Logging and Monitoring Tools

Introduction

Logging and monitoring are essential components of any modern web application. They allow developers to track application performance, manage errors, and understand user interactions.

Key Concepts

• Logging: The process of recording events that occur during the execution of an application.
• Monitoring: The continuous observation of application performance and health.
• Metrics: Quantitative measurements used to assess system performance.
• Alerts: Notifications triggered by specific conditions in your application.

Logging Tools

const winston = require('winston');

const logger = winston.createLogger({
    level: 'info',
    format: winston.format.json(),
    transports: [
        new winston.transports.File({ filename: 'combined.log' })
    ]
});

logger.info('Hello, this is a logging message!');

Monitoring Tools

const express = require('express');
const promClient = require('prom-client');

const app = express();
const collectDefaultMetrics = promClient.collectDefaultMetrics;
collectDefaultMetrics();

app.get('/', (req, res) => {
    res.send('Hello World!');
});

app.listen(3000, () => {
    console.log('Server running on http://localhost:3000');
});

Best Practices

• Use a structured logging format (e.g., JSON).
• Implement log rotation to manage log file sizes.
• Set up alerts for critical errors and performance issues.
• Regularly review logs to identify patterns and anomalies.

FAQ