My solution to "Build Your Own Redis" Challenge. This is a Redis clone that I built. It implements part of the Redis protocol (RESP 2) and supporting several commands.

Features

• Basic Commands: GET, SET, PING
• Concurrency: Supports multiple concurrent clients
• Persistence: Loads RDB files and serves the content
• Replication:
  • Performs replication handshake
  • Propagates commands to replicas
  • Supports the WAIT command for synchronization of replicas
• Latency of GET and SET commands are similar to original Redis server! No libraries used.

Architecture

• Uses an event loop
• Runs on a single thread

Usage

make build
./build/redis

Send messages using redis-cli ping. Try other commands.

To run a replica run:

./build/redis --replicaof 6379

Technical Deep Dives

• Implemented binary protocol parsing
• Built a non-blocking I/O system
• Managed concurrent client connections
• Used my own hash map: https://nullprogram.com/blog/2023/09/30/
• Used memory arena for easier memory management: https://nullprogram.com/blog/2023/09/27/
• Used custom string type to avoid limitations of C strings: https://nullprogram.com/blog/2023/10/08/
• Created a master-replica synchronization mechanism
• Handled data persistence with RDB files

What I Learned

• Network programming and protocol implementation
• Async programming in C
• Distributed systems concepts through replication
• High-performance tcp server design
• Implemented a hash map in C
• Using my custom allocator