MC reviewed F2F agenda. Agreed by group.
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Chairs: |
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Oracle | |
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Enigmatec | |
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W3C Staff Contacts |
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Attendees:
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Nortel Networks | |
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Novell | |
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Oracle Corporation | |
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SAP AG | |
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Sun Microsystems, Inc. | |
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Oracle Corporation |
Substitutes:
Glen Daniels, Sonic
Bijan Parsia, University of Maryland/Mind Lab
Raw IRC log at:: http://www.w3.org/2004/03/01-ws-chor-irc and http://www.w3.org/2004/03/02-ws-chor-irc
Scribes for the face to face were: Jeff Mischkinsky, Monica Martin, Nick Kavantzas, Greg Ritzinger
The following is a listof recent scribes (in order): Assaf Arkin, Tony Fletcher, David Burdett, Tony Fletcher, Monica Martin, Ugo Corda, Mayilraj Krishnan, Ravi Byakod , Martin Chapman, Steve Ross-Talbot, Monica Martin, Nick Kavantzas, Ed Peters, Anthony Fletcher, Jeff Michkinsky, Dinesh Shahane, Greg Ritzinger, Ed Peters, David Burdett,Ivana Trickovic, Ugo Corda, Assaf Arkin, Monica Martin, Carol McDonald, Nick Kavantzas, Tony Fletcher, Mayilraj Krishnan, Francis McCabe, Jeff Mischkinsky, David Burdett, John Dart, Monica Martin,Tony Fletcher, Jim Hendler, Kevin Liu, TonyFletcher, Jon Dart, DavidBurdett,Ed Peters, Greg Ritzinger, Monica Martin, Len Greski, Jean-JacquesDubray,Monica Martin, Mayilraj Krishnan, Francis McCabe, Michael Champion,AbbieBarbir, David Burdett, Jon Dart, Carol McDonald,Yaron Goland, Leon Greski,Ed Peters, Greg Ritzinger, Daniel Austin, PeterFurniss, Jim Hendler
Minutes of 3rd feb 04:
http://lists.w3.org/Archives/Member/member-ws-chor/2004Feb/att-0018/Notes_2004-02-10.htm
Approved by Group
Tony Fletcher's meeting of February 10, 2004 con call:
http://lists.w3.org/Archives/Member/member-ws-chor/2004Feb/att-0020/20040217-0.htm
Approved by Group
ACTION: chairs should also ask marco to see if his requirements are captured within the latest req-doc (0113, 0120, 0127, 0203, 0210, 0217, 0301) Closed
no activity. Amend action for chairs to send Marco requirements doc and ask if requirements covers his use case
NEW ACTION: Chairs to send Marco the rqeuirements document (once approved) and ask if his requirements are met.
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, 0217, 0301) NO PROGRESS.
SRT - banana calculus, current thinking will be posted to the list.
ACTION:SRT will update bugzilla entries to reflect exceptions/error discussion. (0127, 0203, 0210, 0217, 0301) NO PROGRESS.
ednpoint lang. definition, no progress
still no progress (depends on previous)
ACTION: Nick to define the features required of an intermediate end-point language (0113, 0120, 0127, 0203, 0210, 0217, 0301) NO PROGRESS.
ongoing
ACTION: Chairs to look into a far east meeting in sep/oct (0113, 0120, 0127, 0203, 0210, 0217, 0301) IN PROGRESS.
Sept F2F location - no progress (at this point)
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 Jan6th conf call) (0113, 0120, 0127, 0203, 0210, 0217, 0301) NO PROGRESS.
On this agenda and will attempt to close by end of meeting
ACTION: Chairs to raise a topic of Binding, Context etc. (0113, 0120, 0127, 0203, 0210, 0217, 0301) IN PROGRESS.
chairs to raise topic on binding (will address when reveiwing Model Overview)
ACTION: Chairs to schedule conference call to review requirements document (see above) (0127, 0203, 0210, 0217) DONE.
To be discussed at this meeting.
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, 0217) DONE
ACTION: Team to review the Model Overview prior to next meeting. (0127, 0203, 0210, 0217) DONE
On this agenda
It has been confirmed that the following are now members of the group as invited experts
Robin Milner (Univ of Cambridge), Kohei Honda (QMWC), Nobuko Yoshida (Imperial)
Interview with Robin (useful info): http://nick.dcs.qmul.ac.uk/~martinb/interviews/milner/
A presentation was submitted by the chairs of the bpel group:
http://lists.w3.org/Archives/Public/www-archive/2004Mar/att-0016/WSBPEL-Update.pdf
until last week ws-chor was not on radar for these groups
Frank McCabe has since been promoting interest in chor
SWSL is happy to move chor type thing discovered there to this group.
BPSS (Monica)
draft schema by April
draft spec out by June
ISO (Jeff M)
initiated web services study group under JTC1 (jtc1/wssg), meeting last week
most of discussion was on how various standards groups can get PAS status
next meeting sched. for June
SRT - how does ws-chor participate?
SRT - does ISO consume standards?
JM - ISO normally creates them.
MC - goal is to get rid of all TBDs, Notesand convert all Drafts to Candidates
http://lists.w3.org/Archives/Member/member-ws-chor/2004Feb/att-0022/req-files-02-23-04.zip
AB - WSDL 1.0 changed globally to WSDL 2.0
Abstract - approved
2.1 What is Web Services Choreography? - word-smithing
removed some redundency in paragraph 1
2.1 approved
2.2 How is a Choreography used?
paragraph 2 r/executable code skeleton/code skeleton/
paragraph 1 r/automatically guarantee conformance/validate conformance/
paragraph 2 r/Thus a choreography /For example, a choreography /
remove duplicate paragraph
paragraph 4 r/In such a scenario each hotel/For example, each hotel/
paragraph 4 r/police/validate
paragraph 4 r/contractual behavior/observable interactions/
p4 r/behavioral contract/breaches of the choreography/
SRT - suggests widening the scope of p5
to lock freedom and leak freedom (agreed after some discussion by the group)
p6 removed
2.2 approved
2.3 Conventions usediIn this document - some changes to conventions were made
minor edits
2.3 approved
3 Use Cases
3.1 Use Case Descriptions
D-UC-001 -Travel Agent
Requirements for variation 1, merge NOTE into req. 1
Variation 2 approved
Variation 3 approved with changes
NK - r/choreography engine/choreography participant
Monica: is reply part of our requirement?
Martin: no, it is just guidance
Monica: exceptions are really "business exceptions"
Martin: we should be consistent on the terms errors vs exceptions
mm2: An exception does not necessarily infer that the
choreography terminates. It may exhibit a different behavior.
mm2: When you speak of composition of choreographies (+1 choreographies), you will have the condition
of exceptions that occur, with error messages returned. Note this subtle difference
mm2: in the comment for Variation 2, where an exception can be a less traveled path. A decision
is made whether or not it is substantive or not (technically and at the business level,
with the latter outside of the scope of CDL). When a response is returned, or error
mm2:values raised, an evaluation occurs (i.e. an error).
mm2: See some simple definitions at: http://www.cs.pdx.edu/~apt/cs558/lecture4_4up.pdf,
and a good brief http://www.cs.wright.edu/~tkprasad/courses/cs480/L10Exception.pdf.
Mm2: This is what I posted on exceptions and errors 11 Nov 2003. Monica
Jeff: what is the difference between app and infrastructure errors? it looks to be the same
Jeff: how do we make a distinction?
Martin: infrastructure error is what predefined by the WS-CHOREO spec doc
Jeff: we MUST have one error "SYSTEM" type of error and then everything else is an error in the app
Monica: what is QOS (in 3.1.1.3.6)?
Steve: qos is reliable messaging (guaranteed delivery, ...)
The tool that is used by the participants provides model checking to ensure certain liveness properties can be maintained. By common agreement the participants working on the choreography decide that they want to enforce livelock and deadlock freedom as well as ensuring that the choreography is leak free. The tools provides the necessary static behavioural type checking to ensure that these properties are maintained. - SUGGESTION FROM STEVE
Martin: Use-case 001, 002 moved from Draft to Candidate motions passed
Section 4 CSF Analysis
Goals:
G-001 Approved
Monica: motion to remove G-002
Martin: this is a good CSF
motion to remove G-002 passed
G-003 to G-008 approved
Motion to remove G-009 passed
Motion to move the goals from draft to candidate passed
CSFs:
CSF-001 to 0013 Approved
Motion to remove CSF-014 passed
CSF-015 to 018 Approved
Motion to remove CSF-019 passed
Motion to move all CSFs from Draft to Candidate state passed
4.3 cross ref CSF to requirements
9 : YES, D-CR-4510
7 YES - D-CR_4202
Nick: 13 NO (1 new requirement to be added)
2 Yes,
3 is to be removed
4 is removed
5 yes
6 yes
8 yes
9 yes
10 yes D-CR-5001
11 yes
12 yes
13 is not there add need to discuss if there should be a new requirement
14 is yes
15 yes
16 is not there; we should discuss if there should be a new requirement
17 yes
18 is removed
19 is removed
Having uncovered some missing requirements, motion to delete section 4.3 passed
5.1
Motion to move section 5.1 CRs to Candidate state passed
Motion to delete the titles in section 5 passed
Motion to delete CR-2302 passed
Motion to delete CR-4201 passed
Motion to delete CR-4202 passed
Motion to delete CR-4290 passed
Motion to delete CR-4221 passed
4222 reworded to say it must be possible to pass partipant identification data
Motion to delete CR-4224 passed
Motion to delete CR-4225 passed
(Recess; Day 1)
(Resume; Day 2)
Review of requirements starting at ...4310
4311: Discuss levels of abstractions.
Trace to Use Case 1. Passed
4510: CDL MUST be able to describe conditional behavior. Passed
4511: (Daniels) What does this mean?
Change to reference 'externally observable behavior'.
(Daniels) What about visibility?
Must enable the description of this behavior.
(Kavantzas) Interactions is not the only thing you can do in choreography.
Passed
4512: Recommendation to delete.
(Robie) Does this have to be only defined in the choreography definition?
No.
Delete 4512 Passed
4513: Delete as duplicate (4223 specifies).
4514: CDL MUST.....
(Liu) Need clarification of what multi-party is.
(Chapman) Not saying that it breaks down to binaries.
Peer-to-peer
Passed
4610:
(Liu) How given by application?
(Barbir) Looping or recursion - decision made at different points
(Kavantzas) What is recursive? Be more specific.
(SRT) No use case here.
CDL MUST be possbile to refer to a choreography from within its description.
(see Use Case 2, section 3.1.2.2)
Change text: Needs to be able to reference....recursive behavior such as buyer-distributor-seller.
Passed with change
4611: Dynamic participation - role binding can vary.
Chapman: Don't want to be able to introduce a new role at runtime. ".....MUST be able to change bindings at runtime..."
Passed
4612: Liu: Relates to synchronization.
Kavantzas: Need to have a coordination protocol.
Chapman: Isn't this fork and joins?
Liu: Linking is a mechanism for synchronization between subchoreographies.
Passed
4613: Must support syntactic reuse.
passed
4614: Kavantzas: What is the use case?
Delete? Passed
All other requirements passed
Dicsussion of poprosed new requirements from the CSF analysis above plus from use case cross referencing:
New1. A CDL document MUST be amenable to the generation of implementation code and test cases.
Agreed
New2: A CDL MUST not have any business semantics.
Why must not a CDL have any business semantics? (BPSS is a CDL and does have some I would say - make this must not into a may not?
Daniels: Don't want to preclude framework for negotiations to occur.
SRT: Annotations could include business semantics.
Changed to: A CDL MUST be independent of business semantics.
Agreed
New3:A CDL SHOULD provide the ability to specify various levels of QoS.
Changed to: ...specify properties.
Agreed
New4:A CDL MUST be able to describe reference passing (to enable the car hire company to interact with the credit card company on behalf of the user).
Duplicate of 4222 so no need to add this one.
Agreed.
New5:A CDL MUST enable the demarcation of transactional boundaries (in order to define the collaboration boundaries in order to provide guidance on the underlying infrastructure required to implement the collaboration).
Change: tx boundaries to collaboration group.
Agreed
New6: A CDL MUST enable variable timeouts to model different interactions that have a different time-to-live. (For instance, each carrier may impose a different limitation on the lifetime of a pending reservation.).
Change: variable to expression of static and dynamic timeouts
Agreed
New7: A CDL MUST facilitate the demarcation of observable xactional behavior (in order to define collaboration boundaries and provide guidance to the underlying infrastructre (i.e. to recover, replay messages etc.).Scopes for collaboration groups).
Duplicate of new5 above so not added.
Agreed
New8: A CDL MUST support a mechanism that describes the concerete protocol to be used for interaction.
Changeto : .. enable the expression of concrete protocol….
Agreed
New9: A CDL MUST be able to determine which choreography the message belongs to.
Debate about correlation as a requirement or a mechanism.
Change to: …which collaboration group a message belongs to
Agreed.
Steve to go off and rebuild the cross references of use cases and CSFs to requirements.
Model Overview was adopted as a WD at Dec f2f
The ER like diagrams were re-drawn into UML:
We also have an editors draft of CDL synched with the model overview:
http://lists.w3.org/Archives/Public/www-archive/2004Mar/att-0002/cdl_v1_editors.pdf
Discussion of design centers/Big issues.
6 listed:
1 do web services have to be choreography aware?
2 state alignment
3 model partitions (abstract, portable, concrete)
4 tx boundaries vs. choreo scopes
5 Banana calculus (errors/faults/exceptions)
6 Coordination protocol
1 do web services have to be choreography aware?
Working assumption?: all the web services participating in a choreo do NOT have to be aware that they are participating in the choreo
That is the question.
kevin -- too strong to req
mm -- may be implications on the capabilities of the participating ws
glen - may be a choreo hdr that we define, but can't expect all participants to understand
mm - does this have to do with potential deff bet passive/active
DECISION: consensus -- all the web services participating in a choreo do NOT have to be aware that they are participating in the choreo
2. Model partitions: abstract, portable, concrete -- do we need all three types
Kevin -- what is the criteria to differentiate
continuum between defining the completely abstract def to a very concrete binding
kevin -- wsdl has abstract, binding, runtime
Elevator pitch:
Abstract -- defines msgs names, sequencing rules, roles, composition (c'est tout)
abstract -- on implication on types
Portable = Abstract + types -- WSDL types for roles, wsdl msg types for msg names
Abstract -- also condtion rules are condition names and/or raw text
Portable -- expression language
Concrete = Portable + endpoint references, WSDL binding
What is use case for each of these levels
Abstract -- no "binding" to WSDL -- define "reusable" choreo that can be applied in diff env -- e.g. buyer/seller and quote/receipt
glen -- argues against this level -- claims that WSDL is sufficiently abstract that the reusability comes from defining differnet WSDL bindings
glen - wsdl 2.0 contains an extensible MEP capability -- so can define arbitrary msg patterns
kevin -- e.g. if you don't think rosetta net pip's can be modeled by a pre-def WSDL 2.0 MEP, you can define your own
kevin - why is having this very high level description useful?
nick - e.g. there is an english description of a financial protocol, wouldn't it be useful to be able to capture that
kevin -- usually use a graphical UML like tool for that level
martin -- why is high level description useful to us?
nick -- because they have operational semantics define.
Martin -- here is a decision pt, foo, if it evaluates to true then do a, then do b -- don't need to know how foo is evaluated
kevin - real ? is who will use this in real world
mm - w3c definition of ws includes wsdl; if this is "just" technical level; then tends to agree with glen
martin -- i'm not ready to decide yet, isn't that useful
jeffm -- 2 levels are probably enough -- the abstract is sufficiently abstract to be almost useless in the real world
jeffm - should probably combine abs + port and then maybe refactor to move some of the port into concrete
glen -- premature to even establish this hierarchy/factoring
mm - agrees wsdl should be bound (I think I captured that correctly)
Glen thinks we should move on and discuss the things themselves, which will help to vet whether this diagram is useful
Glen - there is a spectrum of "abstractness" (nothing bound --> fully bound). But always wrt WSDL. We're not going have components of CDL that talk about non-WSDL "things"
DECISION: conensus -- Bound to WSDL. consequence: if Choreo finds a "lacking" in WSDL, it should communicate the requirement to WSD WG
kevin -- important to separate design time info from configuartion/runtime information
martin -- there's 2 ends -- we're not quite sure how to draw the lines, and even how many there should be
martin -- that will evolve
Decision: Concensus – There are two ends of the spectrum from abstract to concrete. The abstract must be wrt wsdl. It is too premature to define and label any dividing lines between the two ends.
steve has updated the tables that correlate reqs, use cases, CSFs
goal is to look at his work and review/approve it
remove 3.1.1.2 requirement number 2 because it is an application req
DECISION: remove 3.1.1.2 requirement number 2 because it is an application req
reviewing all the "blanks" to make sure we haven't left anything important out, adding charter contraint, etc.
DECISION: consensus -- bless the tables and put in the requirements document
NEW ACTION: requirements editors -- insert the tables into the docs (done at meeting)
Kevin -- has some concerns about the def of choreography in the req doc. Likes the def in the CDL doc better
Have already review and approved that section so Kevin will raise an issue.
DECISION: consensus -- approve the new reqs draft as WD and publish
NEW ACTION: req editors to send requirements doc to yves
NEW ACTION: yves to publish requirements doc
time schedule next f2f -- june in east coast -- 2 offers -- monica and greg in burlington/waltham MA
Discusion with W3C staff. Suggest we should meet earlier.
Change of plans -- next f2f will be sooner - May 11-13 Oracle Conference Center at Oracle HQ, Redwood City, CA
NEW ACTION: yves update the choreo web page to reflect the correct status of model overview as WD, which was done at last f2f in December i.e. it should be Published
Groups wants issues list on the public page
NEW ACTION: yves put link to choreo bugzilla issues on the public page
jeffm -- propose making the ed draft of CDL as WD and publish .
DECISION: consensus to make the ED draft a WD
NEW ACTION: editors to produce html of doc: http://lists.w3.org/Archives/Public/www-archive/2004Mar/att-0002/cdl_v1_editors.pdf
NEW ACTION: yves publish the (html) WD of model overview
NEW ACTION: yves add link to current editor's draft of CDL (will point to the WD for the moment)
NEW ACTION: SRT send email to public list reminding people how to handle comments and issues on the docs
NEW ACTION: kevin cast his comments in the form of issues and send to commenst list (public-ws-chor-comments@w3.org)
NEW ACTION: yves put reference to issues email address on public choreo page
(some remaining time so back to the big issues list)
3. state alignment
After breif discussion, it it appears that there may/is general agreement that CDL should deal with state alignment -- there may be issues on the specific details
NEW ACTION: chairs -- schedule "tying the bow" on state alignment on next conf call
4 tx boundaries vs. choreo scopes
nick - tx boundaries/bananas are related
Tony not in room so will wait till he is around.
NEW ACTION: chairs schedule tx boundaries discussion on "a conf call coming to your neighborhood soon" so that the issue can be closed, on way or another
5 Banana calculus (errors/faults/exceptions)
action item already in place to address this
6 Coordination protocol
Coord protocol will be a large and important discussion
NEW ACTION: chairs schedule coord protocol issue
nick -- notes we have a draft language, suggests that we take use case and and try coding it in CDL
greg volunteers to use the draft cdl langauge to define a choreography from use case 1 or 2 in the requrements document
NEW ACTION: greg to code up use case (from req doc) in CDL
NEW ACTION: Chairs to send Marco the rqeuirements document (once approved) and ask if his requirements are met.
NEW ACTION: req editors to send requirements doc to yves
NEW ACTION: yves to publish requirements doc
NEW ACTION: yves update the choreo web page to reflect the correct status of model overview as WD, which was done at last f2f in December i.e. it should be Published
NEW ACTION: yves put link to choreo bugzilla issues on the public page
NEW ACTION: editors to produce html of doc: http://lists.w3.org/Archives/Public/www-archive/2004Mar/att-0002/cdl_v1_editors.pdf
NEW ACTION: yves publish the (html) WD of model overview
NEW ACTION: yves add link to current editor's draft of CDL (will point to the WD for the moment)
NEW ACTION: SRT send email to public list reminding people how to handle comments and issues on the docs
NEW ACTION: kevin cast his comments in the form of issues and send to commenst list (public-ws-chor-comments@w3.org)
NEW ACTION: yves put reference to issues email address on public choreo page
NEW ACTION: chairs -- schedule "tying the bow" on state alignment on next conf call
NEW ACTION: chairs schedule tx boundaries discussion on "a conf call coming to your neighborhood soon" so that the issue can be closed, on way or another
NEW ACTION: chairs schedule coord protocol issue
NEW ACTION: greg to code up use case (from req doc) in CDL