override log4j.properties in hadoop

Question

How do I override the default log4j.properties in hadoop? If I set the hadoop.root.logger=WARN,console, it doesnot print the logs on the console, whereas what I want is that it shouldn't print the INFO in the logs file. I added a log4j.properties file in my jar, but I am unable to override the default one. In short, I want the log file to print only the errors and warnings.

# Define some default values that can be overridden by system properties
hadoop.root.logger=INFO,console
hadoop.log.dir=.
hadoop.log.file=hadoop.log

#
# Job Summary Appender 
#
# Use following logger to send summary to separate file defined by 
# hadoop.mapreduce.jobsummary.log.file rolled daily:
# hadoop.mapreduce.jobsummary.logger=INFO,JSA
# 
hadoop.mapreduce.jobsummary.logger=${hadoop.root.logger}
hadoop.mapreduce.jobsummary.log.file=hadoop-mapreduce.jobsummary.log

# Define the root logger to the system property "hadoop.root.logger".
log4j.rootLogger=${hadoop.root.logger}, EventCounter

# Logging Threshold
log4j.threshold=ALL

#
# Daily Rolling File Appender
#

log4j.appender.DRFA=org.apache.log4j.DailyRollingFileAppender
log4j.appender.DRFA.File=${hadoop.log.dir}/${hadoop.log.file}

# Rollver at midnight
log4j.appender.DRFA.DatePattern=.yyyy-MM-dd

# 30-day backup
#log4j.appender.DRFA.MaxBackupIndex=30
log4j.appender.DRFA.layout=org.apache.log4j.PatternLayout

# Pattern format: Date LogLevel LoggerName LogMessage
log4j.appender.DRFA.layout.ConversionPattern=%d{ISO8601} %p %c: %m%n
# Debugging Pattern format
#log4j.appender.DRFA.layout.ConversionPattern=%d{ISO8601} %-5p %c{2} (%F:%M(%L)) - %m%n


#
# console
# Add "console" to rootlogger above if you want to use this 
#

log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.target=System.err
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss} %p %c{2}: %m%n

#
# TaskLog Appender
#

#Default values
hadoop.tasklog.taskid=null
hadoop.tasklog.iscleanup=false
hadoop.tasklog.noKeepSplits=4
hadoop.tasklog.totalLogFileSize=100
hadoop.tasklog.purgeLogSplits=true
hadoop.tasklog.logsRetainHours=12

log4j.appender.TLA=org.apache.hadoop.mapred.TaskLogAppender
log4j.appender.TLA.taskId=${hadoop.tasklog.taskid}
log4j.appender.TLA.isCleanup=${hadoop.tasklog.iscleanup}
log4j.appender.TLA.totalLogFileSize=${hadoop.tasklog.totalLogFileSize}

log4j.appender.TLA.layout=org.apache.log4j.PatternLayout
log4j.appender.TLA.layout.ConversionPattern=%d{ISO8601} %p %c: %m%n

#
#Security appender
#
hadoop.security.log.file=SecurityAuth.audit
log4j.appender.DRFAS=org.apache.log4j.DailyRollingFileAppender 
log4j.appender.DRFAS.File=${hadoop.log.dir}/${hadoop.security.log.file}

log4j.appender.DRFAS.layout=org.apache.log4j.PatternLayout
log4j.appender.DRFAS.layout.ConversionPattern=%d{ISO8601} %p %c: %m%n
#new logger
# Define some default values that can be overridden by system properties
hadoop.security.logger=INFO,console
log4j.category.SecurityLogger=${hadoop.security.logger}

#
# Rolling File Appender
#

#log4j.appender.RFA=org.apache.log4j.RollingFileAppender
#log4j.appender.RFA.File=${hadoop.log.dir}/${hadoop.log.file}

# Logfile size and and 30-day backups
#log4j.appender.RFA.MaxFileSize=1MB
#log4j.appender.RFA.MaxBackupIndex=30

#log4j.appender.RFA.layout=org.apache.log4j.PatternLayout
#log4j.appender.RFA.layout.ConversionPattern=%d{ISO8601} %-5p %c{2} - %m%n
#log4j.appender.RFA.layout.ConversionPattern=%d{ISO8601} %-5p %c{2} (%F:%M(%L)) - %m%n

#
# FSNamesystem Audit logging
# All audit events are logged at INFO level
#
log4j.logger.org.apache.hadoop.hdfs.server.namenode.FSNamesystem.audit=WARN

# Custom Logging levels

#log4j.logger.org.apache.hadoop.mapred.JobTracker=DEBUG
#log4j.logger.org.apache.hadoop.mapred.TaskTracker=DEBUG
#log4j.logger.org.apache.hadoop.hdfs.server.namenode.FSNamesystem.audit=DEBUG

# Jets3t library
log4j.logger.org.jets3t.service.impl.rest.httpclient.RestS3Service=ERROR

#
# Event Counter Appender
# Sends counts of logging messages at different severity levels to Hadoop Metrics.
#
log4j.appender.EventCounter=org.apache.hadoop.metrics.jvm.EventCounter

#
# Job Summary Appender
#
log4j.appender.JSA=org.apache.log4j.DailyRollingFileAppender
log4j.appender.JSA.File=${hadoop.log.dir}/${hadoop.mapreduce.jobsummary.log.file}
log4j.appender.JSA.layout=org.apache.log4j.PatternLayout
log4j.appender.JSA.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss} %p %c{2}: %m%n
log4j.appender.JSA.DatePattern=.yyyy-MM-dd
log4j.logger.org.apache.hadoop.mapred.JobInProgress$JobSummary=${hadoop.mapreduce.jobsummary.logger}
log4j.additivity.org.apache.hadoop.mapred.JobInProgress$JobSummary=false

#
# MapReduce Audit Log Appender
#

# Set the MapReduce audit log filename
#hadoop.mapreduce.audit.log.file=hadoop-mapreduce.audit.log

# Appender for AuditLogger.
# Requires the following system properties to be set
#    - hadoop.log.dir (Hadoop Log directory)
#    - hadoop.mapreduce.audit.log.file (MapReduce audit log filename)

#log4j.logger.org.apache.hadoop.mapred.AuditLogger=INFO,MRAUDIT
#log4j.additivity.org.apache.hadoop.mapred.AuditLogger=false
#log4j.appender.MRAUDIT=org.apache.log4j.DailyRollingFileAppender
#log4j.appender.MRAUDIT.File=${hadoop.log.dir}/${hadoop.mapreduce.audit.log.file}
#log4j.appender.MRAUDIT.DatePattern=.yyyy-MM-dd
#log4j.appender.MRAUDIT.layout=org.apache.log4j.PatternLayout
#log4j.appender.MRAUDIT.layout.ConversionPattern=%d{ISO8601} %p %c: %m%n

Answer 1

Modify the log4j file inside HADOOP_CONF_DIR. Note that hadoop job wont consider the log4j file of your application. It will consider the one inside HADOOP_CONF_DIR.

If you want to force hadoop to use some other log4j file, try one of these:

1. You can try what @Patrice said. ie.

   -Dlog4j.configuration=file:/path/to/user_specific/log4j.xml

2. Customize HADOOP_CONF_DIR/log4j.xml and set the logger level for "your" classes as per your wish. Other user(s) wont be affected due to this unless both are having classes with same package structure. This wont work for core hadoop classes as all users will get afftected.

3. Create your customized log4j file. Replicate the directory HADOOP_CONF_DIR and put your log4j file inside it. export HADOOP_CONF_DIR to your conf directory. Other users will point to the default one.

Answer 2

If you use the default Log4j.properties file the logging settings get overridden by environment variables from the startup script. If you want to use the default log4j and just simply want to change the logging level, use $HADOOP_CONF_DIR/hadoop-env.sh

For example, to change your logger to DEBUG log level and DRFA logger, use

export HADOOP_ROOT_LOGGER="DEBUG,DRFA"

Answer 3

1. You could remove the log4j.properties from your hadoop jar
2. OR make sure that your jar/log4j.properties is first in the classpath (log4j picks the first log4j.properties from the classpath that it finds)
3. OR specify the system variable: -Dlog4j.configuration=PATH_TO_FILE

See the documentation to learn how log4j finds the configuration.