Gartner analyst Larry Perlstein tried to make sense of the plethora
of Web services standards for delegates at the research company's
Symposium/ITxpo conference in Florida.
Perlstein's analysis looked at the core low-level de facto set of
protocols for Web services, Soap, WSDL, and UDDI, as well as some
of the higher-end protocols that include Business Process Execution
Language for Web Services (BPEL4WS).
He also commented on the standards bodies involved in Web services,
the Web Services Interoperability Organization (WS-I), which is led
by Microsoft, IBM, BEA Systems and Liberty Alliance, and is
spearheaded by Sun Microsystems.
Soap received a strong positive rating - the highest mark Perlstein
handed out. He said its strengths include broad vendor support,
broad tool support and it is relatively easy to use.
However, Soap is still a specification and has a lot of security
holes and scalability issues. "The best thing about it is that it's
simple," Perlstein said. "Incompatible implementations are a
concern, although I suspect the market will weed that out."
He added that the growing complexity might raise concerns in the
future. But by 2007, Soap would be used in approximately 60% of all
new development projects, Perlstein predicted.
Perlstein gave WSDL, the specification for describing Web services,
a positive rating, notably for its broad vendor support and growing
tool support, as well as the fact that it is
implementation-independent. "It's a generic technology that sits on
top of whatever you happen to be using," he said.
WSDL's weaknesses included varying version support, complexity and
its status still as a specification. "We're seeing a little
fragmentation between the vendors, and what they're going to do
with it," Perlstein added.
UDDI received a grade of promising, the lowest mark of the three
low-level specifications, with Perlstein highlighting limited
adoption and tools support, as well as the fact that the
specification had not been submitted to the World Wide Web
Consortium for ratification.
"This is the one layer where people are most confused," he said,
adding that the hype far outweighed the reality of what can be done
with UDDI.
There are strengths to UDDI, however, including growing vendor
support, the recent move to the OASIS standards body, and advances
being made to the specification.
Gartner expects that when versions 4 and 5 of UDDI emerge, in 2004
and 2005, public use of UDDI will begin, while internal use is
beginning earlier and should continue to grow. "We don't see a good
alternative to it at the moment," Perlstein said.
Higher up the Web services stack, Perlstein gave BPEL4WS a
promising rating. Its strengths include the combination of
technologies it inherited when subsuming Microsoft's XLang and
IBM's Web Services Flow Language (WSFL) and the fact that it
standardises process logic and interaction.
"The biggest threat is that a single standard is just not
achievable. It might happen, but online in proprietary scenarios,"
Perlstein said.
In 2005, Gartner predicts that companies will be dealing with
multiple implementations.
Perlstein also graded the Liberty Alliance and WS-I, giving a
promising and positive mark, respectively.
"The war between Sun and Microsoft seems to be making progress. But
history has shown that rivalry doesn't end easily," Perlstein
said.
He ended by saying that companies should not wait for the final
standards before embarking on Web services projects.
"Don't sit around waiting for everything to be finalised. If you do
that, you'll be waiting forever," Perlstein said.