Shared execution context support in SOA Suite Products

Question

Context:
An enterprise application is likely to be made up of components that span across the BPEL, JEE (servlets and EJBs) and ESB containers with heterogeneous mix of technologies/computing languages (especially if part of that application is a legacy application), communication protocols, transport, QoS capabilities etc. The latter opens up a complex set of related issues such as assertion, ownership and enforcement of policies and contracts (both infrastructure-oriented such as security, privacy, manageability and business-oriented such as hours of business, goods return policies) that must be managed in order for the application to behave consistently end to end. In a way, this concept is similar to one of header vs payload distinction.
Goal:
Yet those heterogeneous resources and technologies mentioned above should be abstracted (or externalized) from the business intent, ie the actual data and associated functional processing that deliver real benefits to business, as contextual information that may be both out-of-band and in-band (ie something that is created during the course of an interaction). In this way, the business components (BPEL scripts, presentation tier actions [as opposed to controllers], POJOs, or ESB mediation services implemented using XSLT scripts etc) can be reused in completely new unplanned scenarios with newer execution platforms/infrastructure since the latter can be made virtualized from the point of view of the business components.
To achieve the above, one of the key enabling factors is a shared execution context to capture such dynamic relationships between the application modules or components or services that is technology neutral but can be passed from one containers to the other seamlessly.
Problem:
Having understood the context and goals, the big question is what is the level of support for a shared context implementation found in Oracle BPEL, JEE and ESB containers? Especially in the ESB container since it is the execution environment of all services.
This overarching problem may be decomposed to the following:
* How far is loose coupling of services implemented? Strictly pure XML over HTTP or web services between tiers/containers?
* If it is pure web services everywhere, what about the impedance mismatch problem between POJOs and XML?
* If so, what is the form of a message dispatch/invocation framework to be put in place between tiers/containers? WSIF/AXIS? The choice will obviously be influenced by NFRs and to some extent the ease of integration of such frameworks with Oracle products runtime libraries.
* How does a service lookup another, at design-time or run-time?
* What mechanisms are there in each of the 3 containers above to allow for dynamic service assembly and dependencies injections?
* How should a message be structured (header vs payload)?
* How easy is the header or context that is most likely to be expressed in XML format be mapped to a run-time artifact in each of the containers? Is this mapping process lossless? This header is more than likely to carry a diverse range of information such as session and authentication tokens, management data, logs, audit trails, errors/exceptions and other QoS data.
In attempting to design and implement the above architectural requirements on Oracle SOA suite, I am unable to find any semblance of a design or runtime construct or artifact that is remotely close to what I would call a shared context. Should I conclude therefore that I would have to build the above facilities from ground up, instead of being able to customize a shared context construct or feature in Oracle SOA suite (the ESB container in particular)? I would have thought this is a fundamental capability of an integration platform such as Oracle SOA suite, am I right?

Answer 1

I supposed to make my previous question more concrete, the first answer I need before moving on to the rest of the bigger questions is this ...
What is Oracle’s recommendation for a services invocation framework between BPEL, JEE and ESB containers? From a quick read of Oracle Technet website, WSIF seem to be the preferred framework for this purpose. However, from an equally quick survey of such frameworks in use today outside of Oracle, WSIF does not seem to enjoy any widespread developer community support anymore and all talk in public forum seem to point to newer Apache Frameworks such as CXF which support emerging standards such as JAX-WS 2.0 What is the current stand of Oracle with respect to this matter?