|Subject:||Web Services - EAI or B2B? (Was RE: [ebxml-cppa] BPSS to WSDL map ping)|
|From:||Cory Casanave (cor...@enterprise-component.com)|
|Date:||Mar 12, 2002 10:23:03 am|
I have to violently disagree! I also suspect most companies promoting web services would not like the "Only for EAI" box. Simple single-shot RPC is not sufficient for either role.
There is no reason the same architecture and technologies can't be used for B2B and EIA. There is no reason to have a fundamentally different architecture just because your business partner is not owned by the same shareholders. The interaction requirements between "Lincoln Continental" and "GM Engines" is not that different than between "Lincoln Continental" and "Delco". In fact, with the rapidity of acquisition and divestiture and outsourcing it is unwise to architect for things inside and outside differently. We have customers who want to use ebXML internally - should we show them the door?
We have found the "collaboration" style of modeling and deployment is very effective for both B2B and EAI. While there may be some relaxation of some constraints internally, that is not something you want to architect for - it is something you should handle in deployment.
I find the W3C characterization of a web service just fine. Realizing that the business requirements will move it in the directions ebXML has already started down; Asynchronous document interchange supporting long-lived collaborative processes.
In providing the specification framework for enterprise web services we should address the total picture, from B2B to EAI type of integration - down to where a process role is encapsulated in a single business unit. This kind of architectural integration has real and immediate benefit to the enterprise.
-----Original Message----- From: Jean-Jacques Dubray [SMTP:jj...@eigner.com] Sent: Tuesday, March 12, 2002 12:38 PM To: 'Patil, Sanjaykumar'; 'Cory Casanave'; 'Jean-Jacques Dubray'; 'bhaugen'; 'OASIS ebxml-cppa'; ebtw...@lists.ebtwg.org Subject: RE: [ebxml-cppa] BPSS to WSDL mapping
If only life was as simple as if you don't mention anything it is going to work just fine. Unfortunately there is reality and everybody should know by now that you don't cross company boundaries with the same technologies that you use to cross department boundaries. They are intrinsically orthogonal in their requirements, though you could establish a layering that reuse come common technology. It the common denominator the internet? Can you layer web-service B2B on top of web-service EAI? Who knows how it will end up playing.
-----Original Message----- From: Patil, Sanjaykumar [mailto:spa...@iona.com] Sent: Tuesday, March 12, 2002 12:16 PM To: Cory Casanave; Jean-Jacques Dubray; bhaugen; OASIS ebxml-cppa; ebtwg- bp...@lists.ebtwg.org Subject: RE: [ebxml-cppa] BPSS to WSDL mapping
The following is a (work-in-progress, I guess) definition from Web Services Architecture WG in w3c - "A web service is a software application or component identified by a URI, whose interfaces and binding are capable of being described by standard XML vocabularies and that supports direct interactions with other software applications or components through the exchange of information that is expressed in terms of an XML Infoset via internet-based protocols".
WSDL is not directly implied as the only service description language in the above definition. However, the above definition does not restrict (or suggest as best usage of) Web Services to intra-enterprise integration only. Rather the mention of "internet-based protocols" in the above definition can be perceived as suggesting Web Services technology applicable in solving Inter-enterprise integration problem.
thanks, Sanjay Patil
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-----Original Message----- From: Cory Casanave [mailto:cor...@enterprise-component.com] Sent: Tuesday, March 12, 2002 9:09 AM To: 'Jean-Jacques Dubray'; Cory Casanave; 'bhaugen'; 'OASIS ebxml-cppa'; ebtw...@lists.ebtwg.org Subject: RE: [ebxml-cppa] BPSS to WSDL mapping
I think it is counter-productive to try and position WSDL as only for "intra-enterprise integration", the problems addressed by WSDL and BPSS are the same - both apply inside and outside the enterprise - ebXML is "enterprise" web services. There is recognition that "web services" must encompass most of what is in BPSS. This is primarily a political problem on agreeing on the representation of the required semantics. On the other point we are in agreement. -Cory
-----Original Message----- From: Jean-Jacques Dubray [SMTP:jj...@eigner.com] Sent: Tuesday, March 12, 2002 11:39 AM To: 'Cory Casanave'; 'Jean-Jacques Dubray'; 'bhaugen'; 'OASIS ebxml-cppa'; ebtw...@lists.ebtwg.org Subject: RE: [ebxml-cppa] BPSS to WSDL mapping
I think we agree (and this is I thought what I was saying), at the moment the only thing you can do is produce a WSDL from a BPSS/CPP (not CPA) since WSDL is kind of unilateral. In the process you would loose quite a bit of information, but this is not the point. The other way around (WSDL to BPSS) is not really possible. I think this remains true even if you bring WSFL in the equation.
Note that I am not urging Web Service standards to come to the level of BPSS, on the contrary, I think they should focus on what they do best, intra-enterprise integration (note that I don't want to use the term EAI), and not be distracted by the minor details of B2B.
Jean-Jacques Dubray____________________ Chief Architect Eigner Precision Lifecycle Management 200 Fifth Avenue Waltham, MA 02451 Tel: 781-472-6317 Cell: 508-816-4518 email: jj...@eigner.com url: www.eigner.com
-----Original Message----- From: Cory Casanave [mailto:cor...@enterprise-component.com] Sent: Tuesday, March 12, 2002 11:24 AM To: 'Jean-Jacques Dubray'; 'bhaugen'; 'OASIS ebxml-cppa'; ebtwg- bp...@lists.ebtwg.org Subject: RE: [ebxml-cppa] BPSS to WSDL mapping
Jean-Jacques, Yes and no.
You can import WSDL into a BPSS specification, (note that you will loose the endpoint - these would have to go into the CPP). The WSDL
would, of course, not be as rich as a full BPSS but it does define a service that is equivalent to the WSDL. This "reverse engineering" is
adapting to existing systems (Yes, WSDL just became legacy!). It
useful as a starting point to create a more expressive BPSS.
And (Switching directions), while it is true that WSDL produced
would not have choreography (for example), so what! That is not
of WSDL. The BPSS semantics specify this so why reproduce it in
is low-level endpoint semantics. You say that we will get this when
WSFL - but BPSS is already filling that role, we don't need yet another way to say the same thing (We will probably get it anyway - so W3C can invent it :). You can produce WSDL+WSFL from a BPSS just like you can
We do mappings between lots of technologies, the idea is to map
high a level model as you can and produce the set of specifications,
whatever) that captures those semantics. You don't need to map to just one thing and you don't need every target to capture every semantic
the job of the higher level model). So the higher level model
considered a constraint on whatever is behind the WSDL (What we
If WSDL is someday extended to have the BPSS semantics, then we
BPSS. It is the semantics, not the representation that is
can map representations but can't invent semantics.
-----Original Message----- From: Jean-Jacques Dubray [SMTP:jj...@eigner.com] Sent: Tuesday, March 12, 2002 7:45 AM To: 'bhaugen'; 'OASIS ebxml-cppa'; ebtw...@lists.ebtwg.org Subject: RE: [ebxml-cppa] BPSS to WSDL mapping
WSDL does not have the appropriate semantics to map to BPSS as Bob Haugen explained in this email thread. However, you can
a number of operations that will support the BPSS protocol such
can run on top of a web service infrastructure. But again, the
WSDL specification created is not enough to map isomorphically
definition. Just by looking at the WSDL produced, you would
the ability to enforce a particular sequence of invocation (at least until WSFL is ready), and also lack the ability to unambiguously declare that you have reached a given business state when a particular operation is invoked.
Hope that helps.
-----Original Message----- From: bhaugen [mailto:link...@interaccess.com] Sent: Tuesday, March 12, 2002 7:28 AM To: OASIS ebxml-cppa; ebtw...@lists.ebtwg.org Subject: Re: [ebxml-cppa] BPSS to WSDL mapping
Some people have touched on this angle, but just to make it explicit: there is a big difference between one-shot messaging or RPC use cases for Web services on the one hand, and longer business conversations on the other.
Most of the Web services gurus I know of understand that there are problems with long conversations, although their solutions vary from replacing HTTP (Don Box) to an explicit model for long conversations that works over many mechanisms (ebXML).
One problem with long B2B conversations is business state alignment. For example, was that offer accepted or rejected? Was that order fulfilled correctly? Did you receive that payment? Is the claim settled? Etc.
So you are building a business protocol stack over the technical protocol stack. The business protocol stack starts with the business transactions (offer-acceptance, notify-confirm, etc.) and builds other business protocols like commitment- fulfillment and claim-settlement on top of them.
WSDL is a puny mechanism for the business conversation protocols.
BPSS is a good start in the correct direction, in my biased opinion.
P.S. I think the conversations apply to B2C as well as B2B - don't you want your order to be fulfilled? But the B2C people have worked out a set of patterns using standard HTTP methods that seem to be approaching defacto standard status.