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JOnAS
JOnAS is another leading open source, freely available J2EE application server. It has roots in a J2EE implementation built by Bull, a leading French IT and consulting firm. The implementation was open sourced and its development is now under the umbrella of the ObjectWeb consortium, the same folks who are involved with the JORAM project. The ObjectWeb consortium is a collaboration between Bull, the Research & Development Division of France Telecom and INRIA, and The French National Institute for Research in Computer Science and Control. Some superb research went into creating JOnAS, including advanced transaction handling and a nice persistence engine. The persistence engine is based on JORM/MEDOR, ObjectWeb’s persistence framework, and provides a fairly good, but not complete, subset of the CMP 2.1 specification. JORM/MEDOR has implicit database mapping as well as the ability to use other backing stores such as a file system. ObjectWeb has several advanced prototypes available that have research technology in them.
These aren’t ready for production use yet, but some of the stuff looks very interesting from a theoretical standpoint. JOnAS also offers many of the same optimizations as JBoss. Their Jeremie protocol, for example, optimizes local RMI calls similarly to the way JBoss does. Performance tests show the two running very close together. The big plus with JOnAS is that the container has proven vertical scalability and a very nice degradation of performance after it hits the peak of its scalability. The documentation available on the Web site is quite extensive and of very good quality; kudos to the ObjectWeb guys for tackling the one area that tends to receive the least attention in open source projects. When downloading JOnAS, you have to go through the drill of filling out a form with some contact information and a license agreement. It’s not a big deal, but it’s one more hoop to jump through. JOnAS is definitely worth checking out. Its characteristics are described in the following table.
