I was asked yesterday by a new customer about the following problem.
You have 2 systems that do basically the same thing. You build a new UI that needs to activate both systems. One system exposes WSDL A, the other – WSDL B. There is an ESB in the middle.
So, my gut feeling was – build a bridge in the ESB and make one service to the outside application.
But – turns out the bridge is quite a task. WSDL A and WSDL B were designed in a totally different manner – one is coarse grained and on is fine grained. So the bridge would need to store temporary information in a database. If that’s not enough – some messages contain JPG files, and processing and merging them is neccessary.
So, what do we do? we thought of another option. Building the new UI, and letting the UI activate the 2 services – or even better, do some mashups from the existing 2 applications (each accessing the different application).
Since this was just an introduction meeting, nothing was yet decided. My gut feeling is the bridge, since this is the organization first real “Service”, and I want to make sure the organization get the real taste for SOA.
But, there will be some more meetings on this matter – I will write updates on this post.