Question

Let’s say I have many web services (REST or normal HTTP request) and I want to define in which order they should be called. I want the order to be easily configured (through XML files) and return error responses in case they are called in the wrong way.

When I say tools I mean some framework in Java. The framework should have good documentation with examples.

I don’t want only a name but I would like pros/cons – why should I choose one or another.

EDIT: I forgot to mention it has to be an OpenSource (or any free licence for unlimited usage). And the application will probably run on GoogleAppEngine or Tomcat.

Answer 1

If you want to orchestrate long running processes then what you need is a BPEL engine.. if not you can go for an Enterprise Service Bus..

WSO2 ESB is an open source Enterprise Service Bus and WSO2 BPS is a business process server built on top of Apache ODE.

eBAY using WSO2 ESB to process 1 Billion messages per day.

Disclaimer: I am an architect from WSO2.