Transformation filter on query in panel with Mixed datasources and queries not working

What Grafana version and what operating system are you using?

Grafana v10.2.99-custom.company, from MacOS Sonoma 14.7.1, Google Chrome 131.0.6778.264 and also from Firefox

What are you trying to achieve?

I have two datasets:

  • Graphite metrics on some feature usage aggregated over the last year/6months
  • A MySQL RDS Grafana datasource SQL query which gets all the available feature names

What I wanna achieve is find the unused features in the last year/6 months, so find features for which there are no metrics/no data over 6M/1Y.

How are you trying to achieve it?

I have a Panel of vis type Table, Datasource type set to Mixed since I need data from Graphite and RDS. The goal is to create two tables, join them, and see for which feature the count is still 0.

I add 2 queries:

  • RDS SQL query which takes one column from a RDS table and adds a column with value 0 for every row (~150 rows)
  • Graphite query which returns a Frame/ Series (~120 series each with a couple of values)

Now I need to transform the Frame/Series into rows, so i can merge the 2 tables, but when I set the transformation to be filtered for the Graphite query it doesn’t work, the UI resets and the transformation is applied to both queries, ruining the RDS table.

The transformation is the Reduce, Mode Series to rows

What happened?

Transformation filter on a specific query doesn’t work. Filtering on the RDS query works, but filtering on the Graphite query isn’t working. I noticed that the filter doesn’t work for the Graphite query for other transformations as well, not just for Reduce, Mode Series to rows transformation.

Note that, as a test, having a panel with only the Graphite query and the transformation Reduce Series to rows works correctly, the issue comes when filtering the transformation in a panel with multiple queries and mixed data sources

What did you expect to happen?
Be able to filter the transformation on the Graphite query only

Can you copy/paste the configuration(s) that you are having problems with?
Graphite query is similar to

groupByNodes(summarize(aggregations.hourly.$server.features.by_group..by_feature..computetime.count, ‘6M’, ‘max’, false), ‘max’, 5, 7)

Did you receive any errors in the Grafana UI or in related logs? If so, please tell us exactly what they were.

No UI errors, the UI just resets to no filters after selecting the Graphite query. Note that in the filter dropdown the RDS query shows its name, while the Graphite query doesn’t display any name despite having one.

Did you follow any online instructions? If so, what is the URL?