Key design patterns in Redis - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Cache Aside pattern in Redis?

Cache Aside is a design pattern where the application first checks Redis for data. If the data is missing, it loads from the database, stores it in Redis, then returns it. This helps keep Redis as a fast cache.

intermediate

Explain the Rate Limiting pattern using Redis.

Rate Limiting controls how often a user can perform an action. Redis uses counters with expiration to track requests per user, blocking requests that exceed limits within a time window.

beginner

What is the purpose of the Pub/Sub pattern in Redis?

Pub/Sub allows messages to be sent to multiple subscribers instantly. Publishers send messages to channels, and subscribers listening to those channels receive them in real-time.

intermediate

Describe the Leaderboards pattern in Redis.

Leaderboards use Redis sorted sets to keep scores ranked. Scores can be updated quickly, and top players retrieved efficiently, making it ideal for games or competitions.

advanced

How does the Distributed Lock pattern work in Redis?

Distributed Lock uses Redis keys with expiration to ensure only one process can access a resource at a time. It prevents conflicts in distributed systems by locking critical sections.

Which Redis data structure is best for implementing a leaderboard?

A Lists

B Hashes

C Sorted Sets

D Strings

Sorted Sets store members with scores and keep them ordered, perfect for leaderboards.

In the Cache Aside pattern, what happens if data is not found in Redis?

A Return an error immediately

B Delete the Redis cache

C Ignore the request

D Load data from the database, store it in Redis, then return it

The application loads data from the database, caches it in Redis, then returns it.

What does the Rate Limiting pattern in Redis typically use to track requests?

A Strings with expiration

B Counters with expiration

C Lists

D Hashes

Counters with expiration track how many requests a user makes in a time window.

What is the main benefit of using the Pub/Sub pattern in Redis?

A Real-time message delivery to multiple subscribers

B Sorting data

C Data backup

D Storing large files

Pub/Sub delivers messages instantly to all subscribers listening on a channel.

How does Redis help implement a Distributed Lock?

A By using keys with expiration to lock resources

B By storing user sessions

C By caching database queries

D By sorting data

Keys with expiration ensure only one process holds the lock at a time.

Describe how the Cache Aside pattern works in Redis and why it is useful.

Think about how Redis acts as a fast storage layer before the database.

Explain how Redis can be used to implement rate limiting for user requests.

Consider how Redis counters and expiration help track request frequency.