W3C WS-Choreography group


Teleconference Notes for 10th February 2004



Tony Fletcher (Choreology), Mayilraj Krishnan (Cisco), David Burdett (Commerce One), Steve Ross-Talbot (Co-Chair - Enigmatec), Ravi Byakod (Intalio), Abbie Barbir (Nortel), Greg Ritzinger (Novell), Martin Chapman (Co-Chair - Oracle), Nickolas Kavantzas (Oracle), Kevin Liu (SAP), Ugo Corda (SeeBeyond), Monica Martin (Sun), Dinesh Shahane (Tibco), Yves Lafon (W3C staff)


Scribe: David Burdett scribed on IRC but these notes were unfortunately not saved.   These notes from Tony Fletcher.


Approve minutes

The notes of the teleconference held 3rd January 2004 were approved.


Actions Item Review


ACTION: chairs should also ask marco to see if his requirements are captured within the latest req-doc (0113, 0120, 0127, 0203, 0210)   CLOSE.

The Requirements document was still not available and is currently with Daniel.  The Chairs decided to close this action.


ACTION: SRT and MM will provide further detail on the “banana-calculus” discussions in order to record this exception/errors discussion properly.  (0127, 0203, 0210).   IN PROGRESS

Steve has started the summary based on pi-calculus concerning exceptions and time-outs which he will share with Monica.  Steve hopes to send to the list by the end of this week.  Monica will attempt to contribute from the business semantics point of view while Steve from the modelling point of view.


ACTION: SRT will update bugzilla entries to reflect exceptions/error discussion. (0127, 0203, 0210)   NO PROGRESS.

Agreed to do when the action above is done (second action of this list).


ACTION: Nick to define the features required of an intermediate end-point language (0113, 0120, 0127, 0203, 0210)    NO PROGRESS.

No progress awaiting model review.


ACTION: convert ER diagrams into UML class diagrams (0113, 0120, 0127, 0203, 0210)   COMPLETED DURING THE MEETING.

Greg said that the UML diagrams are now available and just needed to be sent out (and during the meeting Greg mailed them to David Burdett who was able to convert to PDF format and send out by the end of a meeting).


ACTION: editors to revise documents and table of contents according to comments received (0203, 0210)   DONE

No comments have been received on a proposed set of specification documents and their table of contents so this action was marked as done.


ACTION: Chairs to look into a Far East meeting in Sep/Oct (0113, 0120, 0127, 0203, 0210) IN PROGRESS.

No replies have been received yet from members resident in the Far East and so Yves was asked to look into the availability of W3C facilities in Japan or maybe Australia for the September/October time frame.


ACTION: Chairs to organise an issues conference call in which the regular conf call is used with members to look at the issue in bugzilla (possibly the Jan 6th conf call) (0113, 0120, 0127, 0203, 0210)   IN PROGRESS.

Pending Requirements document availability.


ACTION: Chairs to raise a topic of Binding, Context etc. (0113, 0120, 0127, 0203, 0210)    IN PROGRESS.

Discuss today or next week (Not discussed on this call so next week)


ACTION: Editors to issue requirements document for review on public mailing list for next call (0127, 0203, 0210)   IN PROGRESS.

The requirements document is still not available.


ACTION: Chairs to schedule conference call to review requirements document (see above) (0127, 0203, 0210) NO PROGRESS.

The Requirements document is still not available.


ACTION: Steve/Martin - let us see some email traffic to manage the process to get the requirements doc reviewed quickly and published -if we cannot make it by 13th (which is tight) then we inform the members as such. (0106, 0113, 0120, 0127, 0203, 0210) DEPENDENT ON REQ DOC REVIEW (see above)


ACTION: Steve to ask WSD WG whether they intend to support publish/subscribe MEP. (0120, 0127, 0203, 0210)   IN PROGRESS.

Steve has asked the Web Services description group if they support a publish/subscribed MEP, and is now awaiting a reply.


ACTION: Team to review the Model Overview prior to next meeting. (0127, 0203, 0210)   IN PROGRESS.

Comments on the review on the model overview are invited though several folk are awaiting the UML diagram(s).


NEW ACTION:  Greg to log  the number of levels defined in the language specification and their definition as an issue. (0203) – DONE


ACTION: Greg to log Monica's issues into Bugzilla. (0203, 0210)   IN PROGRESS



Tracking items


The requirements document is currently with Daniel (Austin) for completion for this round.  (Tony: Subsequent to the meeting Abbie has sent a version to the mailing list.)



They have been no further issues raised pending the new Requirements document


Specification editors’ report

Model overview


David is working on a better exposition of the differences between the suggested levels of abstract, portable, concrete.


Monica raised the issue of the dependencies on other specifications in section 3.5.


David and Tony agreed the need for the abstract level (a declarative level that effectively gives the requirements on the infrastructure, but does not spell out the precise how) and also the need to specify the exact protocols and other specifications used.  However, there is a continuing debate about the number of levels required and their precise definition.


There was a brief discussion on how to include transactions in a choreography description, but it was agreed to tackle this subject properly on the next teleconference. Tony said that he was concerned that tying transactions to the choreography units (sub-choreographies) may work, but not lead to the most natural way of designing, choreography descriptions.  The point is that one needs to be able to design the units of the choreography and the overall choreography from the perspective of what the business process is attempting to achieve, and then decide separately which interactions need to be grouped into transactions. 


State Alignment

State is changed by message exchange.  David made the point that two roles that communicate with each other will not have the same state, but should be kept in compatible states.  For instance a buyer communicating with a seller.


This raised the question of state of what?  Tony suggested that what David had said was true in terms of the states of the communicating protocol at machines.  However there was at least one other type of state of concern to a choreography and that is the state of resources (e.g. an order ‘object’ itself) or the variables.  (Note a ‘Business Object’, such as an order can have state in terms of where in its life cycle it is – created, placed, accepted, fulfilled paid, rejected are some possible states that an order could have – no agreement yet on actual states there names or the allowed transitions between states.  It also has state in terms of the values of its content – originator address, items ordered, quantities, prices and so on.)  These can be in alignment at both sides of a conversation, or out of alignment.


Tony made the point that it requires an agreement protocol, such as a transaction protocol to give assurance that both ends of a conversation have a common view of the state of the resources of concern in that ‘conversation’.


As we ran out time it was agreed to carry the discussion on via the mailing list.


Any Other Business

As there was no other business and we were out of time the meeting was closed.

(I actually think there was one of item of other business raised but can not remember what it was - Tony)


Next meetings

Next Tuesday (17 February 2004).  The next face-to-face meeting of the group is as part of the W3C Technical Plenary Cannes – Mandelieu, France 1 – 5 March 2004 with the WS-Choreography group meeting on the Monday and Tuesday (1 -2 March 04.