MQTT Broker - Mosquitto Event Logging

Question

Is it possible to use the MQTT Broker Mosquitto on Ubuntu 12.04 to log all events such as messages published to all channels, subscriptions, client connections/disconnections and errors to a log file with a time stamp and then have program insert this into a database either Mongodb or SQL?

If so, how could this be achieved?

Answer 1

Yes you can do this.

You can add timestamp data to the Mosquitto output by doing the below for example:

mosquitto_sub -v -t '#' | xargs -d$'\\n' -L1 sh -c 'date "+%D %T $0"'

You could obviously output this to a text file as well via doing the following:

mosquitto_sub -v -t '#' | xargs -d$'\\n' -L1 sh -c 'date "+%D %T $0"' > /var/tmp/My_Mosquitto.log

You can view the log file via:

cat /var/tmp/My_Mosquitto.log

You would then have to write say a php script that reads this text file and adds the data to a database table.

Another ( much better ) option would be to use node.js to log all the MQTT data to a mysql database table. There are examples of how to do this all over the internet - this is how I do it.

Answer 2

AFAIK this isn't possible right now with mosquitto. For use cases like this I would recommend to use a MQTT broker which has a plugin and message interception system like HiveMQ . To see all the interactions, there are some plugins available as open source like the Message Log Plugin . The source code is also available on Github .

To write eg the messages to a database, look at this blog post , this should help you get started.

Note that I may be biased because I work on HiveMQ.