Posts tagged correlation
On the Oracle Technology Network, architecture section, my article titled “Fanning Out Events on the Oracle SOA Suite 11g Event Delivery Network” has just gone live:
This article describes:
how events can be used in Oracle SOA Suite 11g to have business processes impact each other in a meaningful way with maximum decoupling. Specifically, this article describes a solution for fanning out Event Delivery Network (EDN) events to a more fine-grained level. This allows a single event to influence multiple running instances of a Business Process Execution Language (BPEL) process. The article uses the following Oracle SOA Suite 11g components: BPEL , Mediator ,Event Delivery Network, Spring , Locator API , Composite Sensors
Not too long ago, one of my customers had the following requirement: a file with invoice-entries has to be processed each night; for all invoice entries for the same customer, we would like to start a single BPEL process instance that aggregates the entries and creates a single invoice. To process the entire file, one BPEL process instance needs to be created for every unique customer who has invoice entries in that file. Note however that the Inbound File Adapter knows nothing about the customers or about previously started process instances, it will simply invoke a BPEL process ‘service’ for each line it processes.
The figure illustrates the situation. Note however that the invoice entries need not be sorted, and could well look like this:
BPEL of course offers correlation – the mechanism that allows us to feed messages into already running BPEL process instances. However, before SOA Suite 11g PS5, an inbound operation in a BPEL process – Receive, OnMessage – either initiates an instance (and possibly a correlation set) or it can correlate the inbound message into a running instance. But it cannot do both. So for the customer requirement at hand, correlation as it was is not More >
This article describes an architectural pattern, implemented in the Oracle SOA Suite 11g, that is somewhat similar to the Oracle Database 11g Function Result Cache. It introduces a SOA Composite Application in the role of Result Cache. In its most simple form, the result cache is initialized – loaded with values -, used by other SOA applications that need the cached values, refreshed/reset when required and terminated. Through this ‘result cache’ – frequently used and not-so-frequently changed values that are published by (possibly remote, expensive or slow-reacting) web services or adapter services can be made available to local consumers in a simple, cheap and fast manner. We achieve this using the fast native SCA binding used for invoking in-container services exposed by fellow composite applications (that’s for speed) and the BPEL correlation mechanism (that’s for finding the result cache in the first place).
What the actual value of this pattern and implementation are is not yet entirely clear to me. Your feedback is appreciated. What I do know is that this article is also a good demonstration of using correlation and of applying some of the XML manipulation techniques More >