Cannot change zookeeper log filename - log4j

Question

Zookeeper is creating the logs with a name zookeeper-root-hostname.out but this is my log4j.properties:
zookeeper.root.logger=INFO, CONSOLE
zookeeper.console.threshold=INFO
zookeeper.log.dir=.
zookeeper.log.file=zookeeper.log
zookeeper.log.threshold=INFO
zookeeper.log.maxfilesize=256MB
zookeeper.log.maxbackupindex=20
zookeeper.tracelog.dir=${zookeeper.log.dir}
zookeeper.tracelog.file=zookeeper_trace.log
log4j.rootLogger=${zookeeper.root.logger}
#
# console
# Add "console" to rootlogger above if you want to use this
#
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Threshold=${zookeeper.console.threshold}
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%d{ISO8601} [myid:%X{myid}] - %-5p [%t:%C{1}#%L] - %m%n
#
# Add ROLLINGFILE to rootLogger to get log file output
#
log4j.appender.ROLLINGFILE=org.apache.log4j.RollingFileAppender
log4j.appender.ROLLINGFILE.Threshold=${zookeeper.log.threshold}
log4j.appender.ROLLINGFILE.File=${zookeeper.log.dir}/${zookeeper.log.file}
log4j.appender.ROLLINGFILE.MaxFileSize=${zookeeper.log.maxfilesize}
log4j.appender.ROLLINGFILE.MaxBackupIndex=${zookeeper.log.maxbackupindex}
log4j.appender.ROLLINGFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.ROLLINGFILE.layout.ConversionPattern=%d{ISO8601} [myid:%X{myid}] - %-5p [%t:%C{1}#%L] - %m%n
If a change the property zookeeper.log.file=zookeeper.log the file is created with the same name, How can I change the filename of the log?
Update
I found that the file zkServer.sh set the variable ZOO_LOG_FILE and overrides the value that is define in the log4j.properties:
ZOO_LOG_FILE=zookeeper-$USER-server-$HOSTNAME.log
I can modify this file but Is it ok to change that manually?

Answer 1

In typical Java application fashion the logging situation with Zookeeper is incredibly complicated, custom, and poorly documented. The official Administrators manual logging section is a tiny paragraph with about zero information, but suggests you can rely on your existing knowledge of the third party library log4j configured to proxy through the other third party library SLF4J. This actually wouldn't be too bad since that complicated arrangement is common as many popular open source projects ignore the built-in logging framework that ships will Java, but later you'll discover using the log4j.properties file in the conf directory actually doesn't work as expected because custom properties are used in the provided start up script (zkServer.sh) that override many things.
In order to set the file name note the file conf/log4j.properties contains the following variable assignment that is overridden by the start up script (zkServer.sh):
zookeeper.log.file=zookeeper.log
Either set the environment variables externally, modify the start up script or update the log4j.properties to not use the variable:
#log4j.appender.ROLLINGFILE.File=${zookeeper.log.dir}/${zookeeper.log.file}
log4j.appender.ROLLINGFILE.File=/the/actual/path/goes/here.log
You may also want to enable the ROLLINGFILE like so:
#log4j.rootLogger=${zookeeper.root.logger}
log4j.rootLogger=INFO,ROLLINGFILE

Answer 2

After searching I found this link but I didn't found how to change the variable for the log, I noticed that inside the file zkServer.sh is defined the name of the file, so I needed to change this variable:
_ZOO_DAEMON_OUT="$ZOO_LOG_DIR/zookeeper-$USER-server-$HOSTNAME.out"
I don't know if it's ok to change that variable but now is working as expected.