USE Method

Measure Utilization, Saturation, and Errors inside the Node process.

process

Detailed Description

USE looks inside the Node process and host resources. CPU utilization, heap usage, RSS, event-loop delay, and errors tell you whether the runtime itself is saturated.

This method is useful after RED says the service is unhealthy. It helps separate app-level slowness from process-level pressure such as high CPU, memory growth, garbage collection, or event-loop backlog.

Mental Model

CPU utilization
heap/rss memory
event-loop lag
process errors

When To Use

->Understand whether Node is CPU, memory, or event-loop saturated
->Debug production slowdowns
->Compare instance sizes and worker counts

Tools: process.memoryUsage, process.cpuUsage, monitorEventLoopDelay

use-method.js

Live Editor

Output

Run code to see output...