Issues with handling arrays containing NaN values in Grafana with "Extract Fields" transformation

Grafana Table Panel
1

During testing of our InfluxDB database, we encountered unexpected behavior from Grafana when handling arrays containing NaN values using the “Extract Fields” transformation. It appears that Grafana does not properly handle arrays when NaN values are present, leading to the removal of valid data.
Problem Details:

  • NaN Case: When an array contains NaN values, the entire array is discarded, resulting in a loss of valid data.
    immagine
    immagine1478×41 3.42 KB

    Impact: This issue leads to the removal of valid data present in arrays as soon as a NaN value is encountered, creating inconsistencies in displayed data and making accurate analysis difficult.
    Specific Requirement: Using the “Extract Fields” transformation, we need to split the values present in the array to place each value in a specific column. The goal is to obtain a table with the following columns:
    • Time
    • Value1 of the array
    • Value2 of the array
    • Value3 of the array
    Currently, when NaN values are present, we are unable to achieve this desired result.

Request: It would be helpful to have a more robust handling of arrays containing NaN values, possibly ignoring NaNs and preserving the valid data present in arrays. Any advice on how to work around this issue or any future updates to improve this functionality would be greatly appreciated.

Thank you for your support.

2

very nice and thorough but we dont have access to your influxdb so we cant see the structure or schema of your data. also we need some sample data

3

Here is an example of the data:

“Time”,“value”
2024-06-05 08:08:50,“[0.2445265, nan, nan]”
2024-06-05 08:09:10,“[0.262936126, 0.8086975, 0.83012696388]”
2024-06-05 08:09:31,“[0.270746778544, 0.55487438, 0.4925401356]”
2024-06-05 08:09:51,“[0.42829332999, 0.34468964789, nan]”
2024-06-05 08:10:10,“[0.21768822589, 0.54960203942, 0.527942999785]”

1 Like
4

are you using flux query or influxql query?

5

influxql query

6

so extract is not going to work. what visualization do you want for this? might need to do some post processing in something else

7

The goal is to obtain a table with the following columns:
• Time
• Value1 of the array
• Value2 of the array
• Value3 of the array