Redis
Fast, in-memory data structure store for databases, caches, and message brokers
⚡ What is Redis?
Redis (Remote Dictionary Server) is a fast, open-source, in-memory data structure store that can be used as a database, cache, and message broker. It supports various data structures like strings, hashes, lists, sets, sorted sets, and more, all stored in memory for extremely fast access.
Built for performance, Redis can handle millions of operations per second with sub-millisecond latency. Its versatility makes it popular for caching, session storage, real-time analytics, and messaging via its built-in Pub/Sub capabilities.
Redis operates primarily as an in-memory database but provides persistence options to disk, combining the speed of memory-based operations with the durability of traditional databases when needed.
🚀 Core Features
In-Memory Performance
All data stored in RAM for microsecond-level access times and millions of operations per second.
Rich Data Types
Native support for strings, lists, sets, hashes, sorted sets, bitmaps, and more.
Persistence Options
RDB snapshots and AOF logging for data durability and recovery.
Pub/Sub Messaging
Built-in publish-subscribe capabilities for real-time messaging and event distribution.
Atomic Operations
All operations are atomic, ensuring data consistency in concurrent environments.
Clustering & HA
Built-in clustering, replication, and high availability features for production deployments.
🗃️ Data Structures
Strings
Binary-safe strings up to 512MB
GET key
INCR counter
Lists
Ordered collections of strings
RPOP list
LRANGE list 0 -1
Sets
Unordered collections of unique strings
SISMEMBER set "member"
SUNION set1 set2
Hashes
Field-value pairs (like objects)
HGET hash field
HGETALL hash
Sorted Sets
Sets ordered by score values
ZRANGE zset 0 -1
ZRANK zset "first"
Streams
Append-only log data structure
XREAD STREAMS stream 0
XGROUP CREATE stream group
🔌 RESP (REdis Serialization Protocol)
RESP is the simple, text-based protocol used for communication with a Redis server. It's designed to be human-readable while remaining efficient for high-performance applications. RESP supports different data types and provides a standardized way for clients to interact with Redis.
The protocol is stateless and connection-oriented, using TCP connections between clients and the Redis server. Each command and response follows a specific format that makes it easy to implement Redis clients in any programming language.
Protocol Features
- • Simple: Easy to implement and debug
- • Fast: Minimal parsing overhead
- • Human-readable: Text-based format
- • Binary-safe: Supports binary data
Data Type Prefixes
Example RESP Communication
📡 Messaging Capabilities
Pub/Sub Pattern
Redis provides built-in publish-subscribe messaging for real-time communication between applications.
List-based Queues
Use Redis lists as simple message queues with blocking operations for efficient message processing.
Redis Streams (Advanced Messaging)
Redis Streams provide a more sophisticated messaging solution with features like consumer groups, message acknowledgments, and message history.
Key Features:
- • Append-only log structure
- • Consumer groups for load balancing
- • Message acknowledgments
- • Message history and replay
- • Range queries by time or ID
Example Commands:
🎯 Common Use Cases
Caching & Performance
- • Application Cache: Store frequently accessed data in memory for fast retrieval
- • Session Storage: Web application session data with automatic expiration
- • Page Caching: Store rendered HTML pages for faster web responses
- • API Response Cache: Cache expensive API calls and database queries
Real-time Applications
- • Chat Applications: Real-time messaging with pub/sub patterns
- • Live Analytics: Real-time metrics and dashboard updates
- • Gaming Leaderboards: Sorted sets for rankings and scores
- • Event Streaming: Process and route events in real-time