RE: [ws-rx] Issue 129: Define "discard"

["Durand, Jacques R." <JDurand@us.fujitsu.com>]

Editorial comment:

 

as defined, “discard”  *exactly* means “not deliver” as far as the observable behavior of RM is concerned…. So this proposal should honestly use the term deliver already in the glossary instead of adding a redundant term actually defined as “discard: to not deliver”.

 

More substantial comment:

 

I can’t find in the archives the original motivation behind  wsrm:IncompleteSequenceBehavior , but for me it always had a non-normative value – a hint for the RMS about the RMD behavior that the RMS can use for optimization purpose.  

 

This proposal below by effectively conveying a delivery assurance commitment from RMD to RMS, goes far beyond, and the fact that the feature is optional does not change its nature. If we go that route, why not more generally convey in CSR the DA conditions this sequence will be submitted to on RMD side? (dup elimination or not, different flavors of ordering, …) I am not necessarily objecting to this, but IMO i129 is not the place to resolve this.

 

If the RMS wants to have some contractual assurance on the RMD delivery behavior, it can be obtained (a) either out-of-band like any other DA, (b) or in case this is too dynamic (subject to change with each sequence, based on resources, etc.) then the use of  IncompleteSequenceBehavior can be more formally bound to an out-of-scope agreement / policy.

 

Still, my RMD may want to send a hint on its general behavior so that the RMS can behave more efficiently, but it may not want to formally – or strictly - commit to this (unless again out-of-band agreement).

                                                                                                                                               

So I would keep it simple on the replacement of “discard” (either use “not deliver” or “not process further”) and remove the RFC2119 keywords… getting back to something close to the initial DougD proposal I believe…

 

Jacques

 

 

--------- Doug Davis wrote: ---------

/wsrm:CreateSequenceResponse/wsrm:IncompleteSequenceBehavior
This optional element, if present, specifies the behavior that the RM Destination will exhibit upon the closure, or termination, of an incomplete sequence. For the purposes of defining the values used, the term 'discard' refers to the RM Destination never allowing a particular message to be processed by the Application Destination.

A value of “DiscardEntireSequence” indicates that the entire Sequence MUST be discarded by the RM Destination if the Sequence is closed, or terminated, when there are one or more gaps in the final SequenceAcknowledgement.

A value of “DiscardFollowingFirstGap” indicates that the messages in the Sequence beyond the first gap MUST be discarded by the RM Destination if the Sequence is closed, or terminated, when there are one or more gaps in the final SequenceAcknowledgement.

The default value of “NoDiscard” indicates that no acknowledged messages in the Sequence will be discarded by the RM Destination.