Dropdown menu in dashboards where data are coming from influxdb

[leonardoselex]

• What Grafana version and what operating system are you using?
  Grafana v9.5.0-cloud.5

• What are you trying to achieve?
  I have various dashboards for the data coming from influxdb. I want to create the dropdown menu for the different tags in my influxdata source, so that i can select one or two or all to view the data in different tags.

• How are you trying to achieve it?
  I am trying to achieve this using variables in dashboard settings. There are many options, among them i tried query options which didnot return my tags but returns values or nothing all the time. I am using flux query in every dashboards. So each dashboards has data for each tags in influx instead of that i want to select tag from dropwdown menu.
  I did create custom variable where i include my tags manually. now when i select the tag in the dropdown menu created using custom variable it didn’t work.

• What happened?

• What did you expect to happen?

If you notice the influxsb UI i am looking for similar dropdown menu where i can select different tags and visualize it in dashboads. Suppose right now in my dashboard i have data from all user with all tags, i want to select some user and some tags in that dashboard using dropdown menu. I

• Can you copy/paste the configuration(s) that you are having problems with?

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

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

[grant2]

Welcome @leonardoselex to the Grafana forum.

Here is how I use tag values in my dashboard using this:

[leonardoselex]

Thank you much for the reply. Yes for example i got the dropdown menu suposse of my tag “projectnumber”, but i select any one of them in the dropdown menu i still see the data from all the projectnumber in the dashboards. How do i solve this? thank you much again

[grant2]

Continuing with my previous example, the Flux query gets modified in Grafana using ${tag_name} like this:

from(bucket: "Mydata")
  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
  |> filter(fn: (r) => r["_field"] == "GeneratorTemperature")
  |> filter(fn: (r) => r["MyEquipNumber"] == "${GeneratorNumber}")
  |> filter(fn: (r) => more filters....
  |> aggregateWindow(every: v.windowPeriod, fn: last, createEmpty: false)
  |> yield(name: "last")

[leonardoselex]

thank you very very much. This works when i select item in a tag but the thing when i select select two poject number in a tag called projectnumber it says nodata.
How can we solve this?

Thank you much in advance

[grant2]

Continuing with my example, if we want to use two tag values (e.g. 301 and 303) in the same query, replace this line:

  |> filter(fn: (r) => r["MyEquipNumber"] == "${GeneratorNumber}")

with this:

  |> filter(fn: (r) => contains(value: r["MyEquipNumber"], set: ${GeneratorNumber:json}))

However, you may have issues with the legend and may need to create some overrides or transformations.

[leonardoselex]

thank you yes it works.

May be there was bit problem with loading the dashboard as soon as i configure the variables i made in the current dashboard.
Other dashboard without the use of the variable are loaded fine but with this its really slow.

Is there any effect of it ? any idea?

[grant2]

Apparently contains() can cause performance / speed issues. Maybe check this out and try it and report back here if you get it to work better.

[fercasjr]

contains() function is way to slow! If performance is an Issue, I recommend avoiding it at all costs.

what I do, is I build entirely the “filter” piece of the code, using another chained variable that makes another query using Variable1, then with reduce function and some trickery I reduce all my “selected values” to one single string.

then in my main query I use the “filter” like this:

|> filter(fn: (r) => ${Variable2})

Note, I cannot give a general piece of code because it is kind of specific to your data set, and you may need to add some “dummy” values in case the query returns a “null” string because.
|> filter(fn: (r) => ) will get you an error

[usman.ahmad]

Just curious as now this post seems more fitting for the InfluXDB category.

Please let me know if it OK to move it there…?

[grant2]

Yes, InfluxDB is the better category for this post.

I have adjusted: