[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: New PR Issue: RMD cannot detect some incomplete Sequences
Title: RMD cannot detect some incomplete Sequences
Description:
WS-RM 1.0 [1] defined a sub-element of the wsrm:Sequence header that served to mark the containing message as the last message in a Sequence. WS-RM 1.1 [2] has removed this element. Consequently the RMD has no guaranteed way of determining whether it has received all the messages in a Sequence. This presents obvious drawbacks to an Application Destination that may wish to know if it has received all the data that the Application Source sent it. In addition to this it makes correctly implementing the "incomplete sequence behavior" semantics impossible since the RMD cannot always determine what is and isn't an "incomplete Sequence".
For example, suppose an RMS creates a Sequence, sends messages 1-10, then sends a CloseSequence. Suppose that messages 9 and 10 get lost but the CloseSequence message is received by the RMD. The RMS can determine that the Sequence is incomplete (final ack is missing 9 and 10 from the range), but the RMD has no way of knowing, nor is there any way for it to discover, that the Sequence is incomplete. If the IncompleteSequenceBehavior was "DiscardEntireSequence" then the RMS will conclude that all of the messages will be discarded whereas the RMD will, in all likelihood, deliver all of the messages to the Application Destination under the assumption that the Sequence is complete.
Proposal:
Put the LastMessage element back in the Sequence element. Add additional wording around the definition of IncompleteSequenceBehavior stating that a Sequence without a message that was marked "last" is defined as incomplete.
References:
[1] http://specs.xmlsoap.org/ws/2005/02/rm/ws-reliablemessaging.pdf
[2] http://docs.oasis-open.org/ws-rx/wsrm/200608/wsrm-1.1-spec-cd-04.pdf
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]