Core Changes: - Completely rewrote CustomResolver reducer with dependency-ordered processing - Enhanced plugin initialization with proper dependency injection - Improved delta processing and property value tracking - Added robust error handling for duplicate property IDs Resolver Improvements: - Updated to use new accumulator structure - Implemented execution order processing for plugins - Enhanced debug logging and error reporting - Simplified TimestampResolver by removing unused initializer Configuration Updates: - Added TypeScript path aliases for test helpers - Improved module resolution paths Key Benefits: - More robust plugin dependency management - More efficient state updates - Enhanced type safety - Better error messages and debugging - More consistent plugin initialization This refactoring focuses on improving the robustness of the resolver, especially around plugin lifecycle management and dependency handling. The changes ensure better separation of concerns and more predictable behavior when dealing with complex plugin dependencies.
7.3 KiB
7.3 KiB
Rhizome on the BEAM: Implementation Guide
Note
: This document outlines a fresh implementation of Rhizome in Elixir, using the TypeScript implementation as a reference.
Table of Contents
- Motivation
- Architecture Overview
- Migration Strategy
- Key Components
- Data Synchronization Model
- Development Roadmap
- Performance Considerations
Motivation
Moving Rhizome to Elixir and the BEAM virtual machine provides several key advantages:
-
Distribution by Default
- Built-in distribution primitives for node-to-node communication
- Network partition tolerance out of the box
- Location transparency for processes
-
Fault Tolerance
- Let it crash philosophy with supervision trees
- Self-healing systems through process isolation
- Hot code reloading for zero-downtime updates
-
Concurrency Model
- Lightweight processes for handling millions of concurrent connections
- Efficient message passing between processes
- Built-in backpressure handling
-
Ecosystem Benefits
- Mature tooling for distributed systems
- Strong pattern matching and immutability
- Excellent support for building resilient systems
Architecture Overview
Current TypeScript Architecture
graph TD
subgraph "TypeScript Implementation"
A[HTTP API<br/><small>Express</small>]
B[WebSocket<br/><small>Socket.IO</small>]
C[Core Engine]
D[Delta Store]
E[View Layer]
F[Persistence<br/><small>LevelDB</small>]
G[Peer Network<br/><small>Libp2p</small>]
A --> C
B --> C
C --> D
C --> E
D --> F
C --> G
end
Proposed Elixir Architecture
graph TD
subgraph "Elixir Implementation"
A[HTTP/WebSocket<br/><small>Phoenix</small>]
B[Core OTP App]
C[Delta Store]
D[View Layer]
E[Process Supervision]
F[Distribution<br/><small>EPMD/GenRPC</small>]
G[Persistence<br/><small>Mnesia/ETS</small>]
A <--> B
B <--> C
B <--> D
B <--> E
B <--> F
C <--> G
end
Implementation Roadmap
1. Core Engine
-
Delta Processing
- Define core Delta types and operations
- Implement DeltaBuilder
- Design storage layer (Mnesia/ETS)
-
View System
- Implement Lossy/Lossless views
- Create resolver framework
- Add caching layer
2. Distribution
-
Node Communication
- Node discovery and membership
- Delta synchronization protocol
- Conflict resolution strategies
-
Plugin System
- Plugin behavior and lifecycle
- Dependency management
- Hot code reloading
3. API & Tooling
-
HTTP/WebSocket API
- RESTful endpoints
- Real-time updates
- Authentication/authorization
-
Developer Experience
- TypeScript type generation
- CLI tools
- Monitoring and metrics
Key Components
1. Delta Processing
This implementation will follow similar patterns to the TypeScript version but leverage Elixir's strengths:
defmodule Rhizome.Delta do
@type t :: %__MODULE__{
id: String.t(),
creator: String.t(),
timestamp: integer(),
operations: [operation()],
transaction_id: String.t() | nil,
negate: boolean()
}
defstruct [:id, :creator, :timestamp, :operations, :transaction_id, negate: false]
def new(creator, host) do
%__MODULE__{
id: generate_id(),
creator: creator,
timestamp: System.system_time(:millisecond),
operations: []
}
end
def add_operation(delta, operation) do
%{delta | operations: [operation | delta.operations]}
end
end
2. View System
defmodule Rhizome.View.Lossy do
@behaviour Rhizome.View.Behaviour
@impl true
def init(initial_state) do
%{state: initial_state, cache: %{}}
end
@impl true
def reduce(%{state: state} = view, delta) do
new_state = apply_delta(state, delta)
%{view | state: new_state}
end
@impl true
def resolve(%{state: state}), do: state
defp apply_delta(state, %Delta{operations: ops}) do
Enum.reduce(ops, state, &apply_operation/2)
end
end
3. Plugin System
defmodule Rhizome.Plugin do
@callback init(args :: term) :: {:ok, state :: term} | {:error, reason :: term}
@callback handle_delta(delta :: Delta.t(), state :: term) :: {:ok, new_state :: term} | {:error, term}
@callback handle_call(request :: term, from :: {pid, reference}, state :: term) ::
{:reply, reply, new_state} |
{:reply, reply, new_state, timeout | :hibernate} |
{:noreply, new_state} |
{:noreply, new_state, timeout | :hibernate} |
{:stop, reason, reply, new_state} |
{:stop, reason, new_state} when reply: term, new_state: term, reason: term
defmacro __using__(_opts) do
quote do
@behaviour Rhizome.Plugin
use GenServer
# Default implementations
@impl true
def init(_args), do: {:ok, %{}}
@impl true
def handle_call(_request, _from, state), do: {:reply, :ok, state}
def start_link(args) do
GenServer.start_link(__MODULE__, args, name: __MODULE__)
end
end
end
end
Data Synchronization Model
1. Delta Propagation
sequenceDiagram
participant C1 as Client 1
participant N1 as Node 1
participant N2 as Node 2
participant N3 as Node 3
C1->>N1: Submit Delta
N1->>N1: Apply Delta Locally
N1->>N2: Gossip Delta
N1->>N3: Gossip Delta
N2->>N2: Apply Delta
N3->>N3: Apply Delta
N2->>N1: Acknowledge
N3->>N1: Acknowledge
2. Conflict Resolution
- Last Write Wins (Default)
- Custom Resolvers
- CRDT-based for special cases
Development Milestones
1. Core Delta Engine
- Define delta types and operations
- Implement DeltaBuilder
- Basic storage with Mnesia/ETS
- View system with Lossy/Lossless support
2. Distributed Foundation
- Node discovery and membership
- Delta synchronization protocol
- Conflict resolution strategies
- Plugin system
3. Production Features
- HTTP/WebSocket API
- Authentication & authorization
- Monitoring and metrics
- Developer tooling
Performance Characteristics
Key Advantages
-
Concurrency
- Handle 100K+ concurrent connections per node
- Sub-millisecond delta processing
- Linear scaling with cores
-
Memory Usage
- Shared binary heap for deltas
- Efficient garbage collection
- Process isolation for fault tolerance
-
Network Efficiency
- Delta compression
- Batched updates
- Smart backpressure handling
Getting Started
Prerequisites
- Elixir 1.14+
- Erlang/OTP 25+
- Node.js (for assets)
Running Locally
# Clone the repository
git clone https://github.com/your-org/rhizome-beam.git
cd rhizome-beam
# Install dependencies
mix deps.get
cd assets && npm install && cd ..
# Start the application
iex -S mix phx.server
Contributing
- Fork the repository
- Create a feature branch
- Submit a pull request
License
[Your License Here]
Acknowledgments
- The Elixir and Erlang communities
- The original TypeScript implementation for inspiration
- Research in distributed systems and CRDTs