Server
PM2
What is PM2?
PM2 is a production process manager for Node.js applications with a built-in load balancer. It allows you to keep applications alive forever, reload them without downtime, and facilitate common system admin tasks.
Optimized for Node.js; supports clustering and load balancing for better utilization of multi-core CPUs.
Install PM2
> npm install pm2@latest -g
Verify Installation
> pm2 --version
Use PM2
Switch to your project directory and run the following commands:
> pm2 start npm --name "project_name" -- start
With a specific port:
> PORT=3001 pm2 start npm --name "another_project_name" -- start
Run Your App in Cluster Mode
> pm2 start npm --name "project_name" -- start -i max
max means that PM2 will auto detect the number of available CPUs and run as many processes as possible.
Check Running Processes
> pm2 list
Enable Auto-Start
> pm2 startup
You should know!
After running the above command, you will see a command to run on your terminal to enable auto-start.
Save Current Processes
> pm2 save
If you need to remove init script via:
> pm2 unstartup systemd
Alternatively, you can remove the init script manually. The startup script is usually located in the systemd service folder /etc/systemd/system. You can identify the service name, which should be something like pm2-ubuntu.service.
> sudo systemctl stop pm2-ubuntu
> sudo systemctl disable pm2-ubuntu
> sudo rm /etc/systemd/system/pm2-ubuntu.service
> sudo systemctl daemon-reload
Utility Commands
Monitor CPU/Memory Usage
> pm2 monit
Restart All Processes
> pm2 restart all
Stop All Processes
> pm2 stop all
Delete All Processes
> pm2 delete all
Check Logs
> pm2 logs project_name
Clear Logs
> pm2 flush