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Documentation Grafana documentation Data sources Prometheus

Prometheus data source

Grafana includes built-in support for Prometheus. This topic explains options, variables, querying, and other options specific to the Prometheus data source. Refer to Add a data source for instructions on how to add a data source to Grafana. Only users with the organization admin role can add data sources.

Prometheus settings

To access Prometheus settings, hover your mouse over the Configuration (gear) icon, then click Data Sources, and then click the Prometheus data source.

Prometheus query editor

Below you can find information and options for Prometheus query editor in dashboard and in Explore.

Query editor in dashboards

Open a graph in edit mode by clicking the title > Edit (or by pressing e key while hovering over panel).

Note: Grafana modifies the request dates for queries to align them with the dynamically calculated step. This ensures consistent display of metrics data, but it can result in a small gap of data at the right edge of a graph.

Instant queries in dashboards

The Prometheus data source allows you to run “instant” queries, which query only the latest value. You can visualize the results in a table panel to see all available labels of a timeseries.

Instant query results are made up only of one data point per series but can be shown in the graph panel with the help of series overrides. To show them in the graph as a latest value point, add a series override and select Points > true. To show a horizontal line across the whole graph, add a series override and select Transform > constant.

Support for constant series overrides is available from Grafana v6.4

Query editor in Explore

Templating

Instead of hard-coding things like server, application and sensor name in your metric queries, you can use variables in their place. Variables are shown as dropdown select boxes at the top of the dashboard. These dropdowns make it easy to change the data being displayed in your dashboard.

Check out the Templating documentation for an introduction to the templating feature and the different types of template variables.

Query variable

Variable of the type Query allows you to query Prometheus for a list of metrics, labels or label values. The Prometheus data source plugin provides the following functions you can use in the Query input field.

For details of what metric names, label names and label values are please refer to the Prometheus documentation.

Using interval and range variables

Support for $__range, $__range_s and $__range_ms only available from Grafana v5.3

You can use some global built-in variables in query variables; $__interval, $__interval_ms, $__range, $__range_s and $__range_ms, see 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 busiest 5 request instances based on average QPS over the time range shown in the dashboard:

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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, using $__range_s:

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Query: query_result(max_over_time(<metric>[${__range_s}s]) != <state>)
Regex:

Using $__rate_interval variable

Note: Available in Grafana 7.2 and above

The $__rate_interval variable is meant to be used in the rate function. It is defined as max( $__interval + Scrape interval, 4 * Scrape interval), where Scrape interval is the Min step setting (AKA query_interval, a setting per PromQL query), if any is set, and otherwise the Scrape interval as set in the Prometheus data source (but ignoring any Min interval setting in the panel, because the latter is modified by the resolution setting).

Using variables in queries

There are two syntaxes:

• $<varname> Example: rate(http_requests_total{job=~"$job"}[5m])
• [[varname]] Example: rate(http_requests_total{job=~"[[job]]"}[5m])

Why two ways? The first syntax is easier to read and write but does not allow you to use a variable in the middle of a word. When the Multi-value or Include all value options are enabled, Grafana converts the labels from plain text to a regex compatible string. Which means you have to use =~ instead of =.

Annotations

Annotations allow you to overlay rich event information on top of graphs. You add annotation queries via the Dashboard menu / Annotations view.

Prometheus supports two ways to query annotations.

• A regular metric query
• A Prometheus query for pending and firing alerts (for details see Inspecting alerts during runtime)

The step option is useful to limit the number of events returned from your query.

Get Grafana metrics into Prometheus

Grafana exposes metrics for Prometheus on the /metrics endpoint. We also bundle a dashboard within Grafana so you can get started viewing your metrics faster. You can import the bundled dashboard by going to the data source edit page and click the dashboard tab. There you can find a dashboard for Grafana and one for Prometheus. Import and start viewing all the metrics!

For detailed instructions, refer to Internal Grafana metrics.

Provision the Prometheus data source

You can configure data sources using config files with Grafana’s provisioning system. Read more about how it works and all the settings you can set for data sources on the provisioning docs page

Here are some provisioning examples for this data source:

yaml Copy

apiVersion: 1

datasources:
  - name: Prometheus
    type: prometheus
    access: proxy
    url: http://localhost:9090