mingwei-1231
Contributor
Contributor

You must have at least one list element (Query exception met when creating a dynamic variable)

Hi!

I am new to Wavefront so not sure if this is a stupid question..

Basically, I am trying to use a point tag dynamic variable in a dashboard. Let's say "source" for example.

When setting up the variable, it asks for a query.

This query, to my understanding, needs to return some metric that is shared by all the "source"s, and has "source" as one of its point tags?

But when I try to save the variable, it gives the following exception:

Query Exception

  • You must have at least one list element

I found a metric that gives me several lines if I do a simple ts() on it. I thought that's a list? But it's apparently not?

Then I want to ask, what is considered a list element? How should I see my metrics' data types (list or not)? What other types are there? I assume there is a documentation page I missed reading on this?

Or, if I am asking wrong questions, what does the error actually mean?

Thanks very much!

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Arritonsa
Contributor
Contributor

You can join the tables to find the relevant users, and use DISTINCT so each user is in the result set at most once even if they have multiple posts with rating. 


@mingwei-1231 wrote:

Hi!

I am new to Wavefront so not sure if this is a stupid question..

Basically, I am trying to use a point tag dynamic variable in a dashboard. Let's say "source" for example.

When setting up the variable, it asks for a query.

This query, to my understanding, needs to return some metric that is shared by all the "source"s, and has "source" as one of its point tags?

But when I try to save the variable, it gives the following exception:

Query Exception ________________________ Subway Live IQ App

  • You must have at least one list element

I found a metric that gives me several lines if I do a simple ts() on it. I thought that's a list? But it's apparently not?

Then I want to ask, what is considered a list element? How should I see my metrics' data types (list or not)? What other types are there? I assume there is a documentation page I missed reading on this?

Or, if I am asking wrong questions, what does the error actually mean?

Thanks very much!


 

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