top pipe not supported in pie chart

[tiny-pangolin]

Dashboard visualizations fail with a 422 error when using the top pipe to limit the amount of values even using a stats before the top pipe. Currently the workaround is to let Grafana limit the number of results shown to the user.

example of a query that returns an error:

 _time:1h AND tags.appname:traefik AND tags.host:$host | unpack_json | stats by(RequestPath) count()  | top 20

fixed query:

 _time:1h AND tags.appname:traefik AND tags.host:$host | unpack_json | stats by(RequestPath) count() 

[dmitryk-dk]

Hi @tiny-pangolin ! The pie charts, by default, use stats query type, and in this case, the query goes through stats API.
In the stats API, we can't use the top command.

{\"status\":\"error\",\"errorType\":\"422\",\"error\":\"the \\\"top 2\\\" pipe cannot be put after \\\"stats by (_time:20s) count(*) as \\\\\\\"count\\\\\\\"\\\" pipe in the query [* | stats by (_time:20s) count(*) as \\\"count\\\" | top 2]\"}"

I think this issue will be fixed when we implement the switch with different query types for different types of panels. Please check this issue.

[dmitryk-dk]

Hi @tiny-pangolin ! Could you try to build the pie chart with the new version of the plugin?

[tiny-pangolin]

I'm now able to use the top pipe in queries, and it behaves as it did before

[tenmozes]

i have a similar problem today, i guess the transform is the right option to do fix that

[tiny-pangolin]

The top pipe only works with the raw query type, but it doesn't work with the instant or range queries. When I run a range query or instant with the top pipe then I receive the following error.

error: the "top 20" pipe cannot be put after "stats by (RequestPath) count(*) as \"count(*)\"" pipe in the query [_time:[1733335485,1733339085] tags.appname:traefik tags.host:armin.local.shiftsystems.net | unpack_json | stats by (RequestPath) count(*) as "count(*)" | top 20]

@tenmozes the pie chart will work with the raw query and top pipe with transforms, or using an instant query with no transforms and no top pipe #61 has some examples for transforms

[dmitryk-dk]

At that moment, the only way to build a pie chart is to use transform functions and raw queries. Because the VLogs don't support the pipe when we are using stats queries. Maybe we need to update the logic on VL side.
Why should we use transform? - A pie chart needs numbers to render the pipe, but logs return something like
{"count": "123", "hits": "1"} etc.

[tiny-pangolin]

At that moment, the only way to build a pie chart is to use transform functions and raw queries.

As of 0.10.0 the plugin supports 3 types of query raw, range, and instant, and a pie chart can be made with 0 transforms using an instant query, but the top isn't supported as seen in my previous screenshot. If you need to use the top pipe in your query right now, it requires using a raw query plus transforms