When a model receives an event, it may be dropped if the correlator delivers or processes it too late. See Input blocks and event timing.

The total number of dropped events across all models is periodically published as part of the status operation. The count of the number of dropped events is available as a user-defined status value with the name user-analytics-oldEventsDropped in the apama_status parameter of the status operation. See also Monitoring periodic status for details about the operation.

All dropped input events are also sent to channel AnalyticsDroppedEvents, allowing you to implement your own monitoring of the dropped events. A dropped input event sent to the channel AnalyticsDroppedEvents is packaged inside an event of type apama.analyticsbuilder.DroppedEvent. This allows you to extract the original dropped event and perform any analysis on it, for example, categorizing the number of dropped events per device. This can be achieved by writing EPL that listens for the DroppedEvent events, aggregates by device identifier and/or time, and sends measurements to Cumulocity IoT that can be monitored. See the Streaming Analytics guide at http://cumulocity.com/guides/ for information on how to deploy EPL applications.