Is it advisable to build a web service over other web services?

Question

I've inherited this really weird codebase where they've built an external web service over a bunch of internal web services just to add authentication/authorization using WS-Security, WS-Encryption, et al. Less than a month into this engagement, I'm already feeling the pain of coupling volatile components through rigid WSDL, esp considering some of them use WCF and other choose to go WSDL first. Managing various versions of generated proxies and wrappers at various levels is a nightmare!

I'll admit the design is over-complicated and could have been much better, but my essentially:

• Would you ever build a web service just to provide a cross cutting concern over a bunch of services?
• Would this be better implemented as web service handlers?

and lastly...

• Would you categorize this under the Web Service Gateway pattern?

Answer 1

I have seen similar implementations if you are exposing the services to the outside world and if you need to tighten down the security..check this MSDN column..

Answer 2

I saw that very thing being built one year ago. I almost cried when the team took months to build 4 web services, 2 of which simply wrapped other internal ones, using WCF and some serious encryption. The only reason they wrapped the internal ones was to change the potential error numbers coming back.

So, would I ever intentionaly do that? Nope.

Would it be better implemented as almost anything else? yep.

Would I categorize it under the WTF pattern? absolutely.