
Welcome Web Services Activity
by Edd Dumbill
January 30, 2002
This week the World Wide Web Consortium announced the formation of
a Web Services
Activity. Within the W3C, "Activity" is the name given to an
ongoing focus of development encompassing one or more Working
Groups. Until this time, the W3C's only participation in the web
services world was through the XML Protocol Working Group, which is
essentially tidying up SOAP.
Since the formation of the XML Protocol Working Group, several
companies followed the example of the SOAP team and joined together in
ad-hoc groupings to develop the complementary machinery needed to make
SOAP work with their programming environments. One technology devised
this way was the Web Services Description Language, WSDL, which has
become closely intertwined with the use of SOAP. There are pitfalls
with trying to standardize something that's brand new, and WSDL has
come in for some criticism,
in the same way as SOAP did. XML.com's own web services columnists recently made
a plea for a W3C Working Group to take on WSDL. With the
announcement of the new W3C Activity, they got their wish.
The Activity comprises three working groups: XML Protocol (transferred
from the XML Activity), Web
Services Description, and Web Services
Architecture. Additionally, there is a Coordination Group to
ensure coherence among the working groups. It is the Architecture
group which is the most interesting of these, as it embodies the
essential advantage of this development work taking place within the
W3C rather than elsewhere. The role of the Architecture group is,
unsurprisingly, to design the overall architecture of the clutch of
technologies that will constitute web services. According to its charter, the
group has the following goals:
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The architecture described must be modular: a set of
technologies will need to be described to address individual
functionalities identified by the architecture document.
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The set of technologies identified must be based on
XML.
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The Web services architecture will need to be cleanly
integrated in the Web architecture: Web services should be
addressable resources, results of operations which do not have
side-effects should be cacheable, etc.
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The architecture designed by the Working Group must be
platform independent, must not preclude any programming model nor
assume any particular mode of communication between
peers.
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Focus must be put on simplicity, modularity and
decentralization.
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The framework proposed must support the kind of
extensibility actually seen on the Web: disparity of document
formats and protocols used to communicate, mixing of XML
vocabularies using XML namespaces, development of solutions in a
distributed environment without a central authority, etc. In
particular, it must support distributed extensibility, without
third party agreement, where the communicating parties do not have
a priori knowledge of each other.
What is particularly welcome about these goals is their sympathy
with existing Web infrastructure. Often when new technologies are
devised independently they build on an ignorance of existing
standards, storing up trouble for the future as the technology becomes
adopted. The Web is an existing application and all new additions need
to recognize that. If the Architecture WG achieves its aims of Web
integration and distributed extensibility it will go a long way to
ensuring the continued openness and relative "un-brokenness" of the
Web: this is vital in an area that is such a playground for companies'
product strategies.
The move of the XML Protocol WG into a more defined area away
from the thrust of XML development is also
welcome. It may enable an increased focus at the W3C on issues of more
foundational importance in XML. The Protocol WG's ridiculously huge
membership of over eighty reflected more the urge among companies to
be associated with the latest trend than a desire to work on the
technology itself. Giving web services its own Activity helps
contextualize SOAP and friends, and together with the slump in the
economy, will hopefully put an end to the trend of stupidly inflated
working groups.
Share your views on the W3C's new Web Services Activity in our forum.
Post your comments
However keen the participants may be, standards take, by
implication of their definition, time to produce. When the issue at
hand is something so potentially far-reaching as web services, extra
care must be taken. The reasons that some companies are frustrated by
the "slow" development of W3C standards have more to do with marketing
and product concerns than technical ones. Hence this is another reason
why the W3C taking on web services is a good thing: an independent
rate-limiter that increases the probability of something useful
emerging from the other end of the process. For an example of how
things can go wrong, look at UDDI: an initiative more motivated by
marketing and corporate strategic concerns than technical ones, not
especially versed in the foundations of the Web, and something that
hasn't really produced anything of real use. At any rate, UDDI needs
to wait for SOAP and WSDL to be be finalized before it even has a
decent use-case.
Some may view the new Activity as a W3C land-grab. Early on in the
SOAP days it was thought that the IETF was a better place to pursue
such work. Nevertheless, right now the W3C is the only consortium in
town that seems to work in a way that both satisfies corporate
participants and is capable of producing something technically
credible. W3C is already working with IETF on SOAP and pledges in its
new activity statement to liase with groups such as ebXML and OMG.
In summary, the new W3C Web Services Activity is very welcome. Its
aims are laudable indeed: the big question is whether they can be
achieved. I dearly hope that in two years' time I can write that the
goals of simplicity, modularity, extensibility, and integration with
the Web's infrastructure have been attained.
You Know You Are ... When
I am reluctant to introduce any more gimmicks into the XML
community, considering the recent deluge of XML-related limericks and
haiku. However, I thought this worth sharing: Micah Dubinko, XML.com
contributor and XForms expert, has recently been deeply into the XML
developers' list XML-DEV. He came up with a list of "top ten signs
you're spending too much time on XML-DEV," featured below.
10. You start off your message with "In our last argument,
you said..."
9. Added text to quote ratio < 1/100
8. You actually read every message
7. You email your wife to say you're coming home early,
and start the subject line with "ANN:..."
6. Visions of angle brackets dance in your
head
5. Your sig refers to XML--in all four lines of it (sorry,
Simon!)
4. You've replied in the same thread 10 times--to make a
single point
3. You can no longer speak an entire sentence without the
word "semantics" in it somewhere
2. You've chosen sides on "RDF vs. Topic
Maps"
And the number one sign you've been spending too much time
on XML-DEV:
1. You don't need to read XML-Deviant every
Wednesday.
Fragments
Also in <taglines/>
XML 2004: After Declaring Victory, What's Next?
An Old New Thing
Moving On, But Not So Far
XML at Five
Whither Web Services?
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Readers will probably be familiar with tiresome unsolicited
emails from anonymous email accounts inviting them to check out
sordid and unsavory web sites. Indeed, it is said by some that the
operators of such licentious sites lead the way in Internet
technology. One XML vendor certainly seems to think so, as I found
when I recently received a breathless missive from a Hotmail
account. The writer, purporting to be an excited member of the
public, invited me to check out a "really ground breaking ...
solution to XML in an enterprise environment" they'd come across.
My correspondent lauded the product as "filling a huge gap in the
list of available XML applications." I won't embarrass the vendor
concerned in these pages but I hope, dear Bradley, you find a
career that suits you better than marketing.
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As if the language isn't being ruined enough by such
deplorable tendencies as using the word "enterprise" as an adjective,
XML acronym factories (otherwise known as standards organization
committees) are doing their best to further pollute our lexicon. The
fascination with affiliating with a cause through acronyms is as
strong as ever, with the emergent trope of "WS??" for anyone wanting
to attach to the web services bandwagon. Readers should not confuse
acronymity for activity, however, as demonstrated by an announcement
that reached me this week. OASIS happily announced that the first,
undoubtedly dynamic, action of the brand new OASIS WSCM TC was ... to
change its name to the OASIS WSIA TC. With so many of these
groups floating around, it can be dangerous to assume anyone really
cares.
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One of the more curious discoveries I made at the end of last
year is that not everyone involved with the development of W3C's XML
Query Language is terribly happy about it. I say curious, as the
impression I have of this group is of a focused activity likely to
lead to a sound technology. As yet, nobody has provided me with a
solid reason for their unhappiness, so one must assume the normal
machinations of consortium politics. It is most peculiar, however,
that at the upcoming W3C Technical
Plenary there is only one working group refusing observers --
something considered rather impolite at a plenary event -- XML
Query. They are clearly expecting a fight!