ratchetphp/Ratchet
Ratchet
Ratchet is a PHP library for building asynchronous WebSocket servers that handle persistent, bidirectional communication between clients and the server. It provides a complete server-side WebSocket implementation, including protocol handshake negotiation, message framing over TCP, and an event-loop-based concurrency model that manages thousands of simultaneous connections without blocking.
The library implements a connection registry pattern for tracking all active WebSocket sessions, enabling the server to broadcast or unicast messages to any connected client on demand. It relies on non-blocking I/O through libevent or stream_select, and supports installing kernel-level evented I/O handlers for maximum concurrency. For production deployment, Ratchet runs on a separate TCP port or subdomain from the main HTTP server and integrates with process supervisors like Supervisor to automatically restart the application after unexpected failures.
The project covers the full lifecycle of WebSocket server operation, from connection management and bidirectional messaging to system-level tuning for raising open connection limits. Its documentation addresses deployment alongside traditional web servers, reverse proxy integration, and the operational considerations for running persistent PHP server processes.
Features
- WebSocket Servers - Combines an I/O server, WebSocket protocol handler, and custom logic to serve WebSocket connections.
- Bidirectional Messaging - Provides persistent two-way messaging over WebSocket connections without request-response pairing.
- PHP - Implements the WebSocket protocol in PHP for building real-time messaging and event-driven server applications.
- Websocket Connection Managers - Tracks every open WebSocket connection in a single server process for on-demand client communication.
- Real-time Communication Servers - Provides a server-side PHP solution for maintaining persistent connections and exchanging messages in real-time.
- Asynchronous PHP Servers - Provides a non-blocking PHP server framework using ReactPHP's event loop for concurrent WebSocket connections.
- WebSocket Frame Processors - Encodes and decodes WebSocket frames with masking, opcode handling, and fragmentation for reliable data transfer.
- WebSocket Protocol Upgrades - Upgrades HTTP requests to persistent WebSocket connections by parsing Upgrade headers and Sec-WebSocket-Key.
- WebSocket Connection Registries - Maintains a central map of active WebSocket connections for broadcasting or unicasting messages.
- Non-Blocking Socket I/O - Uses libevent or stream_select to handle socket reads and writes asynchronously without blocking.
- Non-Blocking Event Loops - Manages thousands of simultaneous connections using a single-threaded event loop that polls for I/O readiness.
- Event and Async Programming - Builds real-time web socket applications.
