ExRingRing

A consistent hash ring implementation in Elixir with Clean Architecture.

⚠️ EXPERIMENTAL / UNDER ACTIVE DEVELOPMENT ⚠️

It is currently in early development and NOT READY FOR PRODUCTION USE.

Features

• Consistent hashing for distributed systems
• Virtual nodes for balanced key distribution
• Node weights for weighted distribution
• Phantom nodes (weight 0) for standby members
• Multiple hash algorithms: MD5, SHA, SHA256, CRC32, phash2
• Two implementation strategies: Static (fast reads) and Dynamic (fast writes)
• Minimal redistribution when nodes join or leave

Installation

def deps do
  [
    {:ex_ring_ring, "~> 0.1.0"}
  ]
end

Quick Start

# Create nodes and a ring
nodes = ExRingRing.list_to_nodes([:a, :b, :c, :d, :e])
ring = ExRingRing.make(nodes)

# Find which node owns an item
{:ok, node} = ExRingRing.find_node(ring, "my_key")
node.key  # => :a (deterministic)

# Collect N nodes for replication
nodes = ExRingRing.collect_nodes(ring, "my_key", 3)

# Add and remove nodes at runtime
ring = ExRingRing.add_node(ring, ExRingRing.Domain.Entities.Node.make(:f))
ring = ExRingRing.remove_node(ring, :c)

Guides

• Getting Started — Installation, basic usage, examples
• Architecture — Clean Architecture layers, module design
• Configuration — Hash algorithms, virtual nodes, weights
• Implementation Strategies — Static vs Dynamic trade-offs

License

Apache License 2.0