CODEWITHSUNDEEP
grafanagrafana-templatinggrafana-variable
renzop
renzop

Reputation: 1316

How to plot horizontal line in Timeseries in Grafana

I use grafana to plot timeseries data. In a timeseries plot i want to add a constant line which comes from a monitoring level. The value of that level is dynamic (from a postgres database) the timeseries come from a ifluxdb Datasource.

The monitoring level have no timestamp. The result should look like this:

enter image description here

I have searched quite a while how to do this, but not found a good explanation.

Upvotes: 10

Views: 18634

Answers (4)

HTE
HTE

Reputation: 263

It is possible to add dynamic thresholds using the Config from query option.

  1. Add a new query below your standard metric query. This will likely be called B (tip: rename this to something more descriptive).

    Here you query the static reference value. Eg SELECT expected_number_of_widgets FROM baseline

  2. Open Transformation tab

  3. Find Configuration from Query results

  4. Choose Config query = B

  5. At the dropdown for expected_number_of_widgets, choose Use as: Threshold1.

  6. In the right panel, under Thresholds, make sure Show Tresholds is enabled and remove the default threshold of 80.

For more details, see https://grafana.com/docs/grafana/latest/panels-visualizations/query-transform-data/transform-data/#config-from-query-results

Upvotes: 8

Raph
Raph

Reputation: 554

You can now add thresholds (bottom of the edit screen).

Each threshold can be represented as a solid line and/or region with individual color

enter image description here

Upvotes: 8

mraczka
mraczka

Reputation: 21

Another way to do it in a dirty way is to create panel with a mixed data source. Create your variable in grafana - it can be a query, constant or custom. Just remember to keep it a single floating point. Add your original query and add the prometheus data source to query your variable.

${net_ordered_storage}

You will have to play a little bit with the number of data points displayed (query options>max data points) and minimum step of data point in prometheus query to make grafana connect dots.

Green horizontal line from variable

Upvotes: 2

renzop
renzop

Reputation: 1316

To draw a line like that you have to "fake" a timeseries. (thresholds don't work since they can not be dynamic as far as I know)

First thing to keep in mind is that grafana needs timestamp to plot it, for this reason the global variables ${__to} and ${__from} come in handy.

Then, to draw a line, grafana needs at least two points. ([t0, t1][y0, y1])

So this is the sql (postgre) query that lead to the desired result:

SELECT
  ${__from} AS time,
  level_1,
FROM my_table where display_name = '${my_grafana_var:raw}'
union all
SELECT
  ${__to} AS time,
  level_1,
FROM my_table where display_name = '${my_grafana_var:raw}';

Upvotes: 3

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