We've been having a bit of an architectural discussion to choose the right technology to implement some web services and I would appreciate any thoughts any of you could have on it. I'll try and explain the scenario as thoroughly as possible and the reasons why we can't decide between the different options, but please do ask if anything isn't clear.
We are preparing a new web application for a retail environment, the application won't be accessed by final customers but by shop staff; shop staff will use both a standard PC and a tablet to access the web application.
Although most of the information needed by the web app is held centrally and hence it is accessible by the web server, some information is specific to the shop and is stored within other machines in the very shop itself, which means the web application needs some means of local communication. We don't want the central server to know the configuration of each individual shop and we want to avoid manual configuration in each shop, so we're seeking a way in which the web application can automatically find the necessary local services.
From here we thought of several options.
Web services are implemented in SOAP, which includes a discovery protocol that is handled by the wrapper app.
Web services are implemented in simpler RESTful (eg a URL get API), and a different technology is used for discovery protocol (like UPnP, also handled by wrapper app). This makes the web services simpler but adds the need of another technology.
Remove the wrapper application and discovery protocol and hard-code the IPs for the local services so these are known by the central web server. This may not render possible since we haven't got confirmation at this point that we can force the same hard-coded IPs in all shops, but assuming it is possible then the same two subtoptions appear.
Web services in SOAP, maybe a bit of an overkill since discovery is not needed now.
Web services in RESTful, easier to access from JS but again the potential CORS conflict.
I think that's pretty much it, thoughts and comments greatly appreciated.