Versions Compared

Version Old Version 4 New Version 5
Changes made by

Benjamin Schröder

Armin Franke

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

External link to the Apache Log4J project web page: https://logging.apache.org/log4j/2.x/

 

Log rotation can be configured by Log4J2 appender or on Linux using utilities like logrotate (external link: https://linux.die.net/man/8/logrotate). logrotate utility is not shipped with the tia Core cloud image and therefore not available for cloud deployment.

By default, tia Core implements log rotation using Log4Js RollingFileAppender (see file <webapp>\WEB-INF\classes\log4j2.xml):

·        tia Core writes the log file core-of-tia.log in the logs sub directory of the web application base directory.

·        At 0:00am and in case the log file exceeds 1GB, it is gz-compressed and renamed to core-of-tia-<n>.log.gz.

·        Up to 10 compressed log files will be kept before removal.

 

Use Spring Boot 2 configuration to specify the location of a custom log4j2.xml file and to specify log level for specific components overruling the default settings in the file.

 

Best It is best practice for modifications to Log4J2 configuration is to copy existing log4j2-spring.xml file to a custom version (e.g. my.log4j2.xml) that then is modified and linked in by setting logging.conf parameter (see below).

 

tia Core builds also on top of Spring Boot 2 framework, so that at the start of the system, the configuration is applied via this framework.

External link to the Spring Framework web page: https://spring.io/projects/spring-boot

The required parameters are listed below:

...

The required logging parameters are:

Parameter

Description

Supported Values

Required

Default value

logging.level.<package>

Definition of the log level for the package

OFF; ERROR; WARN; INFO; DEBUG

n

no

logging.config

Specifies a location for the

log4j2.xml to be used instead

configuration file of the

default

logging framework

A path specified absolute or relative to the working directory of tomcat service, e.g. <tomcat installation directory>/bin.

n

no

 

How exactly to specify these parameters depends on the deployment option selected.

Note: kgs recommends to stick with the described best practice configuration described in the subchapters to this topic. It is possible that more advanced configuration may lead to system behavior that is hard to analyze.

...

log4j2.xml

For more information how to apply these parameters, please read Application wide settings .

Log rotation

In production systems, log files can grow large over time and consume disc space as well. Also handling of large log files for issue analysis is getting more difficult. Log rotation refers to an automatic set up to periodically or on trigger event (like log file exceeds a specified size) copy log files aside and keep only a certain number of copies.

Log rotation can be configured by Log4J2 appender.

By default, tia Core implements log rotation using Log4Js RollingFileAppender (see file <webapp>\WEB-INF\classes\log4j2.xml) like this:

  • tia Core writes the log file core-of-tia.log in the logs sub directory of the web application base directory.

  • At 0:00am and in case the log file exceeds 1GB, it is gz-compressed and renamed to core-of-tia-<n>.log.gz.

  • Up to 10 compressed log files will be kept before removal.

 

Info

Note: Utilities like logrotate for Linux (external link: https://linux.die.net/man/8/logrotate) provide similiar functionality on operating system level.

logrotate utility is not shipped with the tia Core cloud image and therefore not available forcloud deployment.