- From: Francis McCabe <fgm@fla.fujitsu.com>
- Date: Thu, 17 Jul 2003 10:30:22 -0700
- To: "Martin Chapman" <martin.chapman@oracle.com>
- Cc: "Steve Ross-Talbot" <steve@enigmatec.net>, "Champion, Mike" <Mike.Champion@SoftwareAG-USA.com>, <public-ws-chor@w3.org>
+1. Following the form of the WSA, we have agents that provide and request Web services. This is based on the intuition that a service is fundamentally about the potential for action, and that actors (computational and otherwise) are the entities that do the acting. Frank On Thursday, July 17, 2003, at 09:16 AM, Martin Chapman wrote: > > I think there is a fundamental terminology issue here that needs to be > cleared up. > An entity (avoiding any overloaded word) that sends a message to a web > service (and may expect a response depending on the wsdl) doesn not > iteslf > have to be a web service. This is the most fundamental building block. > Furthermore this interaction supports an MEP (in soap teminology) and > pattern (in wsd teminology). > Perosnllay if we can not describe these meps in a choreography > language we > have failed, and hence I do not think that mep choreogaprhy is any > different > from web service choreography. > > Martin. > > > >> -----Original Message----- >> From: public-ws-chor-request@w3.org >> [mailto:public-ws-chor-request@w3.org]On Behalf Of Steve Ross-Talbot >> Sent: Thursday, July 17, 2003 2:14 AM >> To: Champion, Mike >> Cc: public-ws-chor@w3.org >> Subject: Grounding Choreographies (the atoms) - WAS Simple >> Choreography >> composition suggestion >> >> >> >> At the considerable risk of adding further confusion to the >> discussion I would like to attempt to clarify what I said on the call >> with respect to the grounding of a choroegraphy. >> >> >> Here is how I see it: >> >> A "web service" choreography, as distinct from any other >> choreography, is grounded to a minimum of two web services instances. >> This may mean that the web services are the same web services but >> different instance or it may mean that they are distinct (personally I >> have a hard time seeing what they would be anything other than the >> latter) such that I can observe a communication between them. >> >> A communication is a minimum of a single message sent from one web >> service to another web service. > > > >> >> It may be the case that in receiving or indeed sending a message >> the >> sending web service and/or the receiving web service can be externally >> observed to change their behaviour. >> >> A "web service" choreography, as distinct from any other >> choreography, is based on externally observable behaviour where this >> behaviour is defined in terms of communications between web services >> and externally observed behavioral changes of a web service. >> >> For the avoidance of doubt, a Message Exchange Pattern (MEP) or any >> mechanism that describes communication between two parties can be said >> to be a choreography. But it cannot be said to be a "web service" >> choreography. >> >> >> Cheers >> >> Steve T >> >> >> On Wednesday, July 16, 2003, at 02:57 pm, Champion, Mike wrote: >> >>> >>> >>> >>>> -----Original Message----- >>>> From: Fletcher, Tony [mailto:Tony.Fletcher@choreology.com] >>>> Sent: Wednesday, July 16, 2003 9:12 AM >>>> To: public-ws-chor@w3.org >>>> Subject: FW: Simple Choreography composition suggestion >>>> >>> >>>> >>>> The point I disagree with is the notion that something is not a >>>> Choreography if somewhere, at some level it involves 'orchestration' >>>> within a single system. If we accept this notion / >>>> restriction it means >>>> that you can only have Choreographies involving exactly two parties >>>> where each party only plays a single role - we will not be >>>> able to have >>>> Choreographies with more than two parties / roles at all. >>> >>> That wasn't my intent, FWIW. All sorts of compositions and >>> decompositions >>> can occur within a "choreography," but IMHO only those that involve >>> the >>> globally visible shared state are in scope for the choreography >>> description >>> language we are developing. The discussion yesterday got me >>> re-thinking all >>> sorts of things ... if the fundamental unit of a "choreography" is a >>> Web >>> service invocation / MEP, then all sorts of implementation details of >>> the >>> service that involved "orchestrated" interactions behind the scenes >>> are >>> abstracted away, but if the fundamental unit is a message, then all >>> those >>> messages behind the scenes have to be accounted for somehow. I'm as >>> confused as anyone at this point. >>> >>> By all means let's make sure that we don't box ourselves into a >>> corner >>> based >>> on some preliminary guesses about what terms mean! >>> >>> >>> This email is confidential and may be protected by legal privilege. >>> If >>> you are not the intended recipient, please do not copy or disclose >>> its content but delete the email and contact the sender immediately. >>> Whilst we run antivirus software on all internet emails we are not >>> liable for any loss or damage. The recipient is advised to run their >>> own antivirus software. >>> >> >> This email is confidential and may be protected by legal >> privilege. If you are not the intended recipient, please do not >> copy or disclose its content but delete the email and contact >> the sender immediately. Whilst we run antivirus software on all >> internet emails we are not liable for any loss or damage. The >> recipient is advised to run their own antivirus software. >> >> >
Received on Thursday, 17 July 2003 13:31:22 UTC