On migrating to OH3, I’m getting messages like the one below.
How do I find out which module they originate from? The name is cut off 
Is there any general setting in .cfg or Karaf that makes me see full length module names in here ?
2020-12-07 13:10:07.575 [INFO ] [.reconnect.PeriodicReconnectStrategy] - Try to restore connection to '192.168.178.40'. Next attempt in 10000ms
Searching for that string it looks like OH2 behaves in the the same way.
First characters of logging messages always miss.
The message seems ( my guess ) to belong to the MQTT binding as most if not all postings that contain this string in logging are related to MQTT.
I’ve never read about that this is configurable for OH2 so I doubt that there is any possibility for OH3.
Yes it has been like that ever (I didn’t say it’s new behavior in OH3).
But it has been annoying ever …
I made a search in the openhab-addons repo on github, seems like it’s in the mqtt transport bundle:
org.openhab.core.io.transport.mqtt.reconnect.PeriodicReconnectStrategy
Thanks yes it went away when I fixed an issue with mosquitto config.
But it’s rather about the generic answer: how to get to see the full string in logs ?
I’m not sure, but I think you’d have to edit the
log4j2.appender.audit.layout.pattern = %d{yyyy-MM-dd HH:mm:ss.SSS} [%-5.5p] [%-36.36c] - %m%n
in /var/lib/openhab2/etc/org.ops4j.pax.logging.cfg
The [%-36.36c] should be the relevant field, try increasing the numbers and see if it helps.
Get rid of the precision and change it (the field Anders pointed out) to [%c] and it will print the fully qualified category without truncating it. More details at https://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/PatternLayout.html.