Short description

JMX bean which provides the functionality to change the log level of a class/package and to reload the log4j.properties during runtime.

Introduction

I was facing the problem to change log4j.properties settings of classes/categories during runtime of an application. Additionally i wanted to have also the possibility to reset/reload the settings again like they was before. After studying log4j documentation i couldn't find only a half solution materialized as an jmx bean (http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/jmx/package-summary.html). After deeper google search for this issue, i found several hints how to solve this issue, which i would like to combine here.

Details

Requirements

Java SUN JDK 1.5 - http://java.sun.com/javase/downloads/index_jdk5.jsp
Apache log4j >= 1.2.15 - http://logging.apache.org/log4j/
Maven2 2.0.x - http://maven.apache.org/
Spring >= 2.5 - http://www.springsource.org/

Functionality

All functionalities are grouped in the interface http://code.google.com/p/logging-jmx-service/source/browse/trunk/logjmxservice/src/main/java/de/stefanheintz/log/jmxservice/LoggingConfig.java of the JMX MBean http://code.google.com/p/logging-jmx-service/source/browse/trunk/logjmxservice/src/main/java/de/stefanheintz/log/jmxservice/LoggingConfigImpl.java:

setting of TRACE, DEBUG, INFO, WARN, ERROR, FATAL log levels for a class or category
disabling of logging of a class or category
show runtime log4j settings
reload the log4j.properties settings from classpath

Short demonstration:

More details are available at the Tutorial page.

Version history

Version	Date	Descritpion
1.1.1	2009-05-10	Small NPE bug fixing for changing log level of a class having no log level yet
1.1.0	2009-02-10	Sending notifications whenever a log level change or reloading was triggered
1.0.0	2009-01-04	First implementation including setting of log levels and reloading of the log4j.properties

References

Monitoring and Management Using JMX:

See page http://java.sun.com/j2se/1.5.0/docs/guide/management/agent.html
Article about jconsole http://java.sun.com/developer/technicalArticles/J2SE/jconsole.html

JMX bean export

An easy way to expose jmx beans is with spring. See details at http://static.springframework.org/spring/docs/2.0.x/reference/jmx.html

Reload of log4j properties:

See very helpful hint at page http://www.bright-green.com/blog/2003_10_28/how_to_re_read_log4jproperties.html