Track end-to-end latency to your MQTT broker

Tracking end-to-end latency (response time) is useful in selecting your
MQTT broker, as well as monitoring your IoT platform / broker performance.

Check this real-time latency dashboard at

http://latency.iotsim.io/

which tracks end-to-end response time every second to a number of
public MQTT brokers over the internet. The local intranet mosquitto broker
measurement is for comparison.

The NODE-RED source code is at

https://github.com/gambitcomminc/nodered-mqtt-latency