Express.js Course
Express.js
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Beginner

PM2 Process Manager

Definition

If an Express app crashes in production due to a bug, the server dies and users get 502 errors. PM2 is a production process manager that keeps your app alive forever by automatically restarting it if it crashes. It also handles cluster mode effortlessly.

Explain Like I'm New

If an Express app crashes in production due to a bug, the server dies and users get 502 errors.

Terminal Output

bash / terminal
$ npm install pm2 -g $ pm2 start server.js --name "my-api" // PM2 will now run the app in the background and auto-restart it on failure.

Interview Questions

basic

  • What is the primary purpose of PM2 Process Manager in Express.js?
  • How do you initialize PM2 Process Manager?

intermediate

  • How does PM2 Process Manager integrate with other middleware components?
  • Can you explain a common use case for PM2 Process Manager?

advanced

  • What are the performance implications of PM2 Process Manager in a high-traffic production application?
  • How would you debug issues related to PM2 Process Manager?

trick

  • Is it possible to achieve the same result as PM2 Process Manager without using Express?

Flash Cards

Question

Define PM2 Process Manager in your own words.

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Answer

If an Express app crashes in production due to a bug, the server dies and users get 502 errors.

Question

When should you avoid using PM2 Process Manager?

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Answer

It depends on the specific architectural requirements and performance bottlenecks of your application. Overusing it can sometimes lead to tightly coupled code.