Obtain Apex Triggers That Subscribe to a Platform Event

1. From Setup, enter Platform Events in the Quick Find box, then select Platform Events.
2. Click your event’s name.

On the event’s definition page, the Subscriptions related list shows all the active triggers that are subscribed to platform events. The list shows the replay ID of the event that the system last processed (Last Processed Id field) and the event last published (Last Published Id field). Knowing which replay ID was last processed is useful when there is a gap in the events published and processed. For example, if a trigger contains complex logic that causes a delay in processing large batches of incoming events.

Also, the Subscriptions list shows the state of each subscribed trigger. Trigger states can be one of the following.

• Running—The trigger is actively listening to events.
• Idle—The trigger hasn't received events for some time and is not actively listening to events. When new events are sent, the trigger receives the new events after a short delay and switches to the Running state.
• Error—The trigger has been disconnected and stopped receiving published events. A trigger reaches this state when it exceeds the number of maximum retries with the EventBus.RetryableException. Trigger assertion failures and unhandled exceptions don’t cause the Error state. To resume trigger execution, fix the trigger code and save it. For a managed package trigger, redeploy the package after fixing the trigger.
• Suspended—The trigger is disconnected and can’t receive events due to an internal error. To resume trigger execution, try saving the trigger again. For a managed package trigger, redeploy the package.

Alternatively, you can obtain the same subscriber information by querying the EventBusSubscriber object. See EventBusSubscriber.