TSVB derivative not showing data when time < 4 hours

[bering (Kåre Bering)]

My use case is collecting wait stats from MS SQL server, these metrics records waits on different things, I collect these waits every 5 minutes.

These waits are just growing until the server restarts, so using TSVB with derivate works fine when keeping the time greater than the last 5 hours:

But when I change the time to the last 4 hours then the visualization goes blank:

Does anyone know why the TSVB goes blank?

Cheers

[flash1293 (Joe Reuter)]

On the x axis label you can see the date interval drops from 5minutes to 60 seconds. Derivative calculates the difference of the current bucket to the last one, so if your SQL server is only ingesting new documents every 2 minutes for example, there will be an empty bucket between all buckets containing data, so derivative will never be able to calculate a meaningful value which leads to all of the values being set to undefined.

You can "pin" the interval by switching to the "Panel options" tab and setting it to "5m".