Events are changes in the states or attributes of the objects that Orchestrator finds in the plugged-in technology. Orchestrator monitors events by implementing event handlers.

Orchestrator plug-ins allow you to monitor events in a plugged-in technology in different ways. The Orchestrator plug-in API allows you to create the following types of event handlers to monitor events in a plugged-in technology.

Listeners

Passively monitor objects in the plugged-in technology for changes in their state. The plugged-in technology or the plug-in implementation defines the events that listeners monitor. Listeners do not initiate events, but notify Orchestrator when the events occur. Listeners detect events either by polling the plugged-in technology or by receiving notifications from the plugged-in technology. When events occur, Orchestrator policies or workflows that are waiting for the event can react by starting operations in the Orchestrator server. Listener components are optional.

Policies

Monitor certain events in the plugged-in technology and start operations in the Orchestrator server if the events occur. Policies can monitor policy triggers and policy gauges. Policy triggers define an event in the plugged-in technology that, when it occurs, causes a running policy to start an operation in the Orchestrator server, for example running a workflow. Policy gauges define ranges of values for the attributes of an object in the plugged-in technology that, when exceeded, cause Orchestrator to start an operation. Policies are optional.

Workflow triggers

If a running workflow contains a Wait Event element, when it reaches that element it suspends its run and waits for an event to occur in a plugged-in technology. Workflow triggers define the events in the plugged-in technology that Waiting Event elements in workflows await. You register workflow triggers with watchers. Workflow triggers are optional.

Watchers

Watch workflow triggers for a certain event in the plugged-in technology, on behalf of a Waiting Event element in a workflow. When the event occurs, the watchers notify any worklows that are waiting for that event. Watchers are optional.