How to add units to a timeseries panel with dynamic metrics sourced from DynamoDB

Grafana Dashboards
1

Hi all,

I am using Cloud Hosted Grafana (v13.0) and my data source is DynamoDB.

I have a simple dashboard with a multi-value variable (30 options) where the user can select some metrics to plot on a timeseries chart. This works fine.

I have a separate DynamoDB table which contains a list of all the available metrics and their corresponding units, for example Room_Temperature : degC, Rain_Guage : mm, Wind_Speed : km/h and so on. It’s a ‘lookup table’.

At the moment, when I select some metrics from the drop-down variable I can see all the series on the panel but they are all plotted on the same Y-axis and I don’t have any units displayed. I would like to display the units on the Y-axis, and ideally have a new Y-axis for each unit type.

It sounds so simple but I have had no success. I realise I could add 30 static overrides but this doesn’t seem like a good strategy. I would like to use a transformation (or similar) like the “Config from query results” which I believe can do this but I can’t get it to work. When I add that transformation I have only “A” as my Config Query Option. If I create a 2nd query (B) to fetch the units from DyanmoDB, I can’t see this query in the transformation option.

If anyone has achieved this before I would much appreciate any advice.

Thanks

Mike

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Unit show in tooltip when you hover on this (Use add field override property)
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3

Thanks for the reply but this solurtion is not really practical in my situation as described in my post.

4

Please provide sample data as csv inline here in the forum

metric,value,unit,datetime

or provide schema definitions DDL

Create table unit_types(Id,unitname)

Create table metrics(id,metric,value,unittypeid,datetime)
5

Grafana can’t automatically create a separate Y-axis for each metric, but you can handle it efficiently by combining your metrics with the unit lookup table. This way, each series knows its unit, and you only need a few overrides, one per unit type instead of one per metric.

  • Keep your main metrics query (Query A)
  • Add a second query for the lookup table (Query B) with metric - unit
  • Use the “Outer join” transformation to merge them on the metric name
  • Create one Y-axis override per unique unit type (°C, mm, km/h, etc.)
  • All metrics sharing the same unit will use the same Y-axis