Re: [The 4 Waves of Web Services Standards] Re: WS-Em
Chiusano Joseph wrote: >I agree that it is quite easy and tempting to consider Web Services as >being represented by a single "block" of standards, but I believe it is >more useful to think of it in various "waves" (or phases), and to talk >about the success or failure of those waves. I assert that there are >current 4 "Web Services Waves" in sight - one of which is already behind >us (but still ongoing for future enhancements), and one of which we're >in the midst of now. These are: > >(1) Core Specifications > >- Your basic SOAP and WSDL, whose early versions are mature and >ubiquitous, and whose specification is still ongoing; > >- We have completed the initial "phase" of this Wave; > Perhaps so, but it's been more like a series of intersecting and competing ripples. The "mature and ubiquitous" SOAP and WSDL are still in an extraordinarily confused state after several years of development. After starting off down the path of rpc/enc in SOAP 1.1, which basically provided an XML representation for simple data object graphs, this approach has now effectively been dropped in favor of doc/lit, which uses a schema description of data and leaves the interpretation of that data (as objects or whatever) to the applications. However, WS-I Basic Profile apparently couldn't swing enough support to *only* support doc/lit, so we're left with the alternative of rpc/lit also a part of the profile (neither one required, both allowed). This is not currently used by much of anybody, but at least some implementations (JAX-RPC included) plan to add this just because it's allowed by the profile. Meanwhile, even such a basic (and necessary, for real-world services) feature as attachment handling is left without any single specification. We've got the Microsoft-proposed (but then dropped) SOAP with Attachments (SwA) standard as the basis of WS-I Attachments - but Microsoft doesn't support it, and AFAIK has no plans to do so. Then we've got the Microsoft-proposed (but then dropped) Direct Internet Message Encapsulation (DIME) proposal. This is supported by one Microsoft add-on, and by several other frameworks just so they can exchange attachments with Microsoft code, but AFAIK Microsoft has no plans to support it in the future. Instead we've got the spiffy new SOAP Message Transmission Optimization Mechanism (MTOM, http://www.w3.org/TR/2004/WD-soap12-mtom-20040209/) apparently based on yet another Microsoft proposal (http://www.gotdotnet.com/team/jeffsch/paswa/paswa61.html) that throws away all concepts of layering in favor of having everything as part of the Infoset and leaving it up to the transport to sort out how to send each component. Gee, that sounds like fun - layered protocols are such a 20th century concept, after all. Given the ongoing confusion and incompatibilities at the level of basics, it looks like Web services have a very long ways to go before the current "wave" of WS-* proposals really gain relevance. The one exception may be WS-Security, if it does get approved by OASIS and does get supported by all the players. Meanwhile, we've got yet another layer of hype being added to the top of the Web services heap with the latest "SOA" buzz acronym... Ah well, at least it looks like the market for Web services training isn't likely to dry up anytime soon. - Dennis -- Dennis M. Sosnoski Enterprise Java, XML, and Web Services Training and Consulting http://www.sosnoski.com Redmond, WA 425.885.7197
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