Section 10.5. Strengths and Weaknesses


10.5. Strengths and Weaknesses

On the plus side, WS-Reliable Messaging offers the full range of quality of service that you would expect. The protocol is quite simple, but in many respects, it is far more efficient and effective than the other proposed specifications.

WS-Reliable Messaging has been carefully architected to be fully composeable with other Web services specifications that have been or have yet to be published by IBM, Microsoft, and their partners.

Specifically, WS-Reliable Messaging can be composed with WS-Addressing to enable a wide variety of reliable message exchange patterns (MEPs). However, WS-Reliable Messaging does not require composition with WS-Addressing or any specific version of WS-Addressing. For example, consider the case in which WS-Reliable Messaging is used with the synchronous SOAP/HTTP binding, such that the SequenceAcknowledgment is carried in a SOAP message on the HTTP response message. Typically, there would be no need to address information in this use case. Yet, it enables a far more robust and reliable exchange of messages between the sending and receiving endpoints. If a SequenceAcknowledgement message fails to reach the sending endpoint that initiated the HTTP request, the acknowledgement information is carried on the HTTP response for the next message in the Sequence without requiring that the sending endpoint resend the unacknowledged message.

WS-Reliable Messaging does not require specialized logic to validate required interdependencies between header elements that cannot be expressed in XML Schema, as do some of the other two proposed specifications that this chapter has reviewed. Therefore, off-the-shelf schema validators, such as the Apache Xerces parser, can validate the SOAP header elements.

WS-Reliable Messaging has also been carefully designed to be extensible. It can add optional extension element and attribute content from a foreign namespace in a manner that does not require implementations to be upgraded but allows those that do upgrade to take advantage of the extended features.



    Web Services Platform Architecture(c) SOAP, WSDL, WS-Policy, WS-Addressing, WS-BP[.  .. ] More
    Web Services Platform Architecture(c) SOAP, WSDL, WS-Policy, WS-Addressing, WS-BP[. .. ] More
    ISBN: N/A
    EAN: N/A
    Year: 2005
    Pages: 176

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