Distributed Cache

A multi-node in-memory cache system built in Go with LRU eviction, TTL expiration, and consistent hashing for efficient key distribution.

Features

• Consistent Hashing: Efficiently distributes keys across multiple cache nodes
• TTL Support: Automatic expiration of cached items
• LRU Eviction: Least Recently Used eviction policy when cache is full
• Docker Support: Easy deployment with Docker Compose
• HTTP API: Simple REST API for cache operations
• Load Balancing: Nginx for distributing requests
• Multiple Nodes: Scalable multi-node architecture

Architecture

The system consists of:

• Multiple cache server nodes
• Consistent hash ring for key distribution
• Nginx load balancer
• HTTP handlers for GET/SET/DELETE operations

Getting Started

Prerequisites

• Go 1.16 or higher (for local development)
• Docker and Docker Compose (for containerized deployment)

Running with Docker Compose

1. Clone the repository:

git clone https://github.com/jknate/distributed-cache.git
cd distributed-cache

2. Start the cache cluster:

docker-compose up

This will start multiple cache nodes and an Nginx load balancer.

Local Development

1. Build the project:

go build -o cache-server main.go

2. Run a cache node:

./cache-server

API Usage

Set a value

curl -X POST http://localhost/set \
  -H "Content-Type: application/json" \
  -d '{"key": "mykey", "value": "myvalue", "ttl": 3600}'

Get a value

curl http://localhost/get?key=mykey

Delete a value

curl -X DELETE http://localhost/delete?key=mykey

Configuration

• Modify docker-compose.yml to adjust the number of cache nodes
• Update nginx.conf for load balancer settings
• Configure TTL and cache size in the cache initialization

Project Structure

• main.go - Entry point and server setup
• cache/ - Cache implementation with LRU and TTL
• hashring/ - Consistent hashing implementation
• handlers/ - HTTP request handlers
• Dockerfile - Container image definition
• docker-compose.yml - Multi-container orchestration
• nginx.conf - Load balancer configuration