opossum-prometheus

This library add Prometheus metrics to the opossum circuit breaker. It based on opossum-prometheus with some improvements:

• No direct dependencies, only peer dependencies on prom-client and opossum
• Written in typescript
• Custom labels
• Blacklist events if you don't need them
• Customization of metric names and default labels

ToC

• opossum-prometheus
  • ToC
  • Install
  • Usage
  • Docs
  • License

Install

With NPM:

1npm i -s @iamelevich/opossum-prometheus

With Yarn:

1yarn add @iamelevich/opossum-prometheus

With PNPM:

1pnpm add @iamelevich/opossum-prometheus

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Usage

1import CircuitBreaker from 'opossum';
2import promClient from 'prom-client';
3import { CircuitBreakerMetrics } from '@iamelevich/opossum-prometheus';
4
5const myCircuitBreaker = new CircuitBreaker(
6    async () => /* Do something */,
7    {
8        name: 'my-circuit-breaker',
9    }
10);
11
12const myCircuitBreakerMetrics = new CircuitBreakerMetrics({
13    enabled: true,
14    client: promClient,
15    registry: promClient.register,
16    circuitBreakers: [myCircuitBreaker],
17});
18
19await myCircuitBreaker.fire();
20
21console.log(await myCircuitBreakerMetrics.metrics);
22
23// # HELP circuit_breaker_counter Circuit breaker counter
24// # TYPE circuit_breaker_counter counter
25// circuit_breaker_counter{name="my-circuit-breaker",event="fire"} 1
26// circuit_breaker_counter{name="my-circuit-breaker",event="success"} 1
27
28// # HELP circuit_breaker_performance Circuit breaker performance summary
29// # TYPE circuit_breaker_performance summary
30// circuit_breaker_performance{quantile="0.01",name="my-circuit-breaker",event="success"} 0
31// circuit_breaker_performance{quantile="0.05",name="my-circuit-breaker",event="success"} 0
32// circuit_breaker_performance{quantile="0.5",name="my-circuit-breaker",event="success"} 0
33// circuit_breaker_performance{quantile="0.9",name="my-circuit-breaker",event="success"} 0
34// circuit_breaker_performance{quantile="0.95",name="my-circuit-breaker",event="success"} 0
35// circuit_breaker_performance{quantile="0.99",name="my-circuit-breaker",event="success"} 0
36// circuit_breaker_performance{quantile="0.999",name="my-circuit-breaker",event="success"} 0
37// circuit_breaker_performance_sum{name="my-circuit-breaker",event="success"} 0
38// circuit_breaker_performance_count{name="my-circuit-breaker",event="success"} 1
39

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Docs

Full documentation you can find in docs folder

Options:

Property	Type	Description
circuitBreakers?	CircuitBreaker[]	(Optional) List of circuit breakers to collect metrics for
client	typeof PromClient	Prometheus client
customLabels?	Record<string, string>	(Optional) Custom labels
enabled?	boolean	(Optional) If disabled - will not collect metrics
eventsBlacklist?	string[]	(Optional) List of opossum circuit breaker events to ignore
exposePerformanceMetrics?	boolean	(Optional) Expose performance metrics circuit*breaker_performance for events success and failure
overrides?	CircuitBreakerMetricsOptionsOverrides	*(Optional)_ Overrides for metrics. Let you change metric name and default labels
prefix?	string	(Optional) Prefix for metrics. Will be added to the beginning of metric name if no override provided
registry?	PromClient.Registry	_(Optional)_ Prometheus registry

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License

Licensed under MIT.

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