open source technologies and a supporter of ServiceMix. LogicBlaze just announced a variety of technical services and support subscriptions for ServiceMix 2.0, which has just been released and is available under the Apache 2.0 open source license.
"JBI nails down standards, as far as a version 1 can be nailed down, and standards are what SOA will be all about," Miura said. "Standards bring choice for customers, so enterprises won't be locked into a particular vendor. You can pick a JBI container from us and use somebody else's BPEL engine; you plug it in and it will work."While JBI for the Java community makes sense, "for companies thinking about heterogeneous issues and building out an SOA to deal with those issues, JBI is not on the top of their list of technologies," said Jason Bloomberg, a senior analyst at ZapThink LLC, Waltham, Mass. "Because it's focused on Java integration, we see most of the conversation within the Java circle, not within heterogeneous SOA circles."
And exactly how the role of JBI and the role of ESBs fit together is another question, Bloomberg said. "The challenge the ESB market has is there is no one clear definition. The other big challenge is that most vendors are telling customers that to build SOA you need an ESB, which is not true. An ESB is neither necessary nor sufficient. And JBI is a Java approach to building an ESB. An ESB that supports JBI will be more interoperable in a Java environment, but it may or may not help with an SOA initiative."
In related news, Iona and ObjectWeb just announced that the Celtix project has completed Milestone 2, which makes available a complete and tested binary format of the core Celtix architecture. Milestone 2 includes implementation of the binding API and support for message handlers. Both features enable the Celtix core to support the use of plug-ins. Milestone 2 also expands SOAP 1.1 support to include DOC literal and RPC literal, as well as the ability to handle faults. APIs supporting JAX-WS Sync and One-Way have also been completed.