Map all values from a query variables in a dashboard's panel

[imminent]

Hi,
I am using Grafana 9.2.0 and I have a use case whereby I have a query variable called host_name that maps an host id with a specific user friendly name. The variable is fine and all good. The variables works on dashboard load with the below options:

I have a specific panel with the following query:

round(sum by(service_name) (rate(my_metric{service_name="aService", host_id=~"$host_name"}[2m])),1)

In the panel’s definition, I have also set this override value:

This is fine if I select a specific (just one) host_name from the top menu, but if I select multiple values, it just creates a legend value in the panel of this kind:

host_name1 + host_name2 + hostname3 Total 2345

I would like to have each host_name and its value shown separately. How can this be done in a dynamic way?

Thank you

[yosiasz]

@imminent

would like to have each host_name and its value shown separately

What do you mean by this?

[imminent]

I mean that currently I can only show the following:

host_name1 + host_name2 + hostname3 Total 2345

with the calculation set to Total. It works fine when I have only one host_name, but I would like to have the total value for each of them, e.g.:

host_name1 Total 234, host_name2 Total 300 etc

Is this even something I can achieve?

[yosiasz]

Maybe look on the BInary Operation Transformation? Not sure what your data source is. would be better to do it on that side of things.

[imminent]

Sounds great, thanks. Never worked with it, but it looks like it should resolve my issue. Appreciated, thanks.

[imminent]

I should have mentioned that my data source is Prometheus. Does your suggestion apply to that as well? Thanks

[yosiasz]

One way to find out is to try and fiddle around with it

[imminent]

Thanks, I will have a better look. I can see that I can only apply Time and whatever is my service_name value to Binary Operations. It also looks like that allows more than I am looking for. I just need to treat individually each of the value from my var. I will see what I come up with.

[xiaonuno]

Hi, im not sure if you got your solution working but maybe i can help you or someone else in the future that stumble upon this.

When you select multiple values, Grafana will do a simple interpolation between the names (in this case, a “+”).

There is however a way to specify the format you want them to appear:

if you write

${variable_name:json}

It will convert the 2+ selections into a json-accepted format.

Grafana Template Variables Syntax