In my previous blog (Rigorous Enough! MQTT For The Internet Of Things Backbone), I presented the MQ Telemetry Transport (MQTT) protocol, which helps provide the required communication for smart devices. But without a broker repository or destination to support the protocol, MQTT can’t complete its mission.
In this article, I’ll first review one of the open-standard MQTT repositories called Mosquitto, and then cover IBM MessageSight. In future blogs I’ll present additional information on both the security component and additional broker functionality.
Mosquitto is an open-source (BSD-licensed) message broker that implements the MQTT protocol versions 3.1 and 3.1.1. It provides a lightweight server implementation of the MQTT and MQTT-SN protocols, written in C, so it can run on machines that can’t run a JVM.
Mosquitto regularly has an executable in the order of 120kB that consumes around 3MB RAM with 1,000 clients connected. There have been reports of successful tests with 100,000 connected clients at modest message rates.
In addition to accepting connections from MQTT clients, Mosquitto can bridge to other connected MQTT servers, including other Mosquitto instances. It’s thus possible to architect MQTT server networks, and pass MQTT messages from any network location to any other.
A second repository for MQTT is IBM MessageSight, which is built for high performance to offer persistent, transactional messaging. The hardware is 2U form factor. IBM MessageSight includes built-in security to enable integration with external Lightweight Directory Access Protocol (LDAP) security systems. MessageSight also offers Transport Layer Security (TLS), Secure Sockets Layer (SSL), FIPS 140-2, NSA Suite B ciphers and Level 1 secure Crypotgraphic Store securities.
Fine-grained messaging-authorization policies restrict access based on combinations of: user or group, client identifier, protocol, network interface, listening address and/or port, client IP address or range and destination topic and queue name.
The MessageSight repository supports connectivity to WebSphere Message Broker via JMS and/or MQTT nodes. It also integrates with Java environments and with rich HTML5-based web applications. Additionally, MessageSight allows development of interactive mobile-messaging applications with IBM Worklight Studio Developer, which delivers:
- Friendly APIs and libraries
- MQTT clients and libraries for a variety of platforms (C- and Java-based APIs)
- Libraries for Google Android and Apple iOS
- JMS client
- JavaScript API for HTML5-based applications
- PhoneGap MQTT plugins with JavaScript API for use with IBM Worklight
- Apache Cordova
- Adobe PhoneGap
MessageSight also offers simple and scalable management through policies. A single user ID is defined on the queue manager for IBM MessageSight, which enables a business to sense and respond to data coming from the edge of the enterprise. IBM MessageSight offers high availability with either an active or passive standby.
There are several public repositories that include Hive MQ, which provides a repository that anyone can engage with. In addition, there is cloudMQTT, which is a repository hosted in the cloud. There are other implementations of the broker space, namely gnatMQ, which is an implementation of MQTT but specifically for.Net, and ActiveMQ, which is a product of the Apache group.
