OASIS ebXML Messaging Services TC

Re: [ebxml-msg] Issue for your review

  • 1.  Re: [ebxml-msg] Issue for your review

    Posted 10-18-2002 22:30
    Hi Doug, Comments below: > What I was describing in an > earlier email is an indeterminate ordering of business and MSH signals or > responses in this case. The MSH MUST make the incoming message available to the > application prior to returning (via the HTTP 200 reply if using that transfer > protocol) an Acknowledgment message. The MSH has no control over how quickly > the application operates so business signals or responses may arrive at the > originating server before the Acknowledgement message. We could try to force > that MSH to prevent outgoing messages including a RefToMessageID pointing to the > one it's working on but we can't guarantee the same MSH will even be used for > the outgoing message or close all of the race conditions. True, the same issue can arise across the EbXML layer/Application layer boundary (referred to as the Message Service Interface (MSI) in the spec) as you describe... It would be unsafe for a client of the MSI to assume that a message has not been successfully delivered to a remote party because an ebXML layer Ack hasn't been indicated yet. If the MSI client was relying on the ebXML layer Ack to arrive before considering its message sent, how would it behave when in the (non-intuitive although possible) instance you describe where it receives a response to a request that it doesn't consider sent yet ??? > In both cases, we need to describe the issue so originating servers do not > depend upon particular orderings rather than increasing the complexity of the > receiving server to (slightly) lessen the chances for ordering to follow > less-than-obvious patterns. Agreed...what do you think of these statements? 1. The ebXML layer in an MSH should only rely on ebXML layer mechanisms to enforce reliability / message ordering. The ebXML layer should not make assumptions regarding ebXML message delivery success or failure based upon transport layer response codes. 2. An MSI client may leverage MSH ebXML reliability to make assumptions regarding business message delivery failure. However an MSI client should not rely on MSH ebXML layer state to assume the timing of successful business message delivery. ?? Best Regards, Dave Elliot XML Global Technologies