setting alert on custom metric in Application Insights

Question

I need to set an alert on custom metric in Application Insights. For testing, I sent custom metric from a console app and then in Azure portal, set the alert on that custom metric. but when we will move the app to production, how we can make it work. I assume , during installation, we will need to set the alerts but I will be sending the custom metric through my application, so how I will set alert on that metric in the beginning which does not exists yet.

Answer 1

There's a current limitation that you have to send a value for the metric at least once, to cause it to be a "known" / "valid" metric name to create an alert for.

Answer 2

John is correct. This is a desired behavior aimed at preventing customers from making an error when specifying the name of a metric and thus configuring and relying on an alert that will never fire.