The Engine Status view displays the information about the correlator status. The information is the same as the output of Apama command line tool engine_watch.

Uptime(ms) — The time in milliseconds since this correlator was started. This figure is unaffected if the state of the correlator is restored from a checkpoint file.

Number of contexts — The number of contexts in the correlator. This includes the main context plus any created contexts.

Number of monitors — The number of monitor definitions injected into the correlator. This figure changes upwards and downwards as monitors are injected, deleted or just expire. A monitor expires when each of its instances dies, has no listeners left, or causes a runtime error.

Number of sub-monitors — The number of monitor instances across all contexts in the correlator. In monitors, spawn actions create monitor instances. This figure changes upwards and downwards as monitor instances are spawned, killed or just expire.

Number of java applications — The number of Java applications loaded in the correlator. Java applications do not expire, so this value only decreases when you explicitly unload a Java application.

Number of listeners — The number of event listeners created by monitor instances across all contexts, plus the number of Java applications.

Number of sub-listeners — The number of sub-listeners that have been created by listeners across all contexts.

Number of event types — The total number of event types defined within the correlator. This figure decreases when you delete event types from the correlator.

Events on input queue — The sum of the number of events on the input queue of each context. The main context has its own input queue and any user-defined contexts each have an input queue.

Events received — The total number of events ever received by the correlator. A checkpoint preserves this value. If you restore the state of the correlator from a checkpoint file, this number reflects the total number of the events seen by the correlator from which the checkpoint was originally made. Note that if an event is on an input queue, it has been received but not processed.

Events processed — The total number of events processed by the correlator in all contexts. This includes external events and events routed to contexts by monitors. An event is considered to have been processed when all listeners that were waiting for it have been triggered, or when it has been determined that there are no listeners for the event.

Events on internal queue — The sum of the number of routed events on the input queue of each context. The internal routing queue in each context is a high priority queue for events that you internally routed with the route instruction in your EPL files. The correlator always processes routed events before processing events on the input queue.

Events routed internally — The sum of the number of events routed in each context since the correlator started. A checkpoint preserves this value. If you restore the state of a correlator from a checkpoint file, this number reflects the total number of the events routed to the internal queues for the correlator from which the checkpoint was originally made.

Number of consumers — The number of event consumers registered with the correlator. Event consumers receive events emitted by the correlator.

Events on output queue — The number of events waiting on the correlator’s output queue to be dispatched to any registered event consumers.

Output events created — The total number of output events created by the correlator. A checkpoint preserves this value. If you restore the state of a correlator from a checkpoint file, this number reflects the total number of output events created by the correlator from which the checkpoint was originally made.

Output events sent — The total number of output events that the correlator has sent to event consumers. For example, suppose the correlator created 10 output events and sent each event to two consumers. The number of output events sent is 20. A checkpoint preserves this value. If you restore the state of a correlator from a checkpoint file, this number reflects the total number of output events sent by the correlator from which the checkpoint was originally made.