This video shows you how to use connection pooling in MySQL with Node.js. Connection Pooling leads to two-fold increase in the performance of the application(According to benchmarks).
It does by maintaining a cache of database connection that can be used again and again for executing commands/queries, thus by saving time and resources required for creating a new connection for every user.
[+] Node.js MySQL tutorial : https://goo.gl/2xCt9k
[+] MySQL Module : https://www.npmjs.com/package/mysql