Update 2005-04-19: "OASIS TC to Finalize WS-ReliableMessaging and WS-RM Policy Assertion Specifications."

[February 18, 2005] BEA Systems, IBM, Microsoft, and TIBCO have released a revised version of the WS-ReliableMessaging specification, updating the previous publication of March 2004. WS-RM is now published as two separate specifications: one for the core protocol elements and one for the related policy assertion. The new Web Services Reliable Messaging Policy Assertion (WS-RM Policy) specification refactors the Reliable Messaging policy assertion into a discrete specification. An initial public version of WS-ReliableMessaging was published in March 2003.

According to the revised document abstract, the WS-ReliableMessaging specification "describes a protocol that allows messages to be delivered reliably between distributed applications in the presence of software component, system, or network failures. The protocol is described in this specification in a transport-independent manner allowing it to be implemented using different network technologies. To support interoperable Web services, a SOAP binding is defined within this specification. The protocol defined in this specification depends upon other Web services specifications for the identification of service endpoint addresses and policies."

WS-ReliableMessaging belongs to the WS-* composable architecture being defined by Microsoft, IBM, BEA, SAP, Sun, and other industry partners. "By using the SOAP and WSDL extensibility model, SOAP-based and WSDL-based specifications are designed to be composed with each other to define a rich Web services environment. As such, WS-ReliableMessaging by itself does not define all the features required for a complete messaging solution. WS-ReliableMessaging is a building block that is used in conjunction with other specifications and application-specific protocols to accommodate a wide variety of protocols related to the operation of distributed Web services."

The copyright notice on the revised WS-ReliableMessaging specification now reads, in part: "BEA Systems, IBM, Microsoft and TIBCO Software (collectively, the 'Authors') each agree to grant you a license, under royalty-free and otherwise reasonable, nondiscriminatory terms and conditions, to their respective essential patent claims that they deem necessary to implement the Specification."

An introduction to the revised specification by co-editor Christopher Ferris (IBM) reports that in terms of technical content in the specification "the protocol has really not changed all that much. Most of the changes were motivated by feedback from participation and discussion at the Interoperability Workshop and follow-up in subsequent endpoint testing. These changes have led to a much improved specification. Most of the changes relate to the manner in which an RM Sequence is created." A summary of the May 2004 Interop Workshop is provided below.

The Reliable Messaging Model "is basically unchanged with one exception: the CreateSequence handshake exchange and the TerminateSequence message are now required as opposed to optional. The authors made this change to ensure that the protocol enabled efficient resource reclamation on the part of the RM Destination for terminated RM Sequences. Because the RM Destination assigns the Sequence identifier, once the Sequence has been terminated, the RM Destination can purge all state associated with the terminated Sequence. Further, the RM Destination can safely discard any messages received which contain a Sequence identifier for which it has no knowledge as these messages either belong to a terminated Sequence or belong to an invalid Sequence."

The new Web Services Reliable Messaging Policy Assertion (WS-RM Policy) specification "describes a domain-specific policy assertion for WS-ReliableMessaging that that can be specified within a policy alternative as defined in WS-Policy Framework.

The WS-Policy Framework and WS-Policy Attachment specifications "collectively define a framework, model and grammar for expressing the requirements, and general characteristics of entities in an XML Web services-based system. To enable an RM Destination and an RM Source to describe their requirements for a given Sequence, this WS-RM Policy specification defines a single RM policy assertion that leverages the WS-Policy framework."

Bibliographic Information

• Web Services Reliable Messaging Protocol (WS-ReliableMessaging). February 2005. Edited by Christopher Ferris (IBM) and David Langworthy (Microsoft). 37 pages. Copyright (c) 2002-2005 BEA Systems, IBM, Microsoft Corporation, Inc, and TIBCO Software Inc. All rights reserved. XML namespace URI: http://schemas.xmlsoap.org/ws/2005/02/rm.

  Authors: Ruslan Bilorusets (BEA), Don Box (Microsoft), Luis Felipe Cabrera (Microsoft), Doug Davis (IBM), Donald Ferguson (IBM), Christopher Ferris (IBM, Editor), Tom Freund (IBM), Mary Ann Hondo (IBM), John Ibbotson (IBM), Lei Jin (BEA), Chris Kaler (Microsoft), David Langworthy (Microsoft, Editor) Amelia Lewis (TIBCO Software), Rodney Limprecht (Microsoft), Steve Lucco (Microsoft), Don Mullen (TIBCO Software), Anthony Nadalin (IBM), Mark Nottingham (BEA), David Orchard (BEA), Jamie Roots (IBM), Shivajee Samdarshi (TIBCO Software), John Shewchuk (Microsoft), and Tony Storey (IBM).

• Web Services Reliable Messaging Policy Assertion (WS-RM Policy). February 2005. Edited by Stefan Batres (Microsoft) and Christopher Ferris (IBM). 11 pages. Copyright (c) 2002-2005 BEA Systems, IBM, Microsoft Corporation, Inc, and TIBCO Software Inc. All rights reserved. XML namespace URI: http://schemas.xmlsoap.org/ws/2005/02/rm/policy.

  Authors: Stefan Batres (Microsoft, Editor) Ruslan Bilorusets (BEA), Don Box (Microsoft), Luis Felipe Cabrera (Microsoft), Derek Collison (TIBCO Software), Donald Ferguson (IBM), Christopher Ferris (IBM, Editor), Tom Freund (IBM), Mary Ann Hondo (IBM), John Ibbotson (IBM), Lei Jin (BEA), Chris Kaler (Microsoft), David Langworthy (Microsoft), Amelia Lewis (TIBCO Software), Rodney Limprecht (Microsoft), Steve Lucco (Microsoft), Don Mullen (TIBCO Software), Anthony Nadalin (IBM), Mark Nottingham (BEA), David Orchard (BEA), Shivajee Samdarshi (TIBCO Software), John Shewchuk (Microsoft), Tony Storey (IBM).

Notes from the WS-ReliableMessaging Interoperability Workshop

"The authors of the WS-ReliableMessaging (WS-RM) specification, IBM, Microsoft, TIBCO, and BEA hosted a 2-day interoperability workshop at the BEA office in San Francisco, CA on May 12-13, 2004. This participant-led event focused on giving developers who were implementing the WS-RM specification a chance to test their code with other companies' implementations..."

The event was a resounding success on several levels, including:

• The extent of interoperability achieved met the goals laid-out
• The event generated feedback for the specification authors to use in other implementations
• Feedback focused mainly on the clarifications of minor issues rather than flaws in the basic design of the specification, which enabled greater productivity

As with previous workshops, the event was open to anyone who wanted to participate and had an implementation profile based on the WS-RM specification. The event included a set of scenarios that were used as the basis for the interoperability..." [from the report]