Redis Study Notes

Cache Invalidation Patterns

How to keep Redis-cached data correct as the underlying source changes, covering explicit invalidation, TTL trade-offs, and Pub/Sub-based invalidation across m…

Caching Strategies with Redis

A practical guide to the core caching patterns — cache-aside, write-through, and write-behind — used to speed up applications with Redis, plus how to pick sane…

Hashes in Redis

Learn how Redis Hashes model field-value objects efficiently, covering HSET/HGET, partial updates, memory-efficient small-hash encoding, and common object-mode…

Installing and Connecting to Redis

A practical guide to installing Redis locally or via Docker, understanding the core config file settings, and connecting to it from client libraries.

Key Expiration and TTL

Learn how Redis lets keys expire automatically using TTLs, and how expiration is implemented internally through lazy and active mechanisms.

Lists in Redis

Understand Redis Lists as ordered, linked-list-backed collections, covering push/pop operations, blocking reads for queues, and range-based trimming.

Pipelining in Redis

How Redis pipelining collapses many network round trips into one for bulk operations, how it differs from MULTI/EXEC transactions, and when it can't help.

Redis as a Session Store

How Redis centralizes web session state across multiple application servers, from modeling sessions as hashes with TTLs to session security and scaling with Se…

Redis Cluster Explained

How Redis Cluster shards data across multiple nodes using hash slots, and how it handles failover and multi-key operations.

Redis Data Persistence: RDB and AOF

How Redis persists in-memory data to disk using RDB snapshots and the AOF log, and how to choose (or combine) the right strategy for your workload.

Redis Eviction Policies

How Redis decides which keys to remove when memory is full, the available eviction policies, and how to choose the right one for your workload.

Redis Interview Questions

A study guide covering the Redis concepts most commonly probed in interviews: data structures, persistence, replication, and scaling tradeoffs.

Redis Key Naming Conventions

Understand why disciplined key naming matters in Redis and how to design namespaces that scale across teams and services.

Redis Memory Optimization

Techniques for minimizing Redis's RAM footprint, from choosing efficient encodings and bucketing strategies to compression, serialization, and maxmemory tuning.

Redis Persistence Tradeoffs

A practical comparison of RDB snapshots and AOF logging in Redis, and how to choose or combine them based on your durability and performance needs.

Redis Pub/Sub

Learn how Redis's publish/subscribe messaging model works, its fire-and-forget delivery guarantees, and when to reach for Streams instead.

Redis Quick Reference

A condensed cheat sheet of the most-used Redis commands across data types, key management, and server administration.

Redis Replication

How Redis copies data from a primary to one or more replicas for read scaling and failover readiness, and the consistency tradeoffs that come with it.

Redis Security Basics

Core practices for securing a Redis deployment: authentication, ACLs, TLS encryption, and network hardening.

Redis Sentinel for High Availability

How Redis Sentinel monitors a primary/replica deployment, detects failures, and orchestrates automatic failover without a cluster topology.

Redis Streams

How Redis Streams model an append-only log, and how XADD, consumer groups, and trimming work together for durable event processing.

Redis Transactions: MULTI/EXEC

Understand how Redis groups commands into atomic transactions using MULTI, EXEC, DISCARD, and optimistic locking with WATCH.

Redis Use Cases

A tour of the most common production use cases for Redis: caching, session storage, real-time leaderboards, rate limiting, and pub/sub messaging.

Redis with Node.js or Python

How to connect to, query, and manage Redis connections from Node.js (node-redis/ioredis) and Python (redis-py) application code.