Error handling in clients in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to catch errors when connecting to Redis.

Redis

try {
  const client = redis.createClient();
  await client.connect();
} catch ([1]) {
  console.error('Connection error:', [1]);
}

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

Aerror

Berr

Cexception

De

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name not declared in the catch block.

Leaving the catch parentheses empty.

The catch block receives the error object, commonly named err to handle connection errors.

2fill in blank

medium

Complete the code to listen for Redis client error events.

Redis

client.on('error', function([1]) {
  console.log('Redis error:', [1]);
});

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

Aerror

Bexception

Ce

Derr

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name different from the one used inside the function.

Not passing any parameter to the function.

The error event handler receives an error object, commonly named err.

3fill in blank

hard

Fix the error in the code to properly handle Redis command errors.

Redis

client.get('key', function(err, reply) {
  if ([1]) {
    console.error('Command error:', err);
    return;
  }
  console.log('Value:', reply);
});

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

Aerr

Berror

Creply

Dexception

Attempts:

3 left

💡 Hint

Common Mistakes

Checking the reply instead of the error.

Using a wrong variable name for the error.

Check if err exists to detect command errors before using the reply.

4fill in blank

hard

Fill both blanks to handle Redis connection errors and close the client.

Redis

client.on('error', function([1]) {
  console.error('Redis error:', [1]);
  client.[2]();
});

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

Aerr

Berror

Cquit

Ddisconnect

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong parameter names in the error handler.

Calling a non-existent method to close the client.

The error event handler receives err. To close the client, call client.quit().

5fill in blank

hard

Fill all three blanks to retry connecting on error with a delay.

Redis

client.on('error', async function([1]) {
  console.error('Error:', [1]);
  await new Promise(resolve => setTimeout(resolve, [2]));
  await client.[3]();
});

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

Aerr

B1000

Cconnect

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names or delay values.

Calling the wrong method to reconnect.

Use err as the error parameter, wait 1000 milliseconds, then call client.connect() to retry.