moleculer-prometheus

Moleculer metrics module for Prometheus.

Features

• collect default Node.js metrics.
• measure service calls.
• support custom metrics.
• Grafana dashboard example.

Install

$ npm install moleculer-prometheus

Usage

// services/metrics.prometheus.service.js

const PromService = require("moleculer-prometheus");

module.exports = {
    mixins: [PromService],
    settings: {
        port: 3030,
        collectDefaultMetrics: true,
        timeout: 5 * 1000, 
    }
};

// moleculer.config.js
module.exports = {
    // ...
    metrics: true,
    // ...
}

Add custom metric

// services/metrics.prometheus.js
const PromService = require("moleculer-prometheus");

module.exports = {
    mixins: [PromService],
    settings: {
        metrics: {
           "custom_value": { type: "Gauge", help: "Moleculer Prometheus custom metric" } 
        } 
    }
};

Broadcast a metrics.update event to set the metric value

broker.broadcast("metrics.update", {
    name: "custom_value",
    method: "set",
    value: Math.round(Math.random() * 100)
});

Settings

| Property | Type | Default | Description | | -------- | ---- | ------- | ----------- | | port | Number | 3030 | Exposed HTTP port. | | collectDefaultMetrics | Boolean | true | Enable to collect default metrics. | | timeout | Number | 10000 | Timeout option for 'collectDefaultMetrics' in milliseconds. | | metrics | Object | {} | Metric definitions. |

Default Moleculer metrics

| Name | Type | Labels | Description | | ---- | ---- | ------ | ----------- | | moleculer_nodes_total | Gauge | - | Moleculer nodes count | | moleculer_services_total | Gauge | - | Moleculer services count | | moleculer_actions_total | Gauge | - | Moleculer actions count | | moleculer_events_total | Gauge | - | Moleculer event subscription count | | moleculer_nodes | Gauge | nodeID, type, version, langVersion | Moleculer node list | | moleculer_action_endpoints_total | Gauge | action | Moleculer action endpoints | | moleculer_service_endpoints_total | Gauge | service, version | Moleculer service endpoints | | moleculer_event_endpoints_total | Gauge | event, group | Moleculer event endpoints | | moleculer_req_total | Counter | action, service, nodeID | Moleculer request count | | moleculer_req_errors_total | Counter | action, service, nodeID, errorCode, errorName, errorType | Moleculer request error count | | moleculer_req_duration_ms | Histogram | action, service, nodeID | Moleculer request durations |

Methods

update

Update a metric value.

Parameters

| Property | Type | Default | Description | | -------- | ---- | ------- | ----------- | | name | String | required | | | method | String | required | | | labels | Object | - | | | value | any | required | | | timestamp | any | required | |

Test

$ npm test

In development with watching

$ npm run ci

License

The project is available under the MIT license.

Contact

Copyright (c) 2016-2018 MoleculerJS