Overlord CDL 1.0-MR2 thoughts

[jeff.yuchang]

Well, I am thinking about whether use jPDL or BPEL for our target platform for MR2 release.

Firstly, let me quote some concerns from Gary Brown's email.

'objectiser' wrote:

I have had a brief look at jPDL recently to start thinking about how we could tackle this one next, but from an initial investigation, cannot see where 'send' and 'receive' actions are encoded. At the most generic level it appears as everything is a node or task - requiring custom node implementations (action handlers I think) to do specific activities. The closest I found to what we would need is the integration with JBossESB, but this is JBossESB specific - it would not help if (for example) the jPDL was sending or receiving messages via JMS directly.

Also the JBossESB integration is only at the level of service category/name - it does not provide any details about the message types. One approach would be to limit the scope of the JBPM work to only dealing with its usage in a JBossESB context - and enhance the existing integration action handlers to include the additional required information.

Alternatively, maybe BPEL should be the next best target, as it does explicitly define this type of information.

Personally, I also like to use the BPEL as our next target, cause at the moment, we have already had some POC code in the pi4soa source tree. We can extend that effort. Secondly, I'd think the BPEL is the easiest mapping from the CDL flow definition.

What's the community voice here?

[marklittle]

Go with BPEL for now and target the same version and implementation we use for the ESB :-)

[jeffdelong]

I think going with the BPEL initially makes sense, although one concern here is that from a modeling perspective I don't know that the AE BPEL Designer is available on Eclipse 3.4 yet. and the latest JBoss and PI4SOA tooling is targeted at Eclipse 3.4.

As for jBPM, well the ESB Service Node does sort of support message types; that is there is an Input and Output variable mapping where the user can define the mapping of jBPM context variables to ESB Messages. This is more for mapping of Java objects, although it should support XML as well. However, once having mapping XML data into jBPM, jBPM is not able to work with XML data (can only store the string), and there is no equivalent of a BPEL "assign" to convert the XML into variables that could be used (say for conditional branching at a decision node).