Azure function stops getting called from IoT Hub

Question

I have an IoTHub and a Function app containing a function (EventHubTrigger C#).

I can see that the IoTHub receives approx. 6 messages from my device per hour - and the function gets called and stores data in a database. The function calls execution time is between 15ms and 60ms. (Actually 15-60ms is during test, now that i look closer to the call log it tends more to be around 70-140ms)

My problem is that the function stops getting called after some time. This has happened a couple of times now. Today, it ran for approx. 10 hours and then the function does not get called anymore. Messages are still received in the IoThub.

I can invoke the function manually with test data, and that is handled correctly. But it is still not being called from the IoTHub.

The plan i am running is Pay As You Go - NorthEuropePlan (Consumption).

Any suggestions ?

Answer 1

10 hours and then the function does not get called anymore. Messages are still received in the IoThub.

Here is a similar issue, according to paulbatum’s reply, if the connection string contain EntityPath, which may cause the issue. Please check if your connection string contain EntityPath.

If possible, you could try to create a new Azure function with same code logic to check if same issue appear. And you could try to use App Service plan (and enable the Always On setting) to check if it will help resolve issue.