IBM, Microsoft team on reliability spec for Web services

IBM, Microsoft, BEA Systems and Tibco on Thursday released a pair of Web services specifications designed to answer questions about reliability that have been dogging the emerging technology.

IBM, Microsoft, BEA Systems and Tibco on Thursday released a pair of Web services specifications designed to answer questions about reliability that have been dogging the emerging technology.

The announcement comes just two weeks after the Organization for the Advancement of Structured Information Standards formed its Web Services – Reliable Messaging Technical Committee to work on an almost identical specification.

IBM, Microsoft and their partners ignored a March 11 deadline to join that effort, which is being led by Fujitsu, Hitachi, Oracle, NEC, Sonic Software and Sun.

Instead, IBM, Microsoft and their partners unveiled WS-ReliableMessaging, the same name used by OASIS, and WS-Addressing. The two protocols are designed to guarantee the delivery of messages between applications that may be separated by a number of intermediaries and distributed over a number of platforms. Each of the specifications is an extension to Simple Object Access Protocol (SOAP) and can be used over any transport technology, such as HTTP.

The lack of standard protocols for reliability, security, management and business process workflow are the major inhibitors to corporate adoption of Web services technology for integrating systems across corporations.

Microsoft and IBM’s work on reliability for Web services is a continuation of the pair’s push to develop industry standards to help enrich the platforms and tools they are developing to support Web services.

Last April, the pair, along with VeriSign, introduced WS-Security, which is now on a standards track at OASIS. Then in August, the duo along with BEA Systems unveiled a specification for business process workflow called Business Process Execution Language for Web Services (BPEL4WS), which has yet to be submitted to a standards body.

The pair’s reliable messaging work follows the same pattern of releasing a specification independently and soliciting feedback before turning it over to a standards body. IBM and Microsoft did not say when that might happen, but they took just two months to turn WS-Security over to OASIS.

The reliable messaging specifications, however, may overlap with work already underway at OASIS in its Web Services Reliable Messaging (WS-RM) technical committee. The scope of both specifications is almost identical.

“We’ve been working on this specification for well over a year, and it is designed to integrate with WS-Security,” says Steven VanRoekel, director of Web services marketing for Microsoft. “When the announcement came from OASIS, we were really close to being done and decided to stay the course.”

IBM and Microsoft also published a supporting white paper that gives an overview and roadmap for developing reliable messaging between Web services.

WS-ReliableMessaging from IBM/Microsoft shares the basic foundation of the OASIS work, which specifies three types of reliable delivery: guaranteed delivery, which means the message is delivered at least once; duplication elimination, which ensures the message is delivered at most once; and message delivery sequencing, which determines the order messages are delivered. The OASIS group, like IBM/Microsoft, also plans to integrate its specification with WS-Security.

But the IBM/Microsoft group is adding another level of functionality with WS-Addressing, which also includes input from BEA Systems. The intent is to ensure that messaging can be reliable across a number of platforms and systems not just between two endpoints.

“Microsoft and IBM are concerned with the fact that the other proposed reliability spec focuses too much on reliability between two endpoints on a point-to-point communications path. They feel that is too brittle and confining,” says Ron Schmelzer, an analyst with ZapThink.

With WS-Addressing, as messages wind their way from sender to receiver, perhaps across firewalls, gateways, multiple Web services and transport technologies, the protocol ensures that the sender and receiver are always known. WS-Addressing also can be used to specify how, when or if a system must acknowledge that a message has successfully made another hop across its intended path.

The specification also allows reliable messaging to be handled either at the application layer or in message-oriented middleware, such as IBM’s MQSeries.

The OASIS effort will address such complexities of reliable messaging but not in the first iteration, according to technical committee co-chair Tom Rutt.

“We want to create a simple and reliable spec and then build off of it,” says Rutt. “We still welcome IBM and Microsoft if they want to contribute.”

Rutt says the only stipulation is that any contributions must be done royalty-free, which is what IBM and Microsoft did with their WS-Security submission.

“I’m sad they didn’t join up initially,” says Rutt. “We have enough momentum to get a workable specification, and it would be nice if they get involved early in the process.”

The group’s first meeting is March 26, and it plans to have a final specification by September. IBM and Microsoft both missed the deadline for obtaining voting rights in the OASIS group and now need to attend a minimum of three meetings to gain that privilege.