Buoyant

Buoyant's goal is to make it easier to build distributed systems that fit your needs.

Servers in distributed systems need to agree with each other on their state. Buoyant implements the Raft Consensus Algorithm, a relatively understandable algorithm for ensuring all servers agree on their state. This allows you to build a reliable, distributed system that fits your needs. You get to decide how state is stored and how servers communicate with each other. Eventually plugins will be available to make this even easier.

Raft overview

Servers form a cluster. There is a single leader that is allowed to modify its state. The other servers are followers and will replicate the leader's state. If the leader crashes the followers automatically elect a new leader without losing any data. A cluster of three servers can survive the loss of one and still function. A cluster of five servers can lose two.

State is modified using deterministic commands that are applied in-order. The leader replicates these commands to (at least half of) its followers before applying them to its own state. Then the followers do the same. This ensures that each server, eventually, has the same state as the leader.

The Raft website has more details.

Is Buoyant production ready?

No. The 1.0 release will be the first production-ready version.

Requirements

Buoyant requires at least Node.js v6.2.2.

Installation

npm install --save buoyant

Roadmap

• Add proper error types for internal errors
• Implement a TCP transport plugin
• Implement a state persistence plugin
• Document the public API, implementation requirements, how to build custom transports
• 1.0 release
• Support client interactions
• Support modifying the cluster
• Support snapshotting & log compaction
• Implement the leadership transfer extension