Keep Your NodeJS App Alive With AWS EC2 & PM2

Let’s walkthrough one of many options for managing your NodeJS production processes

Quick Note:

This post can be used as a continuation of Deploying a NodeJS Application With AWS EC2, SSL, and a Load Balancer — Where I walked through the basics of getting a NodeJS application up and running EC2 and an application load balancer.

From the previous post, we have a small NodeJS application created on an EC2 instance; after installing node and express on the server and creating a index.js file to handle a couple of requests, I can run the server like so:

[ec2-user@ip-172-31-19-125 test-node-app]$ node index.js
Example app listening on port 8080

However, I don’t want my local computer to be in charge of managing the running process. What happens when I close my terminal or if my computer shuts down? Of course, I will lose my application process.

Enter: PM2

PM2 is a process management tool that runs on a daemon to keep your application running in the background 24/7 — To get your application up and running with PM2 is very straightforward; let’s walk through that now.

Once you have an EC2 instance running, SSH into the server, and run the following commands:

$ npm install pm2@latest -g
$ pm2 start index.js

You will see an output explaining what PM2 is and a few helpful commands:

Helpful Commands:

$ pm2 list — List all the running applications

$ pm2 show [name] — Display metadata for a specific process

$ pm2 monit — Monitor the resource usage of your application

$ pm2 stop [name] — Stop a specified application

$ pm2 delete [name] — To stop and delete an application

Now you’ll be able to access your NodeJS application 24/7! This walkthrough scratches the surface of PM2 and all of the capabilities it provides. You will likely want to build out a complete build.sh script that handles a more sophisticated PM2 start-up process but this work for us now. I will continue to post more information as my application develops and the requirements become more complex.

Alternatives to PM2 worth checking out:

Passenger — This service is an app server that efficiently runs and auto-manages your web apps. It also improves security, reliability, and scalability.

Systemd — This service offers on-demand starting of daemons, keeps track of processes using Linux control groups, maintains mount and automount points, and implements an elaborate transactional dependency-based service control logic.

Forever — A simple CLI tool ensuring that a given script runs continuously (i.e., forever). Note that this project currently entirely depends on the community to implement fixes and new features.