Azure App Insights how can sum of a metric go downwards when the values are always that are logged are always positive?

Question

I have a metric that I'm tracking using TelemetryClient.TrackMetric and the values I'm reporting are always positive (time duration in seconds), yet the chart of my custom metric with "Summation" selected goes down hill. How is this possible?

Answer 1

The metrics in the Azure Portal are always displayed depending on a certain time granularity. So, for example, if you select the time range "last hour" and time granularity "5 minutes" you will get 12 data points displaying the sum (or any other selected aggreagtion) of whatever metric you have selected. It does not aggregate the metrics for the complete time range, only per selected granularity.

The dotted line means that no data has arrived for these timestamps yet.