CODE EXAMPLE FOR SHELL

Swappiness setting recommendation swap sysctl.conf performance improvement Hadoop system

# To change the swappiness on a running machine, use the following command:
echo "1" > /proc/sys/vm/swappiness

# To ensure the swappiness is set appropriately on reboot, use the following command:
echo "vm.swappiness=1" >> /etc/sysctl.conf

# NOTE: Virtual Memory swapping can have a large impact on the performance of a Hadoop system. 
# Because of the memory requirements of YARN containers and processes running on the nodes in the cluster.
# The swapping process out of memory to disk can cause serious performance limitations.