Spark configure.sh
Starting in the EEP 4.0 release, run
      configure.sh -R to complete your Spark configuration when manually installing
    Spark or upgrading to a new version. 
The command is the following:
/opt/mapr/server/configure.sh -R
    In the case of Spark Standalone and Spark on YARN, this is the last step in the configuration process.
SPARK_HOME/conf/spark-defaults.conf
      file:#SECURITY BLOCK
...
#END OF THE SECURITY CONFIGURATION BLOCKDo not remove these comments from the file, as well as any other comments within the block
      inserted by configure.sh. The script uses these comments to locate security
      properties.
To set ports to special values, use the spark.driver.port and
        spark.blockManager.port properties.
Starting in EEP 6.0.0, Spark services such as the
      History Server, Thrift Server, or Primary are restarted by configure.sh only
      for changes to the following Spark configuration files: spark-defaults.conf,
        spark-env.sh, hive-site.xml, or
        log4j.properties. If these files are unchanged,
        configure.sh does not restart any of the Spark services.
An update to Spark causes the conf directory from the previous the Spark
      version to be saved to the spark-<old-version>.<old-timestamp>
      directory. If your Spark version did not change during the update, then configurations from
      the spark-<old-version>.<old-timestamp> directory is automatically
      copied to the spark-<version> directory by the
        configure.sh script.
If you use .customSecure, at the first run, the
        configure.sh script copies the hive-site.xml file from
      Hive. For subsequent times, the hive-site.xml file is not copied from Hive
      and you would need to manually modify the $SPARK_HOME/conf/hive-site.xml
      file.