Crate metrics_observer_json

Observes metrics in JSON format.

Metric scopes are used to provide the hierarchy of metrics. As an example, for a snapshot with two metrics — server.msgs_received and server.msgs_sent — we would expect to see this output:

{"server":{"msgs_received":42,"msgs_sent":13}}

If we added another metric — configuration_reloads — we would expect to see:

{"configuration_reloads":2,"server":{"msgs_received":42,"msgs_sent":13}}

Metrics are sorted alphabetically.

Histograms

Histograms are rendered with a configurable set of quantiles that are provided when creating an instance of JsonBuilder. They are formatted using human-readable labels when displayed to the user. For example, 0.0 is rendered as "min", 1.0 as "max", and anything in between using the common "pXXX" format i.e. a quantile of 0.5 or percentile of 50 would be p50, a quantile of 0.999 or percentile of 99.9 would be p999, and so on.

All histograms have the sample count of the histogram provided in the output.

{"connect_time_count":15,"connect_time_min":1334,"connect_time_p50":1934,
"connect_time_p99":5330,"connect_time_max":139389}

Structs

JsonBuilder	Builder for JsonObserver.
JsonObserver	Observes metrics in JSON format.