Problem Definition

Starting from Bamboo 7.0 onwards, the default size of atlassian-bamboo.log is increased to 100mb from 25mb and maximum files to retain is still just 5.

In busy instances, the server cannot hold sufficient logs as they are removed from the default directory after retaining the last 5 logs.

#using 'bamboo home aware' appender. If the File is relative a relative Path the file goes into {bamboo.home}/logs
log4j.appender.filelog=com.atlassian.bamboo.log.BambooRollingFileAppender
log4j.appender.filelog.File=atlassian-bamboo.log
log4j.appender.filelog.MaxFileSize=100MB
log4j.appender.filelog.MaxBackupIndex=5
log4j.appender.filelog.layout=org.apache.log4j.PatternLayout
log4j.appender.filelog.layout.ConversionPattern=%d %p [%t] [%c{1}] %m%n

Suggested Solution

To retain the server log history, it is best to retain at least 20 logs like the solution below or increase the file size to 200mb in log4j.properties.

#using 'bamboo home aware' appender. If the File is relative a relative Path the file goes into {bamboo.home}/logs
log4j.appender.filelog=com.atlassian.bamboo.log.BambooRollingFileAppender
log4j.appender.filelog.File=atlassian-bamboo.log
log4j.appender.filelog.MaxFileSize=100MB
log4j.appender.filelog.MaxBackupIndex=20
log4j.appender.filelog.layout=org.apache.log4j.PatternLayout
log4j.appender.filelog.layout.ConversionPattern=%d %p [%t] [%c{1}] %m%n

Why this is important

Due to the current default setup, one can no longer track logs above 500mb on what happened on a busy server especially when DEBUG is enabled in some classes. as the limit of 5 files are removed already by default.

Workaround

After upgrading Bamboo to 7.0 or above, ensure that the value of log4j.appender.filelog.MaxBackupIndex is increased in <Bamboo-Install>/atlassian-bamboo/WEB-INF/classes/log4j.properties file.