From 0f99e624b680b60e00ca05f408c5b85464d7cf81 Mon Sep 17 00:00:00 2001 From: Marcus Efraimsson Date: Wed, 25 Jul 2018 16:20:00 +0200 Subject: [PATCH] docs: using interval and range variables in prometheus Included example usages --- .../features/datasources/prometheus.md | 21 ++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/docs/sources/features/datasources/prometheus.md b/docs/sources/features/datasources/prometheus.md index 0ed9e108df6..3a04ef92e31 100644 --- a/docs/sources/features/datasources/prometheus.md +++ b/docs/sources/features/datasources/prometheus.md @@ -80,7 +80,26 @@ For details of *metric names*, *label names* and *label values* are please refer > Support for `$__range` and `$__range_ms` only available from Grafana v5.3 -It's possible to use some global template variables in Prometheus query template variables; `$__interval`, `$__interval_ms`, `$__range` and `$__range_ms`, where `$__range` is the dashboard's current time range and `$__range_ms` is the current range in milliseconds. +It's possible to use some global built-in variables in query variables; `$__interval`, `$__interval_ms`, `$__range` and `$__range_ms`, see [Global built-in variables](/reference/templating/#global-built-in-variables) for more information. These can be convenient to use in conjunction with the `query_result` function when you need to filter variable queries since +`label_values` function doesn't support queries. + +Make sure to set the variable's `refresh` trigger to be `On Time Range Change` to get the correct instances when changing the time range on the dashboard. + +**Example usage:** + +Populate a variable with the the busiest 5 request instances based on average QPS over the time range shown in the dashboard: + +``` +Query: query_result(topk(5, sum(rate(http_requests_total[$__range])) by (instance))) +Regex: /"([^"]+)"/ +``` + +Populate a variable with the instances having a certain state over the time range shown in the dashboard: + +``` +Query: query_result(max_over_time([$__range]) != ) +Regex: +``` ### Using variables in queries