Early signs of the death of SOA?

Trying to follow what's going on in the world of enterprise
and web application architecture is guaranteed to make your head
spin. Much of the controversy centers around the SOA vs. REST
debate. Without going too far out on a limb myself, here's an
(imperfect and imprecise) summary of the debate:

SOA (Service-Oriented Architecture) generally means using SOAP
and the myriad related WS-* specifications. Interactions between
clients and servers are accomplished by using Web Services
standards including XML, SOAP, WSDL, and UDDI.

REST (Representational State Transfer) views the web as comprised
of resources, all identified by URLs. Referred to by some as
"ROA" (Resource-Oriented Architecture). REST is an architectural
style, based on standards such as HTTP, URL, HTML, XML, and MIME
types.

I like this quote from Stefan Tilkov that I found in a comment at
http://www.infoq.com/articles/sanjiva-rest-myths: "SOA as a
business concept can be implemented using WS-* or REST - both
(and many others) are valid strategies. Others view SOA and ROA
as alternatives, with WS-* being an implementation of SOA, and
RESTful HTTP an implementation of ROA. That view is valid as
well."

SOA advocates tend to argue that the SOAP/WS-* specifications
make it easy to build an interoperable, standards-compliant
service-oriented architecture, and that REST is just a bunch of
technologies, not an architecture.

REST advocates tend to argue that the richness of the full HTTP
specification itself gives us all we need to build robust web
applications, and that SOAP/WS-* is too "Enterprisey", too
complicated, designed to make the vendors rich, and just not
needed for many purposes.

Anyway, the main reason I decided to write this article was
because of a paper I came across, written by Nick Gall, a VP at
Gartner. Mr. Gall's paper was submitted in response to a call for
papers for a workshop held on 27-28 February 2007, organized by
the World Wide Web Consortium (W3C) on "Web of Services for
Enterprise Computing", the aim of which was "to gather interested
parties to discuss and provide recommendations to W3C regarding
the best approaches to facilitate the processing of business
transactions and interactions with systems that pre-date the Web,
and address the need to interconnect intranet and/or extranet
services using Web technologies."

Mr. Gall's paper states the problem as "Web Services based on
SOAP and WSDL are "Web" in name only. In fact, they are a
hostile overlay of the Web based on traditional enterprise
middleware architectural styles that has fallen far short of
expectations over the past decade." His solution summary is
stated as "The W3C should leave the work on standardizing the
WS-* middleware architecture to the middleware vendors and shift
its focus to standardizing aspects of Web architecture that make
it easier to apply to "application to application" scenarios."
His conclusion states "that the W3C should extricate itself from
further direct work on SOAP, WDSL, or any other WS-*
specifications and redirect its resources into evangelizing and
standardizing identifiers, formats, and protocols that exemplify
Web architectural principles. This includes educating enterprise
application architects how to design 'applications’ that are
'native’ web applications."

I'm not sure how the workshop went, or if anything much was
accomplished, but to me it is pretty amazing that a top
representative of the Gartner consulting firm is basically saying
SOA is wrong, and telling the W3C to get out of (run away from!)
the SOA debate.

I guess we'll have to just wait and see how this all turns out.
For now, I'm betting on REST.

More articles on the SOA vs. REST debate can be found at
http://www.infoq.com/REST;jsessionid=9E7BF20CB5812F0C56B0434A97A166E3

J.A.W.