Faye vs RabbitMQ

Faye is a publish-subscribe messaging system that uses the Bayeux protocol. It provides message servers for Node.js and Ruby, plus clients for servers and major web browsers. Browser clients rely on a Faye server to relay messages; they can retry after a lost connection and redeliver dropped messages. Transport adapters cover WebSocket, HTTP long-polling, Cross Origin Resource Sharing, and JSON-P callback-polling. Server and client extensions can intercept or modify messages, including to add subscription authentication. The monitoring API reports handshakes, subscriptions, unsubscriptions, publishes, and disconnections. Faye runs on Linux, macOS, and Windows, and can be self-hosted. Its default in-process engine cannot span multiple front-end web servers, but Redis and Couchbase engines are documented for distributed deployments. Faye is free and open source under the Apache 2.0 license; the listed plan is free. Install the Node.js server through npm or the Ruby server through RubyGems.

RabbitMQ is an open source messaging and streaming broker for application communication, including distributed microservices, real-time data, and IoT. Publishers can route messages to one or more consumers using routing, filtering, streaming, and federation. Message acknowledgements and replication across a cluster support delivery reliability, and delivery guarantees are configurable. Supported protocols include AMQP 0-9-1, AMQP 1.0, MQTT, STOMP, RabbitMQ Streams, HTTP, and WebSocket, including browser communication over WebSocket. Client libraries are available for Java, .NET/C#, Erlang, and other languages; the project also offers a community Docker image and Kubernetes operators. RabbitMQ can run in cloud or on-premises environments, on local machines and physical or virtual hardware, and in containers. Linux, Windows, and macOS are supported; z/OS, most mainframes, and systems with less than 100 MB of RAM are not. The free, self-managed Open Source RabbitMQ Server is offered under the Mozilla Public License 2.0 with best-effort community support. VMware Tanzu RabbitMQ is a commercial offering with 24/7 support and enterprise features; pricing is by contact.