[MAPREDUCE-3408] yarn-daemon.sh unconditionnaly sets yarn.root.logger

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.23.0, 0.23.1
• Fix Version/s: 0.23.1
• Component/s: mrv2, nodemanager, resourcemanager
• Labels: bigtop
• Hadoop Flags: Reviewed
• Assignee: Bruno Mahé
• Reporter: Bruno Mahé
• Created: 16/Nov/11 01:35
• Updated: 05/Mar/12 02:48
• Resolved: 22/Nov/11 22:36

Description

yarn-daemon.sh unconditionnaly sets yarn.root.logger which then prevent any override from happening.
From ./hadoop-mapreduce-project/hadoop-yarn/bin/yarn-daemon.sh:
> export YARN_ROOT_LOGGER="INFO,DRFA"
> export YARN_JHS_LOGGER="INFO,JSA"

and then yarn-daemon.sh will call "$YARN_HOME"/bin/yarn which does the following:
> YARN_OPTS="$YARN_OPTS -Dhadoop.root.logger=${YARN_ROOT_LOGGER:-INFO,console}"
> YARN_OPTS="$YARN_OPTS -Dyarn.root.logger=${YARN_ROOT_LOGGER:-INFO,console}"

This has at least 2 issues:

• I cannot override hadoop.root.logger when using the yarn-daemon.sh script
• I cannot have different values for hadoop.root.logger and yarn.root.logger

I currently see two different ways to proceed forward:
1/ Make the script yarn-daemon.sh only sets a default value for YARN_ROOT_LOGGER if this variable is not defined
2/ Remove the quoted code from yarn-daemon.sh since yarn already does something similar
3/ Entirely remove that chunk and let people define their logging however they want through some properties files (see log4j.properties in the conf directories for instance)

I would also use the variable HADOOP_ROOT_LOGGER for hadoop.root.logger if either option 1/ or 2/ would be taken.

I don't really have any preference toward any of these solutions. What would you recommend? What is the Apache Hadoop way for this matter?

Note: This is probably happening as well for the other daemons, and I will take a look at it once this issue is resolved.