MQTT 以及 mosquitto

MQTT^[1] (MQ Telemetry Transport or Message Queuing Telemetry Transport) is an ISO standard (ISO/IEC PRF 20922)^[2] publish-subscribe-based "lightweight" messaging protocol for use on top of the TCP/IP protocol. It is designed for connections with remote locations where a "small code footprint" is required or the network bandwidth is limited. 

mosquitto is an MQTT v3.1 broker.

Usage: mosquitto [-c config_file] [-d] [-h] [-p port]

 -c : specify the broker config file.

 -d : put the broker into the background after starting.

 -h : display this help.

 -p : start the broker listening on the specified port.

      Not recommended in conjunction with the -c option.

 -v : verbose mode - enable all logging types. This overrides

      any logging options given in the config file.

See http://mosquitto.org/ for more information.

How to test mosquitto ?

use different terminal:

• Run mosquitto

ex. mosquitto -p 192.168.157.75:1883

1479797828: mosquitto version 1.4.1 (build date 2016-02-25 01:02:01-0800) starting

1479797828: Using default config.

1479797828: Opening ipv4 listen socket on port 192.

1479797828: Opening ipv6 listen socket on port 192.

mosquitto_sub - mosquitto subscription client

• Start the command line subscriber

mosquitto_sub -v -t 'test/topic' 

• Publish test message with the command line publisher:

mosquitto_pub -t 'test/topic' -m 'helloWorld'