brakes-prometheus

Expose Brakes metrics as Prometheus data

Usage

Add event listeners to a brakes instance, using prom-client. This module has a peer dependency on prom-client. Currently, version 10 is supported.

import Brake from 'brakes';
import addEventListeners from 'brakes-prometheus';
import { register as prometheusRegister } from 'prom-client';
 
const myBrake = new Brake(() => Promise.resolve(), { name: 'some name' });
 
addEventListeners(myBrake);
 
setInterval(() => {
    console.log(prometheusRegister.metrics());
}, 500);

Naming metrics

You can supply an additional options object to set a prefix for the metric names.

addEventListeners(myBrake, { prefix: 'my_application_prefix_' });
 
// provides "my_application_prefix_breaker_execute_total" and so on

Metrics exposed

This module exposes 9 metrics, all using the name of the Brake as the label:

1. breaker_execute_total, 'Resolver circuit breaker execute count' (Counter)
2. breaker_success_total, 'Resolver circuit breaker success count' (Counter)
3. breaker_failure_total, 'Resolver circuit breaker failure count' (Counter)
4. breaker_timeout_total, 'Resolver circuit breaker timeout count' (Counter)
5. breaker_reject_total, 'Resolver circuit breaker reject count' (Counter)
6. breaker_circuit_closed_total, 'Resolver circuit breaker circuit closed count' (Counter)
7. breaker_circuit_opened_total, 'Resolver circuit breaker circuit opened count' (Counter)
8. breaker_duration_seconds: 'Resolver circuit breaker duration summary' (Summary)
9. breaker_duration_buckets_seconds: 'Resolver circuit breaker duration buckets' (Histogram)