Node.js Process Management

Process management refers to how Node.js handles:

• The running process

• Environment variables

• Process information

• Exiting the app

• Managing multiple worker processes

• Background/production process managers (PM2, Forever, Nodemon)

Node.js exposes process-related features through the global process object and external tools.

✅ 1. The process Object

process is a global object that provides information and control over the current Node.js process.

No import needed.

📌 2. Getting Process Information

Process ID

Platform

Node version

Working directory

Memory usage

📌 3. Environment Variables (process.env)

Used for configuration and secrets.

Example:

In Node:

📌 4. Access Command-Line Arguments

Example:

Output:

📌 5. Exiting the Process

Normal Exit:

Exit With Code:

Exit codes:

• 0 → success

• 1 → error

📌 6. Process Events

on exit

on uncaughtException

on unhandled promise rejection

📌 7. Process.nextTick()

Executes a callback before the event loop continues.

📌 8. High-Level Process Management: Clustering

Node.js is single-threaded, but you can use child processes or the cluster module to use all CPU cores.

Example (Cluster):

📌 9. Child Processes (Multiple Processes)

Child processes allow running external commands or multiple Node programs.

📌 10. Running Node Apps in Production (PM2)

PM2 is the most used Node process manager.

Install:

Start app:

View running processes:

Restart:

Stop:

Monitor:

PM2 ensures:

• Auto-restart on crash

• Load balancing

• Log management

• Daemon mode

📌 11. Other Process Managers

Nodemon (for dev auto-restart)

Forever (older tool)

⭐ Summary