Author: saqibkhan

Tip:

Properly handle uncaught exceptions and unhandled promise rejections to prevent application crashes.

Example:

javascriptCopy codeprocess.on('uncaughtException', (err) => {
console.error('Uncaught Exception:', err);
// Perform cleanup and exit or restart application
});

process.on('unhandledRejection', (reason, promise) => {
console.error('Unhandled Rejection:', reason);
// Perform cleanup and exit or restart application
});

Reason: Helps in managing errors gracefully and avoiding abrupt crashes, though it is often better to fix the root causes of these issues.

Tip:

Implement graceful shutdown procedures to ensure ongoing requests are completed before exiting.

Example:

javascriptCopy codeconst server = require('http').createServer((req, res) => {
res.end('Hello World');
});

server.listen(3000);

function shutdown() {
server.close(() => {
    console.log('Server closed');
    process.exit(0);
});
setTimeout(() => {
    console.error('Forcing shutdown');
    process.exit(1);
}, 10000); // Force shutdown after 10 seconds
}

process.on('SIGTERM', shutdown);
process.on('SIGINT', shutdown);

Reason: Ensures that active connections are properly closed and resources are released before the application exits.

Tip:

Use process.hrtime() for accurate timing measurements in your application.

Example:

javascriptCopy codeconst start = process.hrtime();
// Code to measure
const end = process.hrtime(start);
console.log(Execution time: ${end[0]} seconds and ${end[1] / 1e6} milliseconds);

Reason: Provides high-resolution time measurements, useful for performance profiling and benchmarking.

Tip:

Use the --trace-warnings flag to get detailed stack traces for warnings, which can help diagnose issues more effectively.

Example:

bashCopy codenode --trace-warnings your-script.js

Reason: Provides more context for warnings that could indicate potential issues in your code.

Tip:

Regularly audit and update your dependencies to avoid security vulnerabilities and ensure compatibility.

Example:

bashCopy code# Audit dependencies for vulnerabilities
npm audit

# Update outdated dependencies
npm update

Reason: Keeping dependencies up-to-date helps mitigate security risks and ensures compatibility with newer versions of Node.js.

Tip:

Use the cluster module to take advantage of multi-core systems by creating child processes that share the same server port.

Example:

javascriptCopy codeconst cluster = require('cluster');
const http = require('http');
const numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
console.log(Master ${process.pid} is running);
for (let i = 0; i < numCPUs; i++) {
    cluster.fork();
}
cluster.on('exit', (worker, code, signal) => {
    console.log(Worker ${worker.process.pid} died);
});
} else {
http.createServer((req, res) => {
    res.writeHead(200);
    res.end('Hello, World!\n');
}).listen(8000);
console.log(Worker ${process.pid} started);
}

Reason: Clustering enables better CPU utilization and can handle more concurrent connections by distributing the load.

Tip:

Use the worker_threads module to handle CPU-bound tasks by running JavaScript code in parallel threads.

Example:

javascriptCopy codeconst { Worker } = require('worker_threads');

function runWorker(taskData) {
return new Promise((resolve, reject) => {
    const worker = new Worker('./worker.js', { workerData: taskData });
    worker.on('message', resolve);
    worker.on('error', reject);
    worker.on('exit', (code) => {
        if (code !== 0) reject(new Error(Worker stopped with exit code ${code}));
    });
});
}

Reason: worker_threads allow for parallel processing and can improve performance for CPU-intensive operations.

Tip:

Use streams to handle large files or data in chunks rather than loading everything into memory.

Example:

javascriptCopy codeconst fs = require('fs');
const zlib = require('zlib');

const readStream = fs.createReadStream('largeFile.txt');
const writeStream = fs.createWriteStream('largeFile.gz');
const gzip = zlib.createGzip();

readStream.pipe(gzip).pipe(writeStream);

Reason: Streams help manage memory efficiently and improve performance by processing data incrementally.

Tip:

Transition from callback-based code to async/await to make asynchronous code more readable and maintainable.

Example:

javascriptCopy codeconst fs = require('fs').promises;

async function readFile(filePath) {
try {
    const data = await fs.readFile(filePath, 'utf8');
    return data;
} catch (err) {
    console.error('Error reading file:', err);
}
}

Reason: async/await simplifies asynchronous code by avoiding callback hell and making error handling more straightforward.