How to use the selected period of time in a query?

Question

I'm using Grafana with Prometheus and I'd like to build a query that depends on the selected period of time selected in the upper right corner of the screen.

Is there any variable (or something like that) to use in the query field?

In other words, If I select 24hs I'd like to use that data in the query.

Answer 1

There are two ways that I know:

1. You can use the $__interval variable like this:

   increase(http_requests_total[$__interval])
   

There is a drawback that the $__interval variable's value is adjusted by resolution of the graph, but this may also be helpful in some situations.

2. This approach should fit your case better:

Go to Dashboard's Templating settings, create new variable with the type of Interval. Enable "Auto Option", adjust "Step count" to be equal 1. Then ensure that the "auto" is selected in corresponding drop-down list at the top of the dashboard.

Let's assume you name it timeRange, then the query will look like this:

increase(http_requests_total[$timeRange])

This variable will not be adjusted by graph resolution and if you select "Last 10 hours" its value will be 10h.