Redis Clone in C++

Redis is an open source in-memory key value database which is widely used in applications requiring caching, session storage, rate limiting, and real-time applications due to it's very high read/write performance. In this project, I habe implemented a Redis inspired clone built in C++. It features core database functionality like TCP client-server communication, command parsing, persistence, TTL expiration, multithreading, and thread safe in-memory storage.

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Demo

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Features

• TCP socket server
• Multithreaded client handling
• In-memory key-value store
• Persistence to disk (dump.rdb)
• TTL expiration support
• Thread-safe operations with mutex locks
• Local benchmarking script

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Supported Commands

PING
SET key value
GET key
DEL key
EXPIRE key seconds
EXISTS key
KEYS

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Build

mkdir build
cd build
cmake ..
make
./redis_clone

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Connect to Server

nc localhost 6379

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Benchmark

Run local throughput benchmark:

python3 benchmark.py

Example result:

Requests: 1000
Elapsed: 0.2278s
Requests/sec: 4389.49

Achieved 4,000+ requests/sec in local testing.

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Architecture

Client
   ↓
TCP Socket Server
   ↓
Command Parser
   ↓
Database Engine
   ↓
Persistence Layer

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Tech Stack

• C++20
• CMake
• POSIX sockets
• std::thread multithreading
• mutex synchronization
• unordered_map in-memory storage

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Future Improvements

• LRU eviction policy
• Publish/Subscribe messaging
• Replication support
• Additional benchmarking and unit tests