foxtail

Foxtail is a distributed KV database

Disclaimer

This project is not meant to be used in production. Please be aware of that! This project aims to sharpen my Go and distributed systems skills.

Plan

The original idea is to take an incremental approach while developing this database, and the first high-level plan is as follows:

1. Implement a basic set of functions for an in-memory KV database
2. Expose the KV functionality over a high-level API (gRPC, HTTP, etc)
3. Implement a client for the public API
4. Make things more interesting, by throwing Raft on top of the existing codebase
5. Write down an extensive set of acceptance tests for the new distributed KV setup
6. Find out a way to implement durable storage, but still offer the in-memory option

Mode details

This section will be updated as I make progress in the areas listed above. The goal is to build a complex system but in an incremental fashion. I expect to discover more requirements on the way, so this means the design of the DB can change quite frequently.

In-memory KV database

To keep things simple at the beginning, Foxtail will only provide a set of functions:

PUT(key, value) where key is a string and value is a binary. It saves the new value into the given key. If the value does not previously exist, it will create a new entry on the database, otherwise, the existent one will be overwritten.

GET(key) where key is a string. It will return the binary associated with that given key, and in case the key does not exist, returns nil.

DELETE(key) where key is a string. It will delete an existing key and its associated value. If the key does not exist, it returns nil.

The actual constraints for the key and value, such as max length, allowed characters and etc, are yet to be defined.