Node.js Apm Setup

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Prerequisites

• To monitor APM data on dashboard, Middleware Host agent needs to be installed.
• You can refer this demo project to refer use cases of APM.

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Step 1 : Install NPM package

Run this in your terminal

npm install @middleware.io/node-apm --save

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Step 2 : Prepend APM script

Add these lines given below at the very start of your project.

const tracker = require('@middleware.io/node-apm');
tracker.track({
    projectName: "your-project-name",
    serviceName: "your-service-name",
});

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Collect Node.js specific metrics

The metrics collection starts automatically as soon as you complete Step 2

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Distributed Tracing

All your APIs are auto-instrumented as soon as you complete Step 2

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Add custom logs

tracker.info('Info sample');
tracker.warn('Warning sample');
tracker.debug('Debugging Sample');
tracker.error('Error Sample');

If you want to add stack trace along with the error log, you can follow the snippet as given below

tracker.error(new Error('Error sample with stack trace'));

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Note for APM inside Kubernetes

If you are using APM in a Kubernetes cluster make sure to follow these 2 steps:

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Step 1 : Find your Middleware Service namespace

For older setup, your “mw-service” can be inside mw-agent-ns-{FIRST-5-LETTERS-OF-API-KEY} namespace

For newer setup, we simplified the namespace name to mw-agent-ns

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Step 2 : Set this ENV variable in your application deployment YAML

MW_AGENT_SERVICE=mw-service.NAMESPACE.svc.cluster.local

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Error Handling

If you want to record exception in traces then you can use track.errorRecord(error) method.

 app.get('/error', function (req, res) {
    try{
        throw new Error('oh error!');
    }catch (e) {
       track.errorRecord(e)
    }
    res.status(500).send("wrong");
});