Health check endpoints in Node.js - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a health check endpoint in a web service?

A health check endpoint is a special URL in a web service that returns a simple response to show the service is running and healthy.

beginner

Why are health check endpoints important in Node.js applications?

They help monitoring tools and load balancers know if the app is working well or needs restarting, improving reliability.

beginner

Which HTTP status code is commonly returned by a healthy health check endpoint?

HTTP 200 OK means the service is healthy and responding correctly.

beginner

How can you implement a simple health check endpoint in Express.js?

Add a route like app.get('/health', (req, res) => res.send('OK')) that returns a 200 status and a simple message.

intermediate

What extra checks might a health check endpoint perform besides just responding?

It can check database connections, external services, or disk space to confirm the app is fully healthy.

What HTTP status code should a healthy health check endpoint return?

A 500 Internal Server Error

B 404 Not Found

C 302 Redirect

D 200 OK

A healthy endpoint returns 200 OK to show the service is running fine.

Which Node.js framework is commonly used to create health check endpoints?

A Express.js

B React

C Vue

D Angular

Express.js is a popular Node.js framework for building web servers and endpoints.

What is the main purpose of a health check endpoint?

A To serve the main website content

B To show the app is running and healthy

C To handle user login

D To store user data

Health check endpoints are for monitoring app health, not for user features.

Which of these is NOT a typical check in a health check endpoint?

A User password validation

B External API availability

C Disk space availability

D Database connection status

User password validation is unrelated to health checks.

How often should health check endpoints be called by monitoring tools?

A Only once when the app starts

B Never, they are manual checks

C Regularly, like every few seconds or minutes

D Only when errors occur

Regular calls help detect problems quickly.

Explain what a health check endpoint is and why it is useful in Node.js applications.

Think about how servers tell if they are okay.

Describe how you would create a simple health check endpoint using Express.js.

Focus on the route and response.