Use Local Volume for Temporary Sort Data Directory

Using a single disk to store temporary sort data can impose performance challenges for your MapR cluster. To prevent this issue, mount the local volume to the local file system and set that directory as the temporary sort data directory. The MapR filesystem can then take advantage of all the disks that are available on the node, resulting in improved performance.

To take advantage of this performance boost, your cluster must have a MapR license that enables multiple NFS servers. All nodes on the cluster must have the mapr-nfs package installed and be running the mapr-nfs service.

The following sample script performs the NFS mount:

echo "Mount Each Node's emptydir: $localNFSMountDir to local volume: $nodeName:/mapr/perf/var/mapr/local/$nodeName/mapred"
    ssh $i "umount -l $localNFSMountDir"
    ssh $i "mount -t nfs ${nodeName}:/mapr/perf/var/mapr/local/${nodeName}/mapred ${localNFSMountDir}"