Redis as cache vs data store vs message broker - Hands-On Comparison

Using Redis as Cache, Data Store, and Message Broker

📖 Scenario: You are building a simple web application that needs to store user session data, cache frequently accessed product information, and send notifications between different parts of the app.Redis can help with all these tasks by acting as a cache, a data store, and a message broker.

🎯 Goal: Learn how to use Redis for three common roles: caching data, storing persistent data, and sending messages between services.You will write Redis commands step-by-step to set up each role.

📋 What You'll Learn

Create a Redis key-value pair to store user session data (data store)

Create a Redis key-value pair to cache product information (cache)

Set an expiration time for the cached product data

Use Redis Pub/Sub commands to send and receive a notification message (message broker)

💡 Why This Matters

🌍 Real World

Web applications often need fast access to session data, quick caching of product info, and real-time notifications. Redis supports all these needs efficiently.

💼 Career

Understanding Redis roles helps backend developers, DevOps engineers, and system architects build responsive and scalable systems.

1

Store user session data in Redis

Use the Redis command SET to create a key called session:user123 with the value {"username":"alice","role":"admin"}. This simulates storing user session data persistently.

Redis

# Use SET command to store session data
# Your code here

Need a hint?

Use SET key value to store data in Redis.

2

Cache product information with expiration

Use the Redis command SET with the EX option to create a key called cache:product:456 with the value {"name":"Coffee Mug","price":12.99} that expires after 60 seconds. This simulates caching product data temporarily.

Redis

SET session:user123 "{\"username\":\"alice\",\"role\":\"admin\"}"
# Use SET with EX to cache product data with expiration
# Your code here

Need a hint?

Use SET key value EX seconds to set a key with expiration.

3

Publish a notification message

Use the Redis command PUBLISH to send the message "New order received" to the channel notifications. This simulates sending a message between services.

Redis

SET session:user123 "{\"username\":\"alice\",\"role\":\"admin\"}"
SET cache:product:456 "{\"name\":\"Coffee Mug\",\"price\":12.99}" EX 60
# Use PUBLISH to send a notification message
# Your code here

Need a hint?

Use PUBLISH channel message to send messages in Redis Pub/Sub.

4

Subscribe to the notification channel

Use the Redis command SUBSCRIBE to listen to the notifications channel. This simulates receiving messages sent by other parts of the app.

Redis

SET session:user123 "{\"username\":\"alice\",\"role\":\"admin\"}"
SET cache:product:456 "{\"name\":\"Coffee Mug\",\"price\":12.99}" EX 60
PUBLISH notifications "New order received"
# Use SUBSCRIBE to listen to notifications
# Your code here

Need a hint?

Use SUBSCRIBE channel to listen for messages in Redis Pub/Sub.