Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions (Addison-Wesley Signature Series (Fowler))

by Hohpe Gregor

Because the process execution can span many steps and can therefore take a long time, the Process Manager needs to be prepared to receive new trigger messages while another process is still executing. In order to manage multiple parallel executions, the Process Manager creates a new process instance for each incoming trigger message. The process instance stores the state associated with the execution of the process initiated by the trigger message. The state includes the current execution step of the process and any associated data. Each process instance is identified by a unique process identifier.