What is SOA (Service Oriented Architecture)?

Question

Call me a troll if you want, but I\'m serious: how exactly is the new SOA trend any different than the client-service architecture that I was building 15 years ago?

Answer 1

Most of the answers here seems to convey that SOA (Service Oriented architecture) is about building application in a standardized manner so that other applications can interact with it in platform independent manner.

I am not sure if meaning has changed since but I have had an opportunity to work with a company that offers SOA suite and following are my thoughts on it.

Of course when you design an application you cannot guarantee it will be cross platform compliant. Take for example stock Trading systems. They use Fix protocol to transfer messages. Do you expect it now to return data in XML format so that it can be so called SOA compliant? Definitely not! SOA is an architectural approach that can help you decouple your application/services and let them interact with each other. Backbone of SOA is a ESB (Enterprise Service Bus) which is used to transfer data from one service to other. SOA architecture should take care of formats conversions. For example -

FIX(Service 1) -> (XML ---ESB---> XML) -> JSON (Service 2)

These conversion modules are commonly called as adapters and are generally part of SOA suite. For a bit more information refer to another answer -

Difference between SOA and ESB

Sure SOA is a word is hyped for marketing purpose. Technically speaking it as simple as de-serializing and serializing data so that services can be decoupled and platform independent but the idea behind it is concrete.

Also refer Wiki page for the same.