ASP.Net sites - shared WCF services

Question

I have several web sites that share common functionality - for example, address verification. Is it common practice to have a central location where this address verification service resides and is references by all of my sites? - as opposed to having the same service on multiple sites.

Are there any downsides to having the service at a central location?

Answer 1

Is it common practice to have a central location where this address verification service resides and is references by all of my sites

Generally Yes. It is common to have a single location where all site point to get the same information.

Answer 2

I can think of about two downsides to keeping services in a central location (and they both almost argue for instead of against):

• Depending on the load, now all clients of the services will be affected if another client over-stresses the common service.
• If you have multiple services, it makes it more difficult to control visibility if you need some services exposed to the internet, and others to stay on the internal network.

Admittedly, both of these issues can be unlikely unless you are a huge operation. But I figured I'd put them out there to serve as counterpoints :-)