Day 8 - SCA invocation models

On Wednesday we covered custom selectors, the SCA invocation model and some exception, error handling and compensation in BPEL processes.

The four different SCA invocation models are:

• Synchronous. Pretty obvious.
• Asynchronous, one way. Fire and forget.
• Asynchronous, deferred response. Fire and poll for result.
• Asynchronous, callback. Fire and the engine will call your callback method with the result.

Then we did custom selectors. Although the tooling only supports time-based selectors at the moment the selectors can be altered for much more complex tasks. The selectors can be customized using Java and hence pretty much anything could be done to select which component to call. One thing we thought of was to call out to an external rule engine.