adonis5-prometheus

Adonis5-Prometheus

Simple Prometheus Wrapper for Adonis

Installation

npm i adonis5-prometheus
node ace configure adonis5-prometheus

Usage

A configuration file has been added in config/prometheus.ts.

By default the system metrics are collected ( systemMetrics.enabled: true ), so now you can call the endpoint {{host}}/metrics to get the measured metrics.

Here is an example scrape_config to add to prometheus.yml:

scrape_configs:
  - job_name: my-adonis-app
    static_configs:
      - targets: [my-adonis-app.com]
    scrape_interval: 5s

Built-in Metrics

Metrics collected by Adonis5-prometheus middleware

Type	Name	Description
Histogram	`adonis_http_request_durations`	Total time each HTTP requests takes.
Gauge	`adonis_uptime_metrics`	Uptime performance of the application (1 = up, 0 = down)
Counter	`adonis_throughput_metrics`	No. of request handled.

To enable them, simply register the CollectPerformanceMetrics as the first item in the start/kernel.ts:

Server.middleware.register([
  // Make it first in the list for reliable metrics.
  () => import('@ioc:Adonis/Prometheus/Middlewares/CollectPerformanceMetrics'),
  () => import('@ioc:Adonis/Core/BodyParser'),
  ...
])

Verify if the metrics are enabled in the config/prometheus.ts file. You can also configure the metrics there.

Custom Metrics

// Register your custom metrics in the separate file you want.
export const OrderMetric = new Prometheus.Counter({
  name: 'sent_orders',
  help: 'Total Orders Sent',
})

// OrderController.ts
import { OrderMetric } from 'App/Metrics'

export default class OrderController {
  public async store({ request }: HttpContextContract) {
    const order = await request.validate({ schema: OrderSchema })

    // ...
    OrderMetric.inc()
    // ...
  }
}

When hitting {{host}}/metrics you will now get the following:

# HELP send_orders Total Orders Sent
# TYPE send_orders counter
sent_orders 2

Grafana Dashboard

A basic ready to use dashboard is available in the grafana folder. Grafana 8 is required to be able to import the dashboard correctly, otherwise you'll have to tinker a bit to make it work. It includes :

Process CPU usage
Event loop lag
Node.JS version
Requests by second
Request volume rate by URL
Average response time
Response error rate by URL

To be fully functional, you need to enable systemMetrics, httpMetric and throughputMetric in the config/prometheus.ts file.

Documentation

This library is a wrapper for prom-client. The prom-client object can be imported with import Prometheus from '@ioc:Adonis/Prometheus'. Check out the documentation for more information.

adonis5-prometheus