kamon with statsd backend: histogram median aggregation is wrong

Question

I use kamon for a scala project and collect some metrics with Kamon.histogram. I use stastd + graphite + grafana as the backend. I record about 200 events per second. The statsd has the flushInterval of flushInterval: 10000, (10 seconds), and kamon has tick-interval = 10 seconds.

I noticed that the median (and all the other percentiles) are computed wrong. Furthermore, when I change the tick-interval of kamon to 1second, the median value changes, becoming closer to the correct one (but still not quite).

Answer 1

This turned out to be a bug in kamon-statsd: https://github.com/kamon-io/kamon-statsd/issues/6