MOSQUITTO-1-3-5-RELEASE-NOTES.PDF

This document describes the VMS Software port of the Mosquitto MQTT broker (version 1.3.5) for OpenVMS I64, released in October 2015.

Mosquitto is an open-source, BSD-licensed message broker that implements MQTT versions 3.1 and 3.1.1. It's a lightweight publish-subscribe messaging protocol designed for remote connections, low-bandwidth environments, and mobile applications. The OpenVMS port includes all standard Mosquitto features such as SSL/TLS support, bridging, client authentication, and access controls.

A notable feature in this release is an OpenVMS-specific plugin that allows the Mosquitto broker to authenticate users by checking their credentials against the system's SYSUAF database. However, this plugin currently only handles authentication and not authorization after a user connects.

Installation is carried out using an OpenVMS PCSI kit via the PRODUCT INSTALL command. Post-installation steps include configuring the broker to start and stop automatically with OpenVMS, verifying its operation, checking log files, and running test programs. System requirements include OpenVMS 8.4 I64, HP TCP/IP Services V5.7, HP C V7.3-018, and OpenSSL 1.0.1j, with installation on an ODS-5 enabled file system recommended. Specific OpenVMS privileges and system quotas are required for the broker to function efficiently.

Configuration of the broker and the SYSUAF authentication plugin is done by editing the MOSQUITTO.CONF file. A known issue highlighted is the broker's potential to attempt binding to IPv6 addresses even when not enabled, causing startup failures, which can be resolved by explicitly setting the bind_address parameter to an IPv4 address. The document notes that this release uses an older Mosquitto version (1.3.5) and that VMS Software Inc. plans to release newer versions with expanded OpenVMS-specific functionality in the future.