- From: Srinivas Pandrangi <srinivas@ipedo.com>
- Date: Thu, 28 Feb 2002 14:54:47 -0800
- To: "Vinoski, Stephen" <steve.vinoski@iona.com>, "Joseph Hui" <jhui@digisle.net>
- Cc: <www-ws-arch@w3.org>
I like Steve's definition of a web service. It captures some of the most important aspects of a WS. My only concern is if it is too broad to be useful. If we turn the question around, is everything that qualifies as a web service according to this definition actually a web service? For example, a "hello world" cgi program can be a web service according to this definition. A couple of options to narrow this definition: I think emphasising the "component" aspect of web services can help narrow this definition further. I think the fact that web services lend themselves to aggregation/composition is an important aspect of web-services. Emphasisng the use of XML for communication would also differentiate web services from "any old services". I appreciate the fact that it is not easy to come up with a reasonably simple definition that is not too broad, not too narrow and fits in 50-100 words :) Thanks very much Steve/Mark/Joe et al., for the proposed definition. --Srinivas -----Original Message----- From: Vinoski, Stephen [mailto:steve.vinoski@iona.com] Sent: Thursday, February 28, 2002 2:03 PM To: Joseph Hui Cc: www-ws-arch@w3.org Subject: RE: Web Service Definition [Was "Some Thoughts ..."] And as I explained on the teleconference: discovery isn't a necessary part of the definition, because I can write a system where applications access web services via URIs and communicate with them via standard protocols, all without the aid of any discovery service such as UDDI or WS-Inspection. I have real-world proof of this: some of IONA's customers have web services in production right now and are not using a discovery service in their systems. As for description: the fact that XML-RPC has been around for several years now and has facilitated the creation of web services without the need for a description language ala WSDL should be proof enough that description is not a necessary part of the definition, either. On another note, in another email, you said: >WSP08 is necessary because the property to be described >and to be discovered differentiates the Web Service computing >model from other contenders, such as EDI, CORBA, ... Just wanted to correct you: CORBA allows services to be described and discovered. Description has always been a part of CORBA via its Interface Definition Language (IDL), and discovery occurs through standard services such as Naming (like telephone white pages) or a Trader (like telephone yellow pages). --steve > -----Original Message----- > From: Joseph Hui [mailto:jhui@digisle.net] > Sent: Thursday, February 28, 2002 4:45 PM > To: Vinoski, Stephen > Cc: www-ws-arch@w3.org > Subject: RE: Web Service Definition [Was "Some Thoughts ..."] > > > > -----Original Message----- > > From: Vinoski, Stephen [mailto:steve.vinoski@iona.com] > > Sent: Thursday, February 28, 2002 12:06 PM > > To: Joseph Hui > > Cc: www-ws-arch@w3.org > > Subject: RE: Web Service Definition [Was "Some Thoughts ..."] > > > > I still have to agree with Mark that you're defining > requirements, not > > creating a web services definition. I suggest again, as > Mark did, that > > we work from the one that he and I put together. Is there something > > wrong with it? Is ti missing something? > > Suffice to say my response to Mark the other day also applies here. > > Per discussion on WS Def during today's telconf, I believe D&D > ought to be in. > > Joe Hui > Exodus, a Cable & Wireless service > =============================================== > > > > --steve > > > > > -----Original Message----- > > > From: Joseph Hui [mailto:jhui@digisle.net] > > > Sent: Thursday, February 28, 2002 2:59 PM > > > To: www-ws-arch@w3.org > > > Subject: RE: Web Service Definition [Was "Some Thoughts ..."] > > > > > > > > > > From: "Anne Thomas Manes" <anne@manes.net> > > > [snip] > > > > > > Hi Anne, > > > > > > > I'm a bit averse to using the terms MUST NOT, SHOULD, and MAY. > > > > > > They were tided over from IETF. Their virtue in > standards discourse > > > lies in the technical vigor as defined in RFC 2119. They > do tend to > > > stiffen up sentences, to the detriment of their literary > appeal. :-( > > > > > > > I'm not sure > > > > that we should impose the constraint defined by WSP04. > > > > > > WSP04 slams a door (a door, not all doors) at those who have funny > > > ideas about hacking into a host via web services. It also takes > > > away a big rope (not all ropes, a rope nonetheless) that some > > > implementors/deployers may hang themselves by accident. > > > WSP04 pretty much conveys "web services have a property of being > > > hacker unfriendly." (BTW, "safe" could supplant "hacker > unfriendly" > > > with a leaning toward generality.) > > > > > > > I think it's useful > > > > to include WSP05, although I don't think it's an essential > > > aspect of what > > > > makes a web service a web service. I'm ambiguous about WSP06. > > > > > > WSP06 may be thought of as a clause of self-preservation (or > > > robustness > > > by agnosticism. ;-) > > > > > > > I think WSP07 goes into too much detail. > > > > > > Point well taken. Indeed we can do away with the embellishment -- > > > the last phrase of the first sentence and the parenthesized text, > > > unless others object. > > > > > > > I think WSP08 gets too much into architecture, > > > > and isn't an essential aspect of what makes a web service a > > > web service. > > > > > > WSP08 is about D&D, which differentiates the web service > > > model from the > > > rest. That is, D&D is one of the properties that WS are made of. > > > > > > [snip] > > > > One recommendation that I would make to Joseph's definition > > > is that we not > > > > call out any specific technologies (WSDL, UDDI, etc.) > in the core > > > > definition. Our architecture should provide > > recommendations on which > > > > technologies to use, not the definition. > > > > > > I can go along with not calling out specific > technologies, and also > > > to err on the side of generality (as opposed to specificity) if > > > that's the WG's consensus. As stated in a previous message, I'd > > > like to also reiterate my position that we should be as specific > > > as feasible. > > > > > > > I'd also prefer to use the more generic term "contract" > > > rather than "well > > > > defined input/output parameters". > > > > > > "Contract" can mean different things to different folks in WS. > > > Thus one has to be overtly conscious of the context when > "contract" > > > is invoked. Right off the bat, XLang comes to mind. > > > > > > Cheers, > > > > > > Joe Hui > > > Exodus, a Cable & Wireless service > > > > > > > > >
Received on Thursday, 28 February 2002 17:55:13 UTC