What am I missing?

Howdy !

I’m looking for advises regarding K6 results collection

Right now, I’m both exporting my scenario metrics to :

  • a JSON file
  • a Prometheus, with the native histograms option

My initial tests are nominal ones, with 1 call per seconds, during 30 seconds, which leads to 31 duration points collection

Whenever I visualize this nominal run results thru Grafana, thanks the related K6 Prometheus Native Histograms dashboard, I notice a discrepancy with the JSON file content :

The Grafana dashboard reports max & min requests durations in the Requests by URL table, but I can’t find those metrics back from the JSON file.

None of the http_req_duration Points found in this file report for the min and max figures from the Grafana table

Am I missing something here ?

Any advises regarding my metrics collection methodology would be appreciated

Hey @benoitlefevre,
welcome to the community forum :tada:

Prometheus remote write output works by aggregating the single points, this is the reason why it can provide statistics functions for it. Instead, the JSON output flushes the raw observations.

If you need the statistics using a JSON output then you have to post-process the JSON stream/file.

I hope it helps.