Key-Value-Cache - High-Performance Key-Value Store

Overview

Key-Value-Cache is a high-performance in-memory key-value store built with Golang and fasthttp. It is designed for low-latency, high-throughput workloads with WebSocket communication support.

Features

• Sharded Cache: Uses multiple shards to improve concurrency.
• Fast HTTP API: Powered by fasthttp for ultra-low latency.
• Optimized Kernel & Docker Settings: Tuned for high traffic and maximum efficiency.
• Efficient Memory Management: Uses a hash-based approach with controlled eviction.

Installation & Setup

Building & Running the Docker Image

docker build -t key-value-cache .
docker run -p 7171:7171 --ulimit nofile=1048576:1048576 --network=host key-value-cache

Optimized Kernel Parameters

To handle high connection loads efficiently, apply these system-level optimizations:

sudo sysctl -w net.core.somaxconn=131072
sudo sysctl -w net.core.netdev_max_backlog=500000
sudo sysctl -w net.ipv4.tcp_tw_reuse=1
sudo sysctl -w net.ipv4.tcp_tw_recycle=1
sudo sysctl -w net.ipv4.tcp_fin_timeout=10
sudo sysctl -w net.ipv4.tcp_max_syn_backlog=262144
sudo sysctl -w net.ipv4.tcp_syncookies=0
sudo sysctl -w net.ipv4.tcp_mem="786432 1048576 1572864"
sudo sysctl -w net.ipv4.tcp_rmem="4096 87380 6291456"
sudo sysctl -w net.ipv4.tcp_wmem="4096 87380 6291456"
sudo sysctl -w net.ipv4.ip_local_port_range="1024 65535"
sudo sysctl -w net.ipv4.tcp_fastopen=3
sudo sysctl -w fs.file-max=2097152
sudo sysctl -w net.ipv4.tcp_keepalive_time=60
sudo sysctl -w net.ipv4.tcp_keepalive_intvl=10
sudo sysctl -w net.ipv4.tcp_keepalive_probes=5

Design Choices & Optimizations

1. Sharded Cache Design

• Uses consistent hashing (djb2) to distribute keys across shards.
• Reduces contention by locking only at the shard level.

2. Kernel-Level Optimizations

• Increased backlog & connection queue: Prevents dropped requests under heavy traffic.
• TCP optimizations: Reduces TIME_WAIT sockets, improves port reuse, and speeds up connections.
• Memory tuning: Optimized TCP buffers for large-scale traffic.

3. Docker Optimizations

• --ulimit nofile=1048576:1048576: Avoids hitting file descriptor limits.
• Host networking (--network=host): Reduces network overhead.

API Endpoints

PUT /put

Stores a key-value pair.

curl -X POST "http://localhost:7171/put" -H "Content-Type: application/json" -d '{"key":"name", "value":"KeyValueCache"}'

GET /get?key={key}

Retrieves a value by key.

curl -X GET "http://localhost:7171/get?key=name"