{scrollbar}

4.3. Logging system

Karaf provides a powerful logging system based on OPS4j Pax Logging.

In addition to being a standard OSGi Log service, it supports the following APIs:

• Apache Commons Logging
• SLF4J
• Apache Log4j
• Java Util Logging

Karaf also comes with a set of console commands that can be used to display, view and change the log levels.

Configuration

The configuration of the logging system uses a standard Log4j configuration file at the following location:

[karaf]/etc/org.ops4j.pax.logging.cfg

You can edit this file at runtime and any change will be reloaded and be effective immediately.

Commands

The log subshell comes with 3 commands:

• log:display: display the last log entries
• log:display-exception: display the last exception from the log
• log:get: show the log levels
• log:set: set the log levels

For example, if you want to debug something, you might want to run the following commands:

> log:set DEBUG
... do something ...
> log:display

Note that the log levels set using the log:set commands are not persistent and will be lost upon restart.
To configure those in a persistent way, you should edit the configuration file mentioned above.
#top

{scrollbar}