Spark

1.  System.exit(0); to exit the spark shell.
2.  You don't have to start the Spark cluster (EMR) with  dynamicAllocation enabled to true.  You can always start the spark-shell with --conf spark.dynamicAllocation.enabled=true.  You can also pass --conf maximizeResourceAllocation=true.
3. You can customize logging for spark-submit by passing a custom log4j properties file: ( Assuming you are running in client mode on yarn cluster )

 --files ../log4j.properties --conf spark.driver.extraJavaOptions='-Dlog4j.configuration=file:
../log4j.properties'

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