Self-host HiveMQ Community Edition

HiveMQ Community Edition (CE) is a Java-based MQTT broker released under the Apache 2.0 license that covers the full MQTT 3.x and 5.0 specification and serves as the open-source core of the commercial HiveMQ platform. Clients connect over plain TCP, TLS, WebSocket or Secure WebSocket, and behaviour such as retained messages, sessions, queues, subscriptions and persistence mode is tuned in a single XML file (conf/config.xml) that the broker reads at startup, with ${ENVVAR} placeholders filled from the environment. Custom authentication, authorization, client initializers and packet interceptors can be written against the Java Extension SDK, and the broker can also be started inside a Java application through its embedded API. Run it by unzipping the official binary package and calling bin/run.sh, with the hivemq/hivemq-ce Docker image, or by building your own package and image from source. Production deployments are supported on Linux only and need OpenJDK 11 or newer, roughly 4 GB RAM, 4 CPUs and 10 GB of free disk.