Performance monitoring basics in Express - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is performance monitoring in software applications?

Performance monitoring is the process of tracking how well an application runs, including speed, responsiveness, and resource use, to ensure it works smoothly.

beginner

Name two common metrics tracked in performance monitoring.

Two common metrics are response time (how fast the app replies) and CPU usage (how much processing power the app uses).

beginner

Why is monitoring response time important in an Express app?

Because it shows how quickly the server answers requests, helping find delays that can make users wait or leave.

intermediate

What tool can you use to monitor performance in an Express.js application?

You can use tools like New Relic, PM2, or built-in Node.js modules like 'perf_hooks' to monitor performance.

beginner

How does logging help in performance monitoring?

Logging records events and errors, helping you spot when and where performance problems happen.

Which metric shows how long it takes for a server to respond to a request?

A Response time

B CPU usage

C Memory allocation

D Disk space

Response time measures the delay between a request and the server's reply.

What is a common tool to monitor Node.js or Express app performance?

A Photoshop

B PM2

C Excel

D Slack

PM2 is a process manager that also provides performance monitoring for Node.js apps.

Why monitor CPU usage in an Express app?

A To track user clicks

B To measure internet speed

C To count database records

D To check how much processing power the app uses

CPU usage shows how much of the processor's power the app consumes.

What does logging NOT help with in performance monitoring?

A Increasing server speed automatically

B Tracking events

C Finding errors

D Spotting performance issues

Logging helps find problems but does not automatically improve speed.

Which Node.js module can help measure performance timings?

A path

B http

C perf_hooks

D fs

'perf_hooks' provides performance timing APIs in Node.js.

Explain why performance monitoring is important for an Express.js application.

Think about what happens if the app is slow or crashes.

List common metrics and tools used for performance monitoring in Express apps.

Consider what you measure and what helps you measure it.