NodeNsync — Distributed Key-Value Store

NodeNsync is a high-performance, distributed key-value store designed for scalability and fault tolerance. It supports clustering, replication, pub/sub messaging, and snapshot-based persistence, making it ideal for applications requiring fast data access with resilience.

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Features

• Distributed Clustering: Automatic leader election and slot-based sharding.
• Replication: Async data synchronization across nodes.
• Persistence: Periodic snapshots to disk for recovery.
• Pub/Sub Messaging: Real-time message broadcasting.
• Role-Based Access: Admin/user roles with session tokens.
• RESP Protocol Support: Compatible with standard Redis CLI tools.
• Rate Limiting: Protect against abusive clients.
• Health Monitoring: Track connections, latency, and memory usage.
• TLS Support: Secure client-server communication.

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Installation

Prerequisites

• Go 1.21+
• Redis CLI (for testing commands)

Steps

1. Clone the repository:

   git clone https://github.com/yourusername/nodensync.git
   cd nodensync

2. Build the binary:

   go build -o nodensync cmd/server/main.go

3. Start the server (default: :6379):

   ./nodensync --listenAddr :6379

Configuration

Flag	Description	Default
--listenAddr	Address to listen on	:6379
--dataDir	Directory for snapshots	./data
--snapshotInterval	Auto-snapshot interval	1m
--rateLimit	Max commands/sec per client	3
--enableTLS	Enable TLS encryption	false

Example:

./nodensync --listenAddr :6380 --dataDir /mnt/data --rateLimit 10 --enableTLS

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Command Reference

Core Commands

Command	Syntax	Description
AUTH	AUTH <username> <password>	Authenticate with role-based access
SET	SET <key> <value>	Store a key-value pair
GET	GET <key>	Retrieve value by key
DEL	DEL <key>	Delete a key
INCR	INCR <key>	Atomically increment integer value

Hash Commands

Command	Syntax	Description
HSET	HSET <key> <field> <value>	Set hash field value
HGET	HGET <key> <field>	Get hash field value

Pub/Sub Commands

Command	Syntax	Description
PUBLISH	PUBLISH <channel> <message>	Broadcast message to channel
SUBSCRIBE	SUBSCRIBE <channel>	Receive messages from channel
UNSUBSCRIBE	UNSUBSCRIBE [channel...]	Stop listening to channels

Administration

Command	Syntax	Description
INFO	INFO	Get server statistics & metrics
ROLE	ROLE	Show node role (leader/follower)
REPLICAOF	REPLICAOF <host> <port>	Configure replication
MONITOR	MONITOR	Stream all executed commands

Utility

Command	Syntax	Description
PING	PING	Check server responsiveness
HELP	HELP	List available commands

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Advanced Features

Clustering Example

Start 3-node cluster:

# Node 1 (Leader)
./nodensync --listenAddr :7000

# Node 2
./nodensync --listenAddr :7001

# Node 3
./nodensync --listenAddr :7002

Join cluster via Redis CLI:

REPLICAOF 127.0.0.1 7000

Replication Setup

Configure node as replica:

127.0.0.1:6380> REPLICAOF 127.0.0.1 6379

Persistence Management

Manual snapshot creation:

SAVE

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Monitoring & Metrics

INFO Output Example

127.0.0.1:6379> INFO
# Server
version:1.0.0
uptime:2h35m
connected_clients:8
used_memory:256MB

# Replication
role:master
connected_slaves:2
master_repl_offset:89234

# Keyspace
db0:keys=1532

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Security

TLS Configuration

1. Generate certificates:

   openssl req -x509 -newkey rsa:4096 -nodes -keyout key.pem -out cert.pem -days 365

2. Start server with TLS:

   ./nodensync --enableTLS --tlsCert cert.pem --tlsKey key.pem

3. Connect with Redis CLI:

   redis-cli --tls --cert ./cert.pem --key ./key.pem -p 6379

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Building from Source

1. Install dependencies:

   go get github.com/tidwall/resp

2. Run tests:

   go test ./...

3. Build with optimizations:

   go build -ldflags "-s -w" -o nodensync cmd/server/main.go

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Contributing

1. Fork the repository
2. Create feature branch: git checkout -b feat/new-feature
3. Commit changes: git commit -am 'Add awesome feature'
4. Push: git push origin feat/new-feature
5. Submit pull request

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FAQ

Q: How is this different from Redis?
A: NodeNsync focuses on horizontal scaling and simplicity, while maintaining Redis protocol compatibility.

Q: Can I use existing Redis clients?
A: Yes! Any RESP-compatible client (redis-py, Jedis, etc.) will work.

Q: Where are snapshots stored?
A: In the dataDir specified at startup (default: ./data).

Q: How to reset the database?
A: Stop server and delete all .json files in the data directory.