Introduction to the IoT Edge SDK V1, part 5: Watchdog

Update: Recently, Microsoft introduced the new V2 version of their IoT Edge. This blog is referencing the former but still supported V1.

In the past weeks, I have shown how to work with the basics of the current Azure Edge SDK.

Today we will look at a more specific need, a watchdog.

Using this watchdog, we have more control over the quality of the service.

I created my watchdog when I discovered I was depending on the time-out of an HTTP request to find out the sensors were not working correctly. These timeouts can take a long time (there is an example of 100 seconds).

Because I expect a message every five seconds, I want to be warned if a message is not generated in nine seconds!

Azure Functions as watchdog for missing telemetry or devices

Once you are working with the Azure IoT platform, there comes a moment where you want to add notifications.

In a previous blog, we looked at how to send notifications when telemetry values did not match certain ranges. Although this is great, there are even more cases where we want notifications.

Here I am referring to watchdog functionality. When no telemetry is arriving anymore or devices are disconnected, the complete IoT platform is not working as designed. So we want to be informed when something fails.

In this blog, we will build a simple watchdog using Azure Functions.