Enabling UseNUMA flag for hadoop?

I wish to enable UseNUMA flag for my hadoop framework which uses java.

The problem is I don't know which all places java command has been called by hadoop framework.

So, I've written alias for java command in /etc/bash.bashrc as

alias java='java -XX:+UseNUMA'

Is it the right way to do it?

How will I know if the flag is turned on or not? I mean can check this using following command

# java -XX:+PrintFlagsFinal | grep UseNUMA

But how to check if hadoop is using it or not?


Creating an alias in bashrc won't be useful. Hadoop uses the environment variable JAVA_HOME for locating java home, java command is taken from the path ${JAVA_HOME}/bin/java. So even if you create an alias in your .bashrc, will be useless.

For specifying JVM flags during hadoop daemon's starts, make use of the configuration file /hadoop-env.sh specify the flags in the environment variable.

export HADOOP_NAMENODE_OPTS="-XX:+UseNUMA -Dcom.sun.management.jmxremote $HADOOP_NAMENODE_OPTS"
export HADOOP_DATANODE_OPTS="-XX:+UseNUMA -Dcom.sun.management.jmxremote $HADOOP_DATANODE_OPTS"
export HADOOP_BALANCER_OPTS="-XX:+UseNUMA -Dcom.sun.management.jmxremote $HADOOP_BALANCER_OPTS"
export HADOOP_JOBTRACKER_OPTS="-XX:+UseNUMA -Dcom.sun.management.jmxremote $HADOOP_JOBTRACKER_OPTS"

Enabling the same in Client side while executing the co like hadoop,yarn,mapred use the following environment variable


For checking the flag is enabled or not, following command can be used.

ps aux | grep hadoop

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