TraceQL - How to get average duration of traces ?

[hugoallaine]

Probably a simple question, but I cannot find this information.
I read the doc and find some way to get traces by avg duration / trace duration but how can I get the avg trace duration from traces ?

In Tempo, I have some traces (2 for example here)

In Grafana, I can see the trace duration from Tempo

The goal is to get a the average trace duration (here (2.32+0.941)/2 = 1.6305)

In other words, I'd like to do something like this :
{ name="my_root_span_that_is_in_all_traces" } | avg(traceDuration)

I've probably missed this information, thanks in advance for your help

[joe-elliott]

avg_over_time was added recently and will be available in Tempo 2.7 in a few months.

The query would look something like:

{ trace:rootName="root span name" } | avg_over_time(trace:duration)

This should give you what you are looking for. In Tempo 2.6 the best way to get this information would be to use the metrics generators

[hugoallaine]

Thank you for your answer !
I tried metrics generators to do that by summing the average time of all root span (my traces don't have a root span that takes all the time of the trace) but it's not accurate in my setup because I have async mq (Pulsar) in the middle of the whole process and I cannot have the waiting time between two different "root" span with TraceQL. (or I missed another thing?)

I'll use your solution when Tempo 2.7 will be available.

[mdisibio]

It's a little different than average but you can get the p50 already with:

{ name="my_root_span_that_is_in_all_traces" } | quantile_over_time(duration, 0.5)

[joe-elliott]

good point! didn't think about that. definitely easier than setting up metrics generator

[hugoallaine]

It's a little different than average but you can get the p50 already with:

{ name="my_root_span_that_is_in_all_traces" } | quantile_over_time(duration, 0.5)

Thank you too for your answer !
This is a useful metric, I'll use it in my setup to complement the average.