MQTT Broker: OFFLINE - COMMUNICATION_ERROR Timeout

Add-ons Bindings
1

Hi everybody,
I am a unix and linux enthusiast for 20 or more years and have a lot of experience in debugging things. But here I come to my limits.

I am using latest stable openhab 2. (How can I find out what is the exact version?)

I installed MQTT Binding like in this video: https://www.youtube.com/embed/5IrIg9eQcX0?autoplay=1&feature=oembed&wmode=opaque

This means when using PaperUI

  • Addons->Bindings->MQTT Binding
  • Configuration->Things-> ADD
  • MQTT Binding -> Add Manually
  • MQTT Broker (I have a mosquitto running on the same server)
  • so configured for localhost
  • Saved
    Thing is now showing : Status: OFFLINE - COMMUNICATION_ERROR Timeout

So what did I do wrong? Why do no log entries show up in openhab.log?
I even set logging for org.openhab to DEBUG

How do I get the error messages, that explain, what is wrong? Where are the log entries?

Thanks for your support!
samba

2

The karaf console shows the build when you log in.

3

if you ssh to your openhab, the version is right below the big openhab logo
or openhab-cli info

(latest stable is 2.4.0)

i installed the mqtt embedded broker today and it stayed offline too.
an OH restart helped. maybe clear cache too.

openhab-cli stop
openhab-cli clean-cache
openhab-cli start
4

Thanks for that.
Yes version is 2.4.0

5

Thanks so much. That helped.

Still it would be great to know, why I did not see anything in the logs. What do I need to do to activate enough logging?
I already used karaf console to activate DEBUG level, but there was nothing in the logs.

6

is your setup working now ?
can’t help you with logging, have the same “problem” i don’t see anything regarding mqtt as well.

i tested my mqtt settings with mqtt.fx and was able to connect, subscribe and publish. all looked good. and my mqtt OH setup works now with 2.4 binding. yeeeeha

7

So after stopping openhab and running
openhab-cli clean-cache
and then restarting openhab it works now.

1 Like
8

My openHAB was working since last one month but yesterday suddenly showed this error “MQTT broker: OFFLINE-COMMUNICATION ERROR” and even mqtt.fx is not connected. I cleared the Cache and tmp file (inside). Please help me what can I do?