Chapter 19 Working with Sybase Unwired Orchestrator
As in all executable business process modeling languages, Orchestrator business process instance identifiers are instantiated from attributes that exist within messages. As a result, the runtime engine requires a correlation mechanism for all messages to ensure that instances of various message types can be routed to the correct instance of the business process.
In Unwired Orchestrator, the correlation mechanism is known as a business process key and serves to bind all Notifications by enforcing the extraction of common elements from the message definitions.
Each Notification also requires a correlation identifier, which can be an attribute or collection of attributes, known as key component parts. The combination of component parts represents a unique identifier that can be used for message and business process instance management.
| Unwired Orchestrator concept | PowerDesigner concept |
|---|---|
| Key | Correlation key |
You associate a correlation key to a Notification service interaction using the InputCorrelation attribute of the process object. This attribute is available only for processes executing an operation and receiving a message.
The correlation key object is a collection of variable objects. Each variable owned by a correlation key does not represent a context variable but a property as in BPEL4WS. But this property exists within messages received by Notification activities.
So to extract this property from the message and to use it as key part you must use a data transformation object which must represent the expression that consist in extracting specific properties from a message received by the Notification service interaction.
| Unwired Orchestrator concept | PowerDesigner concept |
|---|---|
| Key part | Data transformation object with the following properties:
Stereotype = <<KeyPart>> Assigned Variable = Variable used within a correlation key Input Variable = Message format used in reception mapping of the Notification activity Expression = Xpath expression used as a KeyPart of the Key |
Orchestrator allows you to define a KeyPart as a Message Header prefixed value. Therefore the following extended attribute are available from the property sheet of the data transformation with a <<KeyPart>> stereotype:
| Extended attribute | Description |
|---|---|
| MessagePropertyPart | Message Property Part takes value from a list of predefined values. The following list represents transport based properties implemented by Open Transport that map the underlying physical property. All transport types share properties that are prefixed by "NNOT". Properties that are prefixed by "OPT" are Sybase legacy properties that may or may not be required: NNOT_MSG_ID, NNOT_MSG_EXPIRATION, NNOT_MSG_TYPE, NNOT_MSG_PERSISTENCE, NNOT_MSG_PRIORITY, NNOT_MSG_REPLY_ID, NNOT_MSG_REPORT, NNOT_MSG_LOCAL_TIME |
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