Go Cache Server

A simple TCP server in Go for managing a key-value cache. This project includes:

• A TCP server that allows clients to interact with the cache over a telnet connection.
• A cache with configurable capacity, TTL, and snapshot persistence using .gob.
• Graceful shutdown for managing connections and ensuring data integrity.

Features

• Key-Value Cache: Supports GET, SET, and DELETE commands.
• Persistence: Cache is saved to disk as a snapshot using Go's gob encoding.
• Eviction: Items automatically expire based on TTL and are periodically evicted.
• Graceful Shutdown: Handles termination signals to close connections and save the cache.
• Thread Safety: Uses mutex locks to ensure safe concurrent access to the cache.

Installation

Prerequisites

• Go 1.16 or higher

Setup

1. Clone the repository:

   git clone https://github.com/Ndeta100/mcache.git
   go get go get github.com/Ndeta100/[email protected]  # or v1.1.0
   cd mcache

2. Install dependencies:

   go mod tidy

3. Build the server:

   go build -o cache-server

Usage

Starting the Server

Run the server executable:

./mcache

By default, the server listens on localhost:6379. You can modify the configuration (config/config.yaml) to change the listening address and port.

Connecting to the Server

You can use a telnet client to connect to the server:

telnet localhost 6379

Commands

• SET: Set a key-value pair in the cache.

  SET key value
  OK

• GET: Retrieve a value by key.

  GET key
  VALUE: value

• DELETE: Delete a key from the cache.

  DELETE key
  OK

• Graceful Shutdown: Press CTRL+C to stop the server. All active connections will be closed, and the cache state will be saved to disk.

Configuration

The server configuration is defined in config/config.yaml. You can set options like:

• host: The server's hostname or IP.
• port: The server's port number.
• capacity: The maximum number of items allowed in the cache.
• ttl: The time-to-live for cache entries, in seconds.

Graceful Shutdown

The server supports graceful shutdown, allowing it to:

• Stop accepting new connections.
• Close all active connections.
• Save the current cache state to disk.

This is triggered when the server receives a termination signal (SIGINT or SIGTERM).

Development

Running Tests

You can run unit tests for the cache and server:

go test ./...

Code Structure

• server: Contains the TCP server code.
• store: Implements the key-value cache with persistence and TTL.
• handler: Handles client commands (GET, SET, DELETE).
• config: Contains configuration utilities.

Improvements to Consider

• Logging: Improve logging for better observability of server events.
• Authentication: Add authentication to limit access to the cache.
• REST API: Implement a RESTful API for more accessible programmatic interaction.
• Optimized Persistence: Implement incremental snapshots or append-only logs for more efficient persistence.

Contributing

Pull requests are welcome! For major changes, please open an issue first to discuss what you would like to change.

License

This project is licensed under the MIT License. See the LICENSE file for details.