Why pub/sub enables real-time messaging in Redis - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to publish a message to a channel.

Redis

PUBLISH [1] "Hello, world!"

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

Aclient

Bsubscribe

Cmessage

Dnews

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'subscribe' instead of a channel name

Using 'message' as channel name which is too generic

The PUBLISH command sends a message to a specific channel, here the channel name is news.

2fill in blank

medium

Complete the code to subscribe to a channel for receiving messages.

Redis

SUBSCRIBE [1]

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

Anews

Bpublish

Cclient

Dmessage

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'publish' which is a command, not a channel

Using 'client' which is unrelated

The SUBSCRIBE command listens to messages sent to the news channel.

3fill in blank

hard

Fix the error in the command to subscribe to multiple channels.

Redis

SUBSCRIBE [1]

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

Anews,sports

Bnews sports

Cnews;sports

Dnews:sports

Attempts:

3 left

💡 Hint

Common Mistakes

Using commas or semicolons to separate channels

Using colons which is invalid

To subscribe to multiple channels, list them separated by spaces without commas or other punctuation.

4fill in blank

hard

Fill both blanks to publish a message and subscribe to the same channel.

Redis

PUBLISH [1] "Update available"
SUBSCRIBE [2]

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

Aupdates

Bnews

Dalerts

Attempts:

3 left

💡 Hint

Common Mistakes

Using different channel names for publish and subscribe

Using unrelated channel names

Both publishing and subscribing must use the same channel name to enable real-time messaging.

5fill in blank

hard

Fill all three blanks to subscribe to channels and publish a message to one.

Redis

SUBSCRIBE [1] [2]
PUBLISH [3] "System rebooted"

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

Asystem

Balerts

Dupdates

Attempts:

3 left

💡 Hint

Common Mistakes

Using commas or other separators in SUBSCRIBE

Publishing to a channel not subscribed to

You subscribe to multiple channels by listing them separated by spaces. Publishing uses one of those channels.