Re: SOA-Q: WSDL rules or sucks?
On his blog, Jimmy Nilson has started a series of post regarding SOAs. The posts take the form of questions, and the latest question is:
SOA-Q: WSDL rules or sucks?
Sometimes I get the feeling that many SOA-ers think that WSDL sucks, while at the same time others talk a lot about it as the holy grail. What’s the current state?
It’s both 
. There is a lot to say for WSDL, and I think I said most of it in my post here.
The good news is that a WSDL document gives you is a implementation-independent contract. A contract is useful, because it shows you what you can acccomplish with a webservice, and what sort of features it supports. Language-independence is important, because a Web Service can have clients in multiple programming languages.
The bad news is that WSDL and SOAP don’t make a nice couple. SOAP is a messaging protocol, while WSDL defines a more RPC-like model, where port types represent interfaces, operations represent methods, and ports can be seen as concrete implementations.
In conclusion, a WSDL may not be the best way to describe a Web service contract, but it’s the best we have right now. In my opinion, SSDL is a much better match with SOAP, but it’s not the standard (yet).
marten.gustafson » WSDL said,
April 2, 2006 @ 8:58
[…] Arjen Potsuma writes in his reply to Jimmy …a WSDL may not be the best way to describe a Web service contract, but it’s the best we have right now… For me, working at a company with a complete concept and, sort of, process for EAI projects, WDSL not that’s interesting from a contract point of view either since we have formal contracts. Our concept of a contract is also much broader than a simple WSDL, we govern things such as availability, security, performance etc. […]