I was at the Integration Consortium (IC) European seminar in Brussels yesterday, and saw a fascinating presentation from Wells Fargo Bank that introduced me to the concept of insidious WSDL.
Among many interesting points that came out of the presentation was a reference to the problems that WSDL and its use was having at the major bank.
Apparently, Wells Fargo is one of the most advanced SOA users in the world, running many millions of SOA services every month. The architecture has been built up over a number of years, and WSDL has become the standard way to describe services – that is, the interfaces and what they do. However, an interesting phenomenon is starting to make itself felt. The service developers look at the rich WSDL language, and take the view that using it is quite sufficient to make the service is understandable and usable by other users and departments. Where they would previously have communicated to others to explain details of the service and how it works, they now feel that WSDL has replaced this requirement. The result is that communications is falling away, causing problems.
The problem is that just knowing the specifications of a service do not give a full semantic understanding of the nature and characteristics of the service, and special factors to consider in its usage. But with the crutch of WSDL to lean on, service developers think their job is done once the WSDL is created. WSDL is exerting an insidious influence that is slowly impacting internal communications to a greater and greater degree, with potentially damaging effect.
I guess the message is simple – WSDL is fine as a mechanism for specifying services, but do not let its influence replace the ongoing need for clear communications.