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How Workflow Agent Ping/Acknowledge Works

Note: The item key for a process instance can only contain single-byte characters. It cannot contain a multibyte value.

When you launch the Master Ping process, the Workflow Engine identifies all the inbound agents that you have defined on the local system or on external systems and launches a Detail Ping process for each agent. The master process then waits for each detail process to complete.

The Detail Ping process begins by sending a Ping Agent event to the inbound agent identified by the master process. The detail process places a Ping Agent event message on a queue associated with an outbound agent on the local system. The event message is addressed to the inbound agent and contains a correlation ID that identifies the detail process to which it belongs. AQ propagation transmits the event message from the outbound queue to the queue associated with the specified inbound agent.

On the receiving system, the listener for the inbound agent dequeues the Ping Agent message the next time it runs. When the event message is dequeued, the Event Manager searches for and executes any active subscriptions to the Ping Agent event or the Any event on that system that have a source type of External.

When the predefined External subscription to the Ping Agent event is executed, its rule function places an Acknowledge Ping event message on a queue associated with an outbound agent on that system. The event message is addressed to an inbound agent on the originating system and includes the correlation ID from the Ping Agent event message. AQ propagation transmits the Acknowledge Ping event message from the outbound queue to the queue associated with the specified inbound agent.

On the originating system, the listener for the inbound agent dequeues the Acknowledge Ping message the next time it runs. When the event message is dequeued, the Event Manager searches for and executes any active subscriptions to the Acknowledge Ping event or the Any event on that system that have a source type of External.

When the predefined External subscription to the Acknowledge Ping event is executed, its rule function, which is the default rule function, sends the event message to the Detail Ping process. The Workflow Engine uses the correlation ID to match the message with the running detail process to which it belongs. After receiving the event message, the Detail Ping process completes.

Finally, after all the detail processes are complete, the master process also completes.

You can use the Workflow Monitor to check the progress of the Workflow Agent Ping/Acknowledge workflow. You can also use Oracle Workflow Manager to confirm the processing of the Ping Agent and Acknowledge Ping event messages. See: Workflow Monitor, Oracle Workflow Administrator's Guide and the Oracle Workflow Manager online help.

The amount of time needed to complete the Workflow Agent Ping/Acknowledge workflow depends on how often the listeners run to dequeue messages from the inbound agents. See: Scheduling Listeners for Local Inbound Agents, Oracle Workflow Administrator's Guide.

See Also

Summary of the Master Ping Process

Master Ping Process Activities

Summary of the Detail Ping Process

Detail Ping Process Activities

Ping Agent Events