Monday, 23 June 2008

Response to Luis's comments in my last blog entry

Firstly thank you for the comment Luis.

It has been a little while since I last blogged. In that time the latest Pi4SOA release came out. Some of it's capabilities are listed below in the narrative.

To get the latest release follow the instructions at the end.

On to my response to Luis's comments.

Luis wrote:

Very good article indeed. It clearly describes the main doubts most people have regarding the real added value of CDL and how to addressed it. It is clear vendors are more worried about short term ROI other than best practices and real heterogeneous enterprise architecture; evidence of this is how vendors sell “SOA Suites” as a product / package and not as an architecture approach or practice as it should be (this is probably one of the reasons why many SOA projects end up in DOA –dead on arrival– instead of addressing the real business needs and technological value)

One suggestion; it would be nice to mention how and when CDL can be plug together with other technologies such as BPMN, SCA and BPEL on the different stages of a SOA project and the roll it has one the solution is in place (e.g. in the governance).


Here is my response:

The Pi4SOA tools suite currently supports BPMN. It is simply and export format in which CDL is exported to BPMN. However CDL is richer that BPMN so it is not free from loss of the expressions in CDL. However it may serve the role of review collateral.

BPEL is also supported. You can generate BPEL just as you can generate Java. The downside is that BPEL is more restrictive than CDL because CDL is wider than classic web services and provides message exchange patterns that BPEL cannot handle but which are applicable to SOA (i.e. first class notifications). The BPEL generation is still prototypical as it does not garner much demand. However I think that Overlord will change that.

As to SCA, no current bindings exist to SCA but I do not think that SCA in and of itself is really a target for CDL as it fits two level below rather than one level below. One might of course make the association of SCA to ESB in which case the latest release supports JBossESB out of the box. The problem with ESB's is that there is not real standard. Rather an ESB is a collection of integrated components (Message Bus, Orchestration, Registry, Business Rules and adapters).

Governance is all about control and traceability. This is exactly what CDL provides as an SOA blueprint for a dynamic model. It is the language of architecture in which Java, C# and BPEL provide business logic inside services and in which CDL describes the collaborative behavior of the services as peers. It provides traceability back to requirements (example messages and sequence diagrams) today and in the future will also deal with the non-functionals (SLA's WS-Policy statements and so on) and it provides total coherence to implementation through Java generation, UML (XMI model) generation, and BPEL generation as well as providing runtime checking of behavior against the description. So it provides top to bottom alignment from requirements to implementation. In this way it provides a governance platform that can help to manage the complexity of change over a large real-estate of services. Which is why Cognizant and Redhat are interested in CDL.

Downstream we might try to join it up with ArchiMate, which will provide the route to requirements from the business. But that is some time away and work has yet to start. If anyone is interested then contact me at at the Foundation (see below).

To use the latest release follow the steps below:

1. Go to www.pi4soa.org
2. Select "Download->Browse All Files
3. Press the green "Download" button
4. Select the appropriate platform and download (See below)

pi4soa2.0.0.CR1-eclipse3.3.2-linux.tar.gz
pi4soa2.0.0.CR1-eclipse3.3.2-macosx.zip
pi4soa2.0.0.CR1-eclipse3.3.2-win32.zip
pi4soa2.0.0.CR1-Release-Note.pdf
pi4soa2.0.0.CR1-withsrc.zip
pi4soa2.0.0.CR1.zip
pi4soa.sar

I also have lots of example which I am happy to share. To get them you will need to email me at pi4tech (steve@pi4tech.com)

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