WS Architecture Teleconference
4 December 2003

See also: IRC log




Chair: MikeC

Scribe: Gerald Edgar


Approval of Minutes

Scribe: Minutes for November 20 [1] and September 18 [2] were approved.

[1] http://lists.w3.org/Archives/Member/w3c-ws-arch/2003Dec/att-0002/arch-03-11-20-public.html

[2] http://lists.w3.org/Archives/Member/w3c-ws-arch/2003Dec/att-0000/arch-03-09-18.htm

Message Oriented Model

MikeC :follow up from last telecon. the idea was to get comments on the MOM (message oriented model) anyone with comment on this  can raise it now or get e-mail responses. Dealing with it now means we can complete this. No comments. Have there been changes since the last telecon?

Frank: There are  few changes- it has not been discussed yet.

Mike C: Review the MOM draft and make whatever comments you are going to make, so that we can make  changes. and complete it.

Hugo: Concerning the  message header - a message header may contain orchestration information. This is the only reference to orchestration, one can wonder what is orchestration information, and we do not provide that information. (from 24 October draft, it is not in this one) the latest URL is in the

Frank:  the latest version is available at the web site.

Mike C: There are comments and it is up to the person to make sure they have the latest version to comment on.  People print copies and mark them. The person making the  comments has to make sure the comment applies to the latest version, in case it has been changes. Intermediaries as being between the message model and service model.

Ugo:  things have been changed here, feedback was received from Mark Baker, and that was incorporated.


Frank:  the view of intermediaries is infrastructure oriented. the view of intermediaries in WSA is not consistent with the view within SOAP. the transportation of messages is not the same as processing messages.  Within message processing, processors can offload tasks to intermediaries. [you can] link intermediates with message processing.

Rodger:  a commercial hub forwarding messages to others.
Ugo: There is a reason to emphasize soap intermediaries. it uses examples of gateways.  [We are] focusing on SOAP since that has more applications.

??:  intermediaries are a way to get to the back-end. Soap-aware intermediaries, with a processing model "must understand" tag workflow or message exchange pattern the intermediate is a service in itself as part of another workflow.

Frank:  when discussed on the editors call - the definition of an intermediary  - an agent that processes a message. The message it emits is the same massage, even if modified.  One can see intermediaries as a poor mans orchestration.

Rodger:  How is this the same message?

MikeC:  using the example of encryption.  The messages bits are completely different (that is - encrypted) but the message is the same.

Ugo: use of a gateway as an endpoint, and the start of a second message. The message that comes out is the same - the essential  message.

the soap intermediary is richer - you can change anything. There are two kinds of changes - one changes only the header, the other changes anything.

Ugo:  I do not agree - no one agrees that you can change the SOAP body.

MikeC: in the WS-P working group intermediary was put in for encryption.

Rodger:  it is up the application to decide if the message is the same.

MikeC: Frank - do you have specific objections? Intermediaries [can be seen] as an amorphis blob.

Frank:  this is one of the aspects effecting the MOM. This effected the service model. we should revisit this later. About the message being the same - even in the case of a packet in a LAN - is there a guarantee that the messages delivered are the messages sent. [discussion about routers and other infrastructure components]  [WS] messages can be seen in the same way.

Rodger: It is still confusing there is not an absolute reality on this,

Frank:  it is a specialized service. it has an extra property - the messages emited are the same as the messages received.

MikeC: Intermediaries. are an amorphous concept.  a service intermediary.

Rodger:  a service intermediary - rather than something like a router.

Abbie:  we need to discuss this further

MikeC: we need to discuss this on the mailing list.

Service Oriented Model

MikeC:   Frank - can  you lead the service oriented model?

Frank: The main thing  in the Service Oriented Model to account for processing and intermediaries. for message oriented intermediaries, headers, bodies and structure of models. For service oriented model, a message is not processed in one swallow, but in parts, The soap concept is a processing model, associated with the requests and delivering the model.  It is not part of the service oriented model to do this requires a more sophisticated idea of service.

The idea of a service role: a service role is that part of a service, it takes a specific role in an overall services . The model now needs a bit of tidying up. However, there are implications which to have a choice - to adopt intermediaries as simplified choreography or composition.  When you separate roles you have to address the aggregate. The current model does not address that a service can be composed of other services.  The other thing about the service model is the policy. The relation between policy and a provider. The provider accepts the policy the service realizes or satisfies the policy if it abides by it. then we can relate what How was talking about policy and management. Chorography needs to fit in but we have not thought a lot about it yet..

MikeC:  we need to cover aggregation or composition - services can be composed and decomposed of services.

Frank: is an intermediary - at the service level>

MikeC: how do services relate to message?. services invoked by messages, where do we explain this.

> an entity requests the service

MikeC:  the link  between message model and the service model

Katia:  message and semantics issues

Frank:  you could have the same service available in several ways.

MikeC:  the basic idea of SOA is that you focus on messages not on services. What is going on with messages.  you have to address entities at both ends. SOA - the fanatical view, you do not care what happens at either end Descriptions, semantics and syntax. We are less certain on actions and goals.  Actions - semantic level actions.

Ho:  Some comments on the model - we need to emphasize what we do with the service model. We need to put constraints on interfaces.

Frank: that is a WSD constraint. The interface is whatever you need to do to invoke that service. [there are]  references in the interface. Discussion on RPC and Web Services.  RPC vs. document oriented processing. SOA as document oriented processing

Ho: to distinguish between RPC and SOA, the interfaces. This constraint ...

Frank: you can do anything in anything. you can not possible to constrain this [interfaces]. The other thing is the document-oriented view. Trying to find a clear and easy way to distinguish between document oriented and message oriented processing.

Ho:  you can do anything,

Frank: the issue is do we want to express constraints in the architecture to make policy choices?

Katia:  we cannot give enough guidelines. How to determine if it is compliant with the WSA? It is difficult. We are putting out a view.

Frank: we would have to be very specific.

Katia: the different parties do agree on the semantics and meanings.

Frank: in a pure sense an SOA is sufficiently different from other architectures. That you can not do RPC. the consequence of that is we are exploring what is a SOA.

Katia:  [asking] what is message based processing, what is document based processing.

Rodger: 80% or more of web services in place today are RPC

Frank: Microsoft and others are promoting document views. I have difficulty with reconciling strict message oriented architecture and a document centric architecture.

Ho:  the goal is perhaps too abstract. State is worse. Choreography is one approach about combination of services.

MikeC to summarize - we do not want to focus only on choreography, but on composition, on roles, or be composed with other services. we have touched on the relationship between the interface and the description and intermediaries the message and document view, procedural, or document 

Document Status

MikeC: are there changes you are doing Frank?

Frank: there is a new diagram
MikeC  to clarify intermediaries. can we resolve this?

Rodger  We need to discuss the boundary ideas.

MikeC: We need to review Ugo's section 3, as well as the service-oriented model.

Scribe: [Time ran out, meeting ended at Start + 1hr 40 min]

Summary of Action Items

[Thanks to David Booth!]

This is a consolidated list of action items currently pending:

[PENDING] ACTION: Abbie writing text on security threats and resolution for document. Due next Wed.

[PENDING] ACTION: Bijan to check if someone from U.Maryland has the resources to help WSA with OWL related work

[DONE] ACTION: Chair to schedule F2F Mon-Thu noon. Host confirms OK.

[PENDING] ACTION: Chair will schedule time to follow up on the question of whether we should do more run-time / processing model work

[DONE] ACTION: David and Roger to clarify step 3 of section "1.5.6 The Process of Engaging a Web Service" [DONE] ACTION: David will find new home for 3.4.3 Trust and Discovery & point to it from Discovery

[PENDING] ACTION: dbooth and zulah to compose a message to the WSD WG asking if two WSDL documents can reference the same service and therefore provide different views (or projections) of that same service

[PENDING] ACTION: dbooth to clarify term "service provider" and "service requestor" and expand glossary

[PENDING] ACTION: dbooth to look at security notes put on public list by Roger

[DONE] ACTION: DBooth to provide MikeC a list of WG members in good/bad standing

[PENDING] ACTION: DBooth to reference the list of standards from 3.15 WS technologies in the stakeholders section

[PENDING] ACTION: fgm to check collation order of concepts

[PENDING] ACTION: Frank to add discussion on policies to service model

[PENDING] ACTION: Frank to discuss Features vs Concepts with Massimo and Katia

[PENDING] ACTION: Frank to move the last two paragraphs of "1.6.3 SOA and REST architectures" to the Semantics stakeholder section

[PENDING] ACTION: Frank to move these next two paragraphs to the Semantics stakeholder section

[PENDING] ACTION: Frank to propose text around architectural approach to semantics (intermediary visibility issue)

[PENDING] ACTION: Frank to re-draft Concepts and decide on Features VS Concepts

[PENDING] ACTION: Frank to resolve policy for the service model Security -> Actuall this means "add discussion"

[PENDING] ACTION: Frank will discuss with others how to refactor SOM to incorporate intermediaries properly

[PENDING] ACTION: Hao to incorporate Roger's proposed definition for Message

[PENDING] ACTION: Hao to send a use case example to the list and ask for good use cases

[PENDING] ACTION: Hao to work with Hugo on getting Hao's CVS access set up

[PENDING] ACTION: Hugo to provide boiler-plate message verbiage about WG members who have been absent and will be removed from the WG membership list unless they take action

[DONE] ACTION: Hugo to review Massimo's OWL and resolve issues in the document that Massimo points out

[PENDING] ACTION: Hugo to talk to Daniel about Requirements document

[DONE] ACTION: Hugo will look into mechanics of inviting experts

[PENDING] ACTION: Katia to review latest Discovery text

[PENDING] ACTION: mchampion to follow up with eric what does he mean by "standard notation for Web Services contract" [DONE] ACTION: Mike C will contact Zulah to see if she wants to be an invited expert

[PENDING] ACTION: Mike to add and wordsmith text in 3.11 choreography

[PENDING] ACTION: MikeC to incorporate all the Action items we didn't talk about into the minutes.

[DROPPED] ACTION: Mike to initiate a discussion about section 1.5.5 The Role of Humans to resolve the difference of opinions [PENDING] ACTION: Mike to propose changes to WS Reliability section in stakeholders perspective

[PENDING] ACTION: MikeC to see that MTF notes get done.

[PENDING] ACTION: MikeC to add and wordsmith text in 3.11 choreography

[PENDING] ACTION: MikeC to check archives to find text we think we agreed to for message reliability & add it to the document [PENDING] ACTION: MikeC to check archives to find text we think we agreed to for message reliability and add to document [PENDING] ACTION: MikeC to look through section 1.7 Web Service Techologies ( http://dev.w3.org/cvsweb/%7Echeckout%7E/2002/ws/arch/wsa/wd-wsa-arch-review2.html#id2617682 ) for wording that was used in absence of a decision to use SOAP/WSDL

[PENDING] ACTION: MikeC to propose changes to WS Reliability section in stakeholders perspective

[PENDING] ACTION: MikeC to propose text to replace these next three paragraphs (and the diagram), to explain the difference between an SOA and a distributed system.

[PENDING] ACTION: MikeC to schedule discussion of Roger's proposed stakeholder's perspective for EDI users [PENDING] ACTION: MikeM to look at security notes put on public list by Roger

[PENDING] ACTION: PaulD to propose text on federation of registries

[PENDING] ACTION: (Who???) Refine correlation definition and verbiage to make it more clear how it relates to other concepts. [recorded in http://lists.w3.org/Archives/Member/w3c-ws-arch/2003Dec/att-0002/arch-03-11-20-public.html#item03 ]

[PENDING] ACTION: Roger to go through & ensure he's OK with the latest list of standards

[PENDING] ACTION: Roger to send feedback on overall reliability

[PENDING] ACTION: Ugo will draft statkeholders view of intermediaries

[PENDING] ACTION: Yin-Leng to propose a new WS manageability section in stakeholders section (due by beginning of December)

[PENDING] ACTION: Yin-Leng to Update section 2 discussion of management to be in synch with section 3

[PENDING] ACTION: Zulah to look through this section for wording that was used in absence of a decision to use SOAP/WSDL

Minutes formatted by Gerald Edgar
$Date: 2003/12/17 15:23:47 $