Howto: Adjust hive client logging level without restarting components

[#1]

It would sometimes be useful to adjust the log level when executing hive commands from command line without having to restart components. This article explains how that can be achieved:

You can provide the log level on the command line to hive as follows

hive -hiveconf hive.root.logger=DEBUG,console -e "show tables ;"

For example:

# hive -hiveconf hive.root.logger=DEBUG,console -e "show tables ;" |more

16/12/24 15:10:23 DEBUG util.VersionInfo: version: 2.7.3.2.5.3.0-37
16/12/24 15:10:27 [main]: DEBUG common.LogUtils: Using hive-site.xml found on CLASSPATH at /etc/hive/2.5.3.0-37/0/hive-site.xml
16/12/24 15:10:27 [main]: DEBUG session.SessionState: SessionState user: null
Logging initialized using configuration in file:/etc/hive/2.5.3.0-37/0/hive-log4j.properties
16/12/24 15:10:27 [main]: INFO SessionState: 
Logging initialized using configuration in file:/etc/hive/2.5.3.0-37/0/hive-log4j.properties
16/12/24 15:10:27 [main]: DEBUG parse.VariableSubstitution: Substitution is on: hive
16/12/24 15:10:27 [main]: DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginSuccess with annotation @org.apache.hadoop.metrics2.annotation.Metric(about=, sampleName=Ops, always=false, type=DEFAULT, valueName=Time, value=[Rate of successful kerberos logins and latency (milliseconds)])
16/12/24 15:10:27 [main]: DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginFailure with annotation @org.apache.hadoop.metrics2.annotation.Metric(about=, sampleName=Ops, always=false, type=DEFAULT, valueName=Time, value=[Rate of failed kerberos logins and latency (milliseconds)])
16/12/24 15:10:27 [main]: DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.getGroups with annotation @org.apache.hadoop.metrics2.annotation.Metric(about=, sampleName=Ops, always=false, type=DEFAULT, valueName=Time, value=[GetGroups])

This can be especially useful if your hive cli is hanging or slow connecting.

Note, the following log levels are supported: ALL DEBUG ERROR FATAL INFO OFF TRACE TRACE_INT WARN