Eclipse Amlen vs Faye

Eclipse Amlen is a self-hosted MQTT server for IoT and web messaging. It supports MQTT versions 3 through 5 over TCP/IP and WebSockets, plus JMS, and can convert messages between MQTT and JMS. A protocol plug-in SDK lets users add other protocols, including options for legacy sensors that cannot use MQTT. The Amlen Bridge forwards MQTT messages to another MQTT server or IBM Event Streams for IBM Cloud, with filtering, topic mapping, multiple forwarders, and REST API configuration and monitoring. Security controls include TLS profiles, user ID and password authentication against a configured LDAP server, and policy-based authorization for connections, topics, subscriptions, and queues. Administrators can manage message hubs and endpoints through a WebUI or REST Administration APIs. Supported client platforms include C, Java, Android, iOS, and JavaScript. Server and WebUI downloads are listed for RHEL and AlmaLinux 8, 9, and 10. The free software has configurable delivery guarantees. One limitation is that Amlen supports a single LDAP server connection, so users and groups must be provided through that server.

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.