Life Cycle of a Production

When a production starts, the sequence of actions is as follows:

1. The production class is instantiated; its optional OnStart() method executes.

2. The production instantiates each business operation and executes its optional OnProductionStart() method.

3. The production instantiates each business process and executes its optional OnProductionStart() method.

4. The production clears the business metric cache of any metric values left over from a previous run.

5. The production instantiates each business service and executes its optional OnProductionStart() method.

6. The production processes any items already placed in queues. This includes asynchronous messages that were queued when the production stopped.

7. The production now accepts input from outside InterSystems IRIS® data platform.

When a production stops, the sequence of actions is as follows:

1. The production takes each business service offline and executes its optional OnProductionStop() method. This action stops all requests from outside InterSystems IRIS.

2. All business hosts receive a signal to become Quiescent.

3. All queues go into a Quiescent state. This means that from this point forward, business hosts can only process queued messages with High priority (synchronous messages). Asynchronous messages remain on their respective queues.

4. The production finishes processing all synchronous messages to the best of its ability.

5. The production takes each business process offline and executes its optional OnProductionStop() method.

6. The production takes each business operation offline and executes its optional OnProductionStop() method.

7. The production goes offline. InterSystems IRIS executes the optional OnStop() method in the production class.