Is orchestration an ESB responsability?

Question

Hi there!

Is an Enterprise Service Bus (a tool that acts as a mediator, a message broker, a service enabler, schema transformation enhancer, transparent location provider, service aggregator, load balancer, monitor, and all that stuff) responsible to orchestrate services?

What about putting an automated business business process with more than thousand steps and dozens of service invocations inside you enterprise service bus?

Would you do it, or would you use a specialist in orchestration such as a BPEL engine?

Please gimme you opinion.

Answer 1

My short quick answer is NO, that not its responsability.

I would rather let that to the BPEL or a BPM suite.

Mhh I don't know what else to add :) ... Good luck?

Answer 2

Now my own vision.

Regarding all the work an ESB has to do, putting service orchestration inside the main infrastructure element of your SOA is not a good idea.

Aggregate, ok! But keeping your communication channel busy with business logic will, for sure, cause a terrible impact in the ability to delivery other features.

After all, most ESBs such as as BEA Aqualogic Service have a limited support for orchestration including lack of stateful capabilities, and activities like wait (a timer) or pick (wait for some input to move on the process), split/join capabilities (already added on ALSB 3.0), and so on.

No way. Just use tools like a BPEL engine or a tool like Weblogic Integration.

Thanks.

Answer 3

Yes and no. There's a thin, and sometimes indistinguishable line between orchestration and aggregation/service augmentation.

In general, if you've got any long-running or complex business process (process being the key word, although I'm going to avoid defining it) - that's best suited to BPEL.

Simple tasks, such as aggregating the results of three service calls, could and often should be done in an ESB layer.

It's not worth losing too much sleep over, though

Disclaimer: I am an IBM ESB consultant, although I'm not writing this in an official capacity.