Whenever a Business Process Server application receives a message, BP Server performs the following operations:
1. Find all process templates that have subscribed to this message in the start workstep and create instances for those process templates.
2. Search all process templates to find the list of all worksteps that are subscribed to the received message.
3. Find all existing process instances of such process templates. The process instances can be in a suspended or activated states.
4. Find all qualified subscriber workstep instances of these process instances found in step 3 by applying correlation condition, if any. BP Server ensures delivery of the message to these qualified workstep instances.
5. Save a reference of the message for each qualified workstep instance found in step 4.
BP Server ensures to deliver the message only to those Process Instances, which are in active or suspended state. It cannot deliver the message for process instances that are created in future.
In the aboveoperations, the first one requires BP Server to search all process templates of the system. This search can be narrowed down if the sender of the message specifies any of the following process data in the JMS header. These are called system properties that can be used by BP Server engine to narrow down the search for the qualified targets.
ReceiverInstanceId, and ReceiverTaskName
ReceiverAppName, and ReceiverTaskName
ReceiverAppName
In a publisher workstep, user can add these properties to the message header. For more information about this, see Messagepublisher workstep. When a message with the receiver information is received in a subscriber workstep, BP Server engine uses this data to narrow down the search to find out the qualified targets of this message.
ReceiverInstanceId, and ReceiverTaskName