Autoscanning Logback configuration

A reason for breaking the decoupling between SLF4J and the underlying concrete logging framework is for changing the current log configuration without having to restart the application.

Logback has a feature that could be used to get a similar result leaving all the configuration stuff in a file. The idea is specifying in the configuration if Logback has to check again the configuration file and, if a change is detected, reload the properities.

This is achieved adding a couple of attributes to the configuration element for XML files (scan="true" scanPeriod="30 seconds" in my case, where I wanted to rescan the file each half minute - default value for scanPeriod is one minute).
For Groovy configuration we just have to add A call to scan("30 seconds").

I had a bumpy beginning of a relation with this feature, I couldn't make it work. But this was a good way to keep in touch with the internal Logback debug setting to get information on what was going.

Here is the XML configuration file that I used to test the autoscanning feature:
<configuration scan="true" scanPeriod="30 seconds" debug="true">
  <statusListener class="ch.qos.logback.core.status.OnConsoleStatusListener" />
  <appender name="capp" class="ch.qos.logback.core.ConsoleAppender"> 
    <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder"> 
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{40}: %msg%n</pattern> 
  <root level="all"> 
    <appender-ref ref="capp" /> 
The configuration element has three attributes, the first two ones for scanning and the third, named "debug", set to true, to let Logback giving debug feedback. I couldn't find how I could do the same in a Groovy configuration file (if someone knows, please, drop a comment).
Then I added a statusListener element specifying as associated class the one to send output to the standard console, and that was it.

No comments:

Post a Comment