Effects of adding new method to asmx web service

Question

We have a ASMX Web service 2.0 which was created way back and some of our applications still use it. Now we want to add another webmethod to it and I am not sure what effects it may cause with existing clients / apps. Or what precautions I should take while doing that.

I would appreciate your views.

Answer 1

Adding new methods should not cause any problems for the existing clients as long as the interface (signature, web service namespace) of the existing methods remains unchanged. Of course, existing clients cannot call the new methods, but the old ones should work as before.

Though adding methods works, there are explicit ways to version the interface of an ASMX web service. See this link for details.