Azure Monitor Managed Service for Prometheus template variables
Template variables let you create dynamic, reusable dashboards by replacing hard-coded values, such as instance names, namespaces, or job labels, with selectable variables. Grafana displays these variables as drop-down menus at the top of the dashboard, so viewers can change the displayed data without editing queries. The Azure Monitor Managed Service for Prometheus data source supports the same template variable features as the core Grafana Prometheus data source.
Before you begin
Before you create template variables, ensure you have:
- Configured the Azure Monitor Managed Service for Prometheus data source.
- A basic understanding of Grafana template variables.
Supported variable types
The data source supports the following template variable types.
Create a query variable
Query variables get their values from your workspace. To create a query variable:
- Navigate to Dashboard settings > Variables.
- Click Add variable.
- Select Query as the variable type.
- Select the Azure Monitor Managed Service for Prometheus data source.
- Select a query type and enter the query details.
- Click Apply to save the variable.
Query variable types
When you select Query as the variable type, choose a query type that determines how Grafana populates the drop-down values.
Note
The Classic query type supports functions such as
label_names(),label_values(label),label_values(metric, label), andmetrics(regex). For new variables, use the dedicated query types instead, because the classic syntax is deprecated.
Query type examples
Populate a drop-down with all job label values. Set Query type to Label values, set Label to job, and leave Metric empty:
- Query type: Label values
- Label:
job
Show only the instances that report CPU metrics. Set Query type to Label values, Label to instance, and Metric to node_cpu_seconds_total:
- Query type: Label values
- Label:
instance - Metric:
node_cpu_seconds_total
Populate a drop-down with all metrics whose names contain node. Set Query type to Metrics and enter a regular expression in the Metric field:
- Query type: Metrics
- Metric:
node_.*
List the top five instances by request rate. Set Query type to Query result and enter a PromQL query:
query_result(topk(5, sum by (instance) (rate(http_requests_total[$__range]))))Because Query result returns full series strings, set Regex to /instance="([^"]+)"/ to extract the instance values, and set Refresh to On time range change so the results update with the dashboard time range.
Query options
The query variable editor provides the following options.
Selection options
- Multi-value: Lets viewers select multiple values at once. Grafana joins the selected values with a pipe (
|) for regular expression matching. - Include All option: Adds an All option that selects every value. Combined with multi-value, this produces a regular expression such as
value1|value2|value3.
Note
When Multi-value or Include All option is enabled, use the
=~regular expression match operator instead of=in your label matchers, because the variable value becomes a regular expression pattern.
Chain variables
You can reference one variable in another variable’s query to create dependent, or cascading, variables. For example, if you have a job variable, create an instance variable whose values depend on the selected job:
label_values(up{job="$job"}, instance)When you change the job variable, Grafana refreshes the instance variable to show only the instances for that job.
Use variables in queries
Reference a variable in a query with one of the following syntaxes.
When a variable allows multiple values, use the =~ regular expression match operator so the query matches any selected value:
rate(node_cpu_seconds_total{instance=~"$instance"}[$__rate_interval])Use the rate interval variable
$__rate_interval is a Grafana-specific variable designed for use with rate() and increase(). It guarantees a range window large enough to capture at least four scrape samples, which prevents gaps or inaccuracies. Always use $__rate_interval instead of a fixed interval or $__interval:
rate(http_requests_total[$__rate_interval])Grafana calculates $__rate_interval as max($__interval + scrape_interval, 4 * scrape_interval), where scrape_interval is:
- The per-query Min step setting, if set.
- Otherwise, the data source Scrape interval setting under Interval behavior on the configuration page.
To get reliable results, set the data source Scrape interval to match the scrape interval of the workspace. If your data uses a longer interval than the default and you leave the setting too low, $__rate_interval calculates too small a window and rate() can return no data.
Note
Don’t use
$__rate_intervalin workspace recording rules. The interval depends on the evaluation context, so use a fixed interval such as[5m]in recording rules instead.
Filters variable
The Filters variable, formerly called ad hoc filters, lets dashboard viewers add label filters without editing queries.
Grafana applies the filters to every Azure Monitor Managed Service for Prometheus query on the dashboard.
To set up a Filters variable:
- Create a new variable with Type: Filters.
- Select the Azure Monitor Managed Service for Prometheus data source.
- Save the dashboard.
A filter bar appears at the top of the dashboard. Viewers add filters by selecting a label, an operator (=, !=, =~, or !~), and a value. For example, when a viewer adds the filter namespace = production, all queries on the dashboard include {namespace="production"} without any query changes.
Note
Grafana applies Filters to all queries that use the selected data source. You can’t apply them to specific panels only.
