I have an IoTHub Trigger (Event Hub Trigger) function that appears to operate for a period of time, and will then stop executing. Restarting the Function App will show the buffered messages being processed as expected, but then the function will no longer trigger.
The Function App is running on a consumption plan and regularly receives telemtry messages from multiple devices (approximately 5 messages every 5 minutes).
I have searched our App Insights log and can find no warnings, or other messages that indicate a reason for the shutdown. I do see Information messages indicating "DrainMode mode enabled", followed by a number of Information messages indicating that Listeners for each of our functions are being stopped:
DrainMode mode enabled
Calling StopAsync on the registered listeners
Stopping task hub worker. IsGracefulStop: False. InstanceId: . Function: . HubName: . AppName: . SlotName: Production. ExtensionVersion: 2.1.1. SequenceNumber: 2.
Stopping the listener 'Microsoft.Azure.WebJobs.EventHubs.EventHubListener' for function ''
Task hub worker stopped.
`IsGracefulStop: False. Latency: 00:00:00.2389180. InstanceId: . Function: . HubName: <myhubname>. AppName: <myfunctionappname>. SlotName: Production. ExtensionVersion: 2.1.1. SequenceNumber: 3
Stopped the listener 'Microsoft.Azure.WebJobs.EventHubs.EventHubListener' for function 'myfunctionname'
Call to StopAsync complete, registered listeners are now stopped
Any ideas why the listeners are shutting down, and how I can prevent it from happening?
