How can I implement connection pooling in Node.js with MySQL?

How can I implement connection pooling in Node.js with MySQL?

You can use the mysql or mysql2 package in Node.js to implement connection pooling. First, install the package using npm.

What code do I need to set up the pool?

Here's a basic example:

const mysql = require('mysql2');

const pool = mysql.createPool({
  host: 'localhost',
  user: 'root',
  password: 'password',
  database: 'test',
  waitForConnections: true,
  connectionLimit: 10,
  queueLimit: 0
});

How do I query the database using the pool?

You can use the getConnection method to get a connection from the pool and then execute your query:

pool.getConnection((err, connection) => {
  if (err) throw err; // not connected!
  connection.query('SELECT * FROM users', (error, results) => {
    connection.release(); // return the connection to the pool
    if (error) throw error;
    console.log(results);
  });
});

What happens if the connection fails?

If a connection fails, the error will be passed to the callback function. You should handle it appropriately, possibly by retrying or logging the error.