OSMC 2014: MQTT for monitoring (and for the lo t) | Jan-Piet Mens
description
Transcript of OSMC 2014: MQTT for monitoring (and for the lo t) | Jan-Piet Mens
MQTT for monitoring (and for the IoT)
Jan-Piet MensNovember 2014
@jpmens
MQTT is a standard, a transport,
PUB/SUB messaging, designed for
unreliable networks
transport protocol
binary payload, 256MB, (+2 bytes), fast,
lightweight, ideal for low-bandwith, high-latency networks
security
TLSauthentication
ACLsTLS-PSK
(payload encryption)
Quality of Service
0 At most once
1 Assured delivery
2 Once only
more featureskeepalive
last will & testament,decoupled senders/recipients,
durable messages
topic names
UTF-8, hierarchical, wildcards
temperature/room/livingdevices/#finance/+/eur/rate
PUB/SUB cauldron
MQTT brokersthe server bit of MQTT
Mosquitto C, fast, lightweight, ACLs (plugin), TLS, TLS-PSK, bridge,
Websockets, logging via $SYS
http://mosquitto.org
HiveMQ Java, plugins, Websockets, clustering, modules
http://hivemq.com
MQTT brokers$SYS topic
$SYS/broker/clients/total 1771$SYS/broker/messages/received 36597465$SYS/broker/messages/sent 39714120$SYS/broker/messages/stored 2941$SYS/broker/bytes/received 2830787008$SYS/broker/bytes/sent 3810653433$SYS/broker/version mosquitto version 1.4$SYS/broker/publish/messages/received 19798673$SYS/broker/publish/messages/sent 30622855$SYS/broker/publish/bytes/received 1868229299$SYS/broker/publish/bytes/sent 3185942282
bridging
CLI utilitiesmosquitto_sub -v [-h localhost] [-p 1883] [--cafile file] [--cert file --key file] [-u username [-P password]] [ --tls-version tlsv1.2 ] -t 'topic/#'
subscribe
publish
mosquitto_pub ... [-r] -t topic -m payload
languages
Lua, Python, C, JavaScript, Perl, Ruby, Java, ...
Python API: PUB#!/usr/bin/env python
import paho.mqtt.publish as mqtt
mqtt.single('conf/hello', 'Hello MQTT')
$ mosquitto_sub -h localhost -v -t 'conf/#'conf/hello Hello MQTT
payloadtopic
Python API: SUB
callbacks
#!/usr/bin/env python
import paho.mqtt.client as paho
def on_connect(mosq, userdata, rc): mqttc.subscribe("conf/+", 0)
def on_message(mosq, userdata, msg): print "%s %s %s" % (msg.topic, str(msg.payload), userdata)
data = { 'type' : 'conference' }mqttc = paho.Client(userdata=data)mqttc.on_connect = on_connectmqttc.on_message = on_message
mqttc.connect("localhost", 1883, 60)mqttc.loop_forever()
Python API: SUB
$ mosquitto_pub -t 'conf/thirsty' -m 'Beertime?'$ mosquitto_pub -t 'conf/catering' -m 'Coffee is ready'
$ ./sub.pyconf/thirsty Beertime? {'type': 'conference'}conf/catering Coffee is ready {'type': 'conference'}
practical solutions
alerting, metering, logging, location awareness, tracking, automation, and controlling, host monitoring
alerting: mqttwarn
https://github.com/jpmens/mqttwarn
temperature: Arduino
huh?
all good!
how does this work?
arduino/10.0.69.105/celsius 24
critical: not good!
via MQTT to mobile
mqtt.org @mqttorg