Databases Reference
In-Depth Information
Message Interaction Patterns
In every composite, messages are exchanged between participants. So far, we have
only looked at simple interactions, that is, a single request followed by a reply,
whether synchronous or asynchronous.
Asynchronous messaging adds additional complexities around the routing and
correlation of replies. In this chapter, we look at how the SOA Service Infrastructure
uses WS-Addressing to manage this, and in situations where this can't be used,
examine how we can use correlation sets in BPEL to achieve the same result.
As a part of this, we look at some common, but more complex, messaging patterns
and requirements such as:
•
How we can handle multiple exchanges of messages, either synchronous or
asynchronous between two participants
How BPEL can be used to aggregate messages from multiple sources
Although it is not strictly a message interaction pattern, examine one
technique for process scheduling
•
•
Finally, as we explore these patterns, we take the opportunity to cover some
of BPEL's more advanced features, including
FlowN
,
Pick
, and
Dynamic
Partner Links
.
Messaging within a composite
Before looking at messaging patterns in detail, it's worth taking a moment to provide
a high-level overview of how messaging is handled within a composite.
