🚀 Tejas-DB: High-Performance Distributed Key-Value Store

A highly concurrent, fault-tolerant, and masterless distributed Key-Value store built entirely from scratch in Modern C++, featuring a real-time visual dashboard built in React & Tailwind CSS.

Engineered to handle massive scalability, this system implements core distributed systems concepts inspired by Amazon Dynamo and Apache Cassandra.

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✨ Core Architecture & Features

1. 🔄 Consistent Hashing & Data Distribution

• Implemented a Ring Topology using the 64-bit FNV-1a Hash Algorithm to ensure uniform data distribution and eliminate hot spots.
• Configured with 100 Virtual Nodes (vNodes) per physical server to achieve perfect load balancing and seamless scaling.

2. 🛡️ Fault Tolerance & Replication

• Strict Quorum Logic (W=2): Ensures strong consistency. A write operation is only considered successful if acknowledged by at least 2 nodes. Fails safely with automatic rollback.
• Write-Ahead Logging (WAL): Disk-backed crash recovery. Every node recovers its exact state from local logs instantly upon reboot.
• Gossip Protocol: Background heartbeat threads monitor cluster health, instantly detecting node failures and dynamically updating the routing topology.

3. ⚡ High-Performance Concurrency

• Architected a thread-safe custom Storage Engine utilizing std::shared_mutex (Read-Write Locks).
• Achieved 16,132 Requests Per Second (RPS) with a highly concurrent load of 100 simultaneous threads, maintaining an average latency of just ~6ms (Benchmarked via Apache ab).

4. ⚖️ Elastic Scaling & Live Rebalancing

• Dynamically supports adding or removing nodes.
• Exposes an /admin/rebalance endpoint that intelligently calculates hash boundaries and migrates live data to new nodes without cluster downtime.

5. 🖥️ Interactive Visual Dashboard (Control Center)

• A real-time React/Vite dashboard that visualizes the Consistent Hashing Ring.
• Chaos Engineering Controls: Inject massive workloads or simulate node deaths with a single click to visually demonstrate data rebalancing and fault tolerance in real-time.

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🛠️ Tech Stack

• Backend Engine: Modern C++ (C++17)
• Networking/HTTP: cpp-httplib
• Frontend UI: React.js, Vite, Tailwind CSS
• Performance Testing: Apache Bench (ab) & Custom Bash Scripts

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🚀 Getting Started

Prerequisites

• GCC/G++ (Supports C++17)
• CMake & Make
• Node.js & npm (For the UI)

1. Build the Backend

mkdir build && cd build
cmake ..
make