MapR 5.1 is at End of Life (EOL) and no longer supported. Please see the latest documentation. This documentation is not being updated.

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Use Pluggable Sorting Algorithms

MapR 5.1 Documentation

Use Pluggable Sorting Algorithms

Starting in version 3.0.2 of the MapR software, you can specify the DMExpress custom sorting algorithm from SyncSort for your MapReduce job. The JAR file dmxhadoop_mrv1_mapr.jar is installed along with DMExpress in the /lib subdirectory of your DMExpress installation directory.

NOTE:

Prerequisite

Before you use the DMExpress custom sorting algorithm, add the libMapRClient.so and libjvm.so to the LD_LIBRARY_PATH environment variable on each TaskTracker node and then restart Warden on each TaskTracker node.

To update the LD_LIBRARY_PATH, add the following text to opt/mapr/conf/env.sh file:export LD_LIBRARY_PATH=<full path to the directory libMapRClient.so>:<full path to the directory containing libjvm.so>:$LD_LIBRARY_PATH
To restart Warden, run the following commands: sudo service mapr-warden stop sudo service mapr-warden start