Percentile Timer

The value is the number of seconds that have elapsed for an event, with percentile estimates.

This metric type will track the data distribution by maintaining a set of Counters. The distribution can then be used on the server side to estimate percentiles, while still allowing for arbitrary slicing and dicing based on dimensions.

In order to maintain the data distribution, they have a higher storage cost, with a worst-case of up to 300X that of a standard Timer. Be diligent about any additional dimensions added to Percentile Timers and ensure that they have a small bounded cardinality.

Call record() with a value:

import {Registry} from "nflx-spectator";

const registry = new Registry();
void registry.pct_timer("server.requestLatency").record(0.01);

const request_latency = registry.new_id("server.requestLatency");
void registry.pct_timer_with_id(request_latency).record(0.01);

const start = process.hrtime();
// do work
void registry.pct_timer("server.requestLatency").record(process.hrtime(start));

The record() method accepts number[] output from hrtime and converts it to seconds, as a convenience for recording latencies.