grafana/docs/sources/datasources/prometheus.md
Ivana Huckova 7055c40cfc
Docs: Add info about Prometheus http method (#31651)
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* Update docs/sources/datasources/prometheus.md

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>
2021-03-05 11:30:26 +01:00

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title = "Prometheus"
description = "Guide for using Prometheus in Grafana"
keywords = ["grafana", "prometheus", "guide"]
aliases = ["/docs/grafana/latest/features/datasources/prometheus"]
weight = 1300
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# 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]({{< relref "add-a-data-source.md" >}}) 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.
| Name | Description |
| ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Name` | The data source name. This is how you refer to the data source in panels and queries. |
| `Default` | Default data source means that it will be pre-selected for new panels. |
| `Url` | The URL of your Prometheus server, e.g. `http://prometheus.example.org:9090`. |
| `Access` | Server (default) = URL needs to be accessible from the Grafana backend/server, Browser = URL needs to be accessible from the browser. |
| `Basic Auth` | Enable basic authentication to the Prometheus data source. |
| `User` | User name for basic authentication. |
| `Password` | Password for basic authentication. |
| `Scrape interval` | Set this to the typical scrape and evaluation interval configured in Prometheus. Defaults to 15s.
| `HTTP method` | Use either POST or GET HTTP method to query your data source. POST is the recommended and pre-selected method as it allows bigger queries. Change this to GET if you have a Prometheus version older than 2.1 or if POST requests are restricted in your network. |
| `Disable metrics lookup` | Checking this option will disable the metrics chooser and metric/label support in the query field's autocomplete. This helps if you have performance issues with bigger Prometheus instances. |
| `Custom Query Parameters` | Add custom parameters to the Prometheus query URL. For example `timeout`, `partial_response`, `dedup`, or `max_source_resolution`. Multiple parameters should be concatenated together with an '&amp;'. |
| `Label name` | Add the name of the field in the label object. |
| `URL` | If the link is external, then enter the full link URL. You can interpolate the value from the field with `${__value.raw }` macro. |
| `Internal link` | Select if the link is internal or external. In the case of an internal link, a data source selector allows you to select the target data source. Supports tracing data sources only. |
## Prometheus query editor
Below you can find information and options for Prometheus query editor in dashboard and in Explore.
### Query editor in dashboards
Open a graph in edit mode by clicking the title > Edit (or by pressing `e` key while hovering over panel).
{{< docs-imagebox img="/img/docs/v45/prometheus_query_editor_still.png"
animated-gif="/img/docs/v45/prometheus_query_editor.gif" >}}
| Name | Description |
| ------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Query expression` | Prometheus query expression, check out the [Prometheus documentation](http://prometheus.io/docs/querying/basics/). |
| `Legend format` | Controls the name of the time series, using name or pattern. For example `{{hostname}}` is replaced with the label value for the label `hostname`. |
| `Min step` | An additional lower limit for the [`step` parameter of Prometheus range queries](https://prometheus.io/docs/prometheus/latest/querying/api/#range-queries) and for the `$__interval` and `$__rate_interval` variables. The limit is absolute, it cannot modified by the _Resolution_ setting. |
| `Resolution` | `1/1` sets both the `$__interval` variable and the [`step` parameter of Prometheus range queries](https://prometheus.io/docs/prometheus/latest/querying/api/#range-queries) such that each pixel corresponds to one data point. For better performance, lower resolutions can be picked. `1/2` only retrieves a data point for every other pixel, and `1/10` retrieves one data point per 10 pixels. Note that both _Min time interval_ and _Min step_ limit the final value of `$__interval` and `step`. |
| `Metric lookup` | Search for metric names in this input field. |
| `Format as` | Switch between `Table`, `Time series`, or `Heatmap`. `Table` will only work in the Table panel. `Heatmap` is suitable for displaying metrics of the Histogram type on a Heatmap panel. Under the hood, it converts cumulative histograms to regular ones and sorts series by the bucket bound. |
| `Instant` | Perform an "instant" query, to return only the latest value that Prometheus has scraped for the requested time series. Instant queries return results much faster than normal range queries. Use them to look up label sets. |
| `Min time interval` | This value multiplied by the denominator from the _Resolution_ setting sets a lower limit to both the `$__interval` variable and the [`step` parameter of Prometheus range queries](https://prometheus.io/docs/prometheus/latest/querying/api/#range-queries). Defaults to _Scrape interval_ as set in the data source options. |
| `Exemplars` | Run and show exemplars in the graph. |
> **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]({{< relref "../panels/visualizations/graph-panel.md#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
| Name | Description |
| ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `Query expression` | Prometheus query expression, check out the [Prometheus documentation](http://prometheus.io/docs/querying/basics/). |
| `Step` | [`Step` parameter of Prometheus range queries](https://prometheus.io/docs/prometheus/latest/querying/api/#range-queries). Time units can be used here, for example: 5s, 1m, 3h, 1d, 1y. Default unit if no unit specified is `s` (seconds). |
| `Query type` | `Range`, `Instant`, or `Both`. When running **Range query**, the result of the query is displayed in graph and table. Instant query returns only the latest value that Prometheus has scraped for the requested time series and it is displayed in the table. When **Both** is selected, both instant query and range query is run. Result of range query is displayed in graph and the result of instant query is displayed in the table. |
| `Exemplars` | Run and show exemplars in the graph. |
## 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]({{< relref "../variables/_index.md" >}}) 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.
| Name | Description |
| ----------------------------- | ----------------------------------------------------------------------- |
| `label_names()` | Returns a list of label names. |
| `label_values(label)` | Returns a list of label values for the `label` in every metric. |
| `label_values(metric, label)` | Returns a list of label values for the `label` in the specified metric. |
| `metrics(metric)` | Returns a list of metrics matching the specified `metric` regex. |
| `query_result(query)` | Returns a list of Prometheus query result for the `query`. |
For details of what _metric names_, _label names_ and _label values_ are please refer to the [Prometheus documentation](http://prometheus.io/docs/concepts/data_model/#metric-names-and-labels).
#### 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]({{< relref "../variables/variable-types/global-variables.md" >}}) 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:
```
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`:
```
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 `=`.
### Ad hoc filters variable
Prometheus supports the special [ad hoc filters]({{< relref "../variables/variable-types/add-ad-hoc-filters.md" >}}) variable type. It allows you to specify any number of label/value filters on the fly. These filters are automatically
applied to all your Prometheus queries.
## Annotations
[Annotations]({{< relref "../dashboards/annotations.md" >}}) 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](https://prometheus.io/docs/prometheus/latest/configuration/alerting_rules/#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]({{< relref "../administration/view-server/internal-metrics.md">}}).
## Prometheus API
The Prometheus data source works with other projects that implement the [Prometheus query API](https://prometheus.io/docs/prometheus/latest/querying/api/) including:
- [Cortex](https://cortexmetrics.io/docs/)
- [Thanos](https://thanos.io/v0.17/components/query.md/)
For more information on how to query other Prometheus-compatible projects from Grafana, refer to the specific project documentation.
## 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]({{< relref "../administration/provisioning/#datasources" >}}).
Here are some provisioning examples for this data source:
```yaml
apiVersion: 1
datasources:
- name: Prometheus
type: prometheus
# Access mode - proxy (server in the UI) or direct (browser in the UI).
access: proxy
httpMethod: POST
url: http://localhost:9090
jsonData:
exemplarTraceIdDestinations:
# Field with internal link pointing to data source in Grafana.
# datasourceUid value can be anything, but it should be unique across all defined data source uids.
- datasourceUid: my_jaeger_uid
name: traceID
# Field with external link.
- name: traceID
url: 'http://localhost:3000/explore?orgId=1&left=%5B%22now-1h%22,%22now%22,%22Jaeger%22,%7B%22query%22:%22$${__value.raw}%22%7D%5D'
```
## Amazon Managed Service for Prometheus
The Prometheus data source works with Amazon Managed Service for Prometheus. If you are using an AWS Identity and Access Management (IAM) policy to control access to your Amazon Managed Service for Prometheus domain, then you must use AWS Signature Version 4 (AWS SigV4) to sign all requests to that domain. For more details on AWS SigV4, refer to the [AWS documentation](https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html).
> **Note:** Grafana version 7.3.5 or higher is required to use SigV4 authentication.
To connect the Prometheus data source to Amazon Managed Service for Prometheus using SigV4 authentication, refer to the AWS guide to [Set up Grafana open source or Grafana Enterprise for use with AMP](https://docs.aws.amazon.com/prometheus/latest/userguide/AMP-onboard-query-standalone-grafana.html).
If you are running Grafana in an Amazon EKS cluster, follow the AWS guide to [Query using Grafana running in an Amazon EKS cluster](https://docs.aws.amazon.com/prometheus/latest/userguide/AMP-onboard-query-grafana-7.3.html).
## Exemplars
> **Note:** This feature is available in Prometheus 2.26+ and Grafana 7.4+.
Grafana 7.4 and later versions have the capability to show exemplars data alongside a metric both in Explore and Dashboards.
Exemplars are a way to associate higher cardinality metadata from a specific event with traditional timeseries data.
{{< docs-imagebox img="/img/docs/v74/exemplars.png" class="docs-image--no-shadow" caption="Screenshot showing the detail window of an Exemplar" >}}
Configure Exemplars in the data source settings by adding external or internal links.
{{< docs-imagebox img="/img/docs/v74/exemplars-setting.png" class="docs-image--no-shadow" caption="Screenshot of the Exemplars configuration" >}}