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