Best Practices: SOA Application Design Analysis

Messages and Correlation Sets

If asynchronous communication is required between a process and its partners, there may be a need to identify correlation data that can be used by the ActiveVOS BPEL orchestration engine to route callback messages to their intended recipients.

Message correlationdata needs to be defined for each callback. Sometimes this may be a simple identifier that can be extracted from an inbound messages and sometimes this may be a combination of several pieces of data (for example, a process id and a sequence number). The BPEL term for such data fragments is called a property. The BPEL term for the rules that specify how values are extracted from a particular message is called property alias.

The term used for the complete set of correlation data that can be used for correlating a single callback is called correlation set. Multiple correlation sets may be used in one process to handle callbacks from multiple partners.

ActiveVOS engine-managed correlation(video link - registration required) should be considered as a means of simplifying asynchronous message exchanges with partners, particularly when WS-Addressing is supported by the partner's service.

The handling of callbacks resulting from asynchronous communication is important and to be clearly understood early in the project.