Graceful shutdown on errors in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to listen for uncaught exceptions and log the error.

Node.js

process.on('uncaughtException', (err) => {
  console.error('Uncaught Exception:', [1]);
});

Drag options to blanks, or click blank then click option'

Aerr.message

Berr

Cerror

Dexception

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name not defined in the callback.

Logging only err.message which hides stack trace.

The err object contains the error details. Logging err shows the full error.

2fill in blank

medium

Complete the code to listen for unhandled promise rejections and log the reason.

Node.js

process.on('unhandledRejection', (reason, promise) => {
  console.error('Unhandled Rejection at:', [1]);
});

Drag options to blanks, or click blank then click option'

Apromise

Bexception

Cerror

Dreason

Attempts:

3 left

💡 Hint

Common Mistakes

Logging the promise object instead of the reason.

Using undefined variable names.

The reason parameter contains why the promise was rejected. Logging it helps diagnose the issue.

3fill in blank

hard

Fix the error in the code to properly close the server on SIGINT signal.

Node.js

process.on('SIGINT', () => {
  console.log('SIGINT received, shutting down...');
  server.[1](() => {
    console.log('Server closed');
    process.exit(0);
  });
});

Drag options to blanks, or click blank then click option'

Aclose

Bshutdown

Cstop

Dend

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like shutdown or stop.

Not calling process.exit() after closing.

The server.close() method stops the server from accepting new connections and calls the callback when done.

4fill in blank

hard

Fill both blanks to log the error and exit the process with failure code.

Node.js

process.on('uncaughtException', (err) => {
  console.error('Error:', [1]);
  process.[2](1);
});

Drag options to blanks, or click blank then click option'

Aerr

Bexit

Cabort

Dthrow

Attempts:

3 left

💡 Hint

Common Mistakes

Using process.abort() which causes a core dump.

Not exiting the process after an uncaught exception.

Logging the error object err shows details. Using process.exit(1) exits with failure status.

5fill in blank

hard

Fill all three blanks to handle SIGTERM by closing the server and exiting cleanly.

Node.js

process.on('[1]', () => {
  console.log('Signal received, closing server...');
  server.[2](() => {
    console.log('Server closed, exiting.');
    process.[3](0);
  });
});

Drag options to blanks, or click blank then click option'

ASIGTERM

Bclose

Cexit

DSIGINT

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing SIGINT with SIGTERM.

Not calling process.exit() after closing the server.

SIGTERM is the termination signal. server.close() stops the server. process.exit(0) exits successfully.