Spark Shell — `spark-shell` shell script

Spark shell is an interactive shell to learn how to make the most out of Apache Spark that ultimately should help you to develop your own standalone Spark applications. It is a very convenient tool to explore the many things available in Spark and one of the many reasons why Spark is so helpful even for tasks of any size.

There are variants of Spark shell for different languages: spark-shell for Scala and pyspark for Python.

Note	This document uses `spark-shell` only and this is your very first Spark application written in Scala that you should use early and often.

You can start Spark shell for Scala using spark-shell script.

$ ./bin/spark-shell
scala>

spark-shell is an extension of Scala REPL with automatic instantiation of SparkSession as spark (and SparkContext as sc).

scala> :type spark
org.apache.spark.sql.SparkSession

Note	When you execute `spark-shell` it executes Spark submit as follows: `org.apache.spark.deploy.SparkSubmit --class org.apache.spark.repl.Main --name Spark shell spark-shell` Set `SPARK_PRINT_LAUNCH_COMMAND` to see the entire command to be executed. Refer to Print Launch Command of Spark Scripts.

Spark shell boils down to executing Spark submit and so command-line arguments of Spark submit become Spark shell’s, e.g. --verbose.

Using Spark shell

You start Spark shell using spark-shell script (available in bin directory).

$ ./bin/spark-shell
Setting default log level to "WARN".
To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel).
WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
WARN ObjectStore: Failed to get database global_temp, returning NoSuchObjectException
Spark context Web UI available at http://10.47.71.138:4040
Spark context available as 'sc' (master = local[*], app id = local-1477858597347).
Spark session available as 'spark'.
Welcome to
      ____              __
     / __/__  ___ _____/ /__
    _\ \/ _ \/ _ `/ __/  '_/
   /___/ .__/\_,_/_/ /_/\_\   version 2.1.0-SNAPSHOT
      /_/

Using Scala version 2.11.8 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_112)
Type in expressions to have them evaluated.
Type :help for more information.

scala>

Spark shell creates an instance of SparkSession under the name spark for you (so you don’t have to know the details how to do it yourself on day 1).

scala> :type spark
org.apache.spark.sql.SparkSession

Besides, there is also sc value created which is an instance of SparkContext.

scala> :type sc
org.apache.spark.SparkContext

To close Spark shell, you press Ctrl+D or type in :q (or any subset of :quit).

scala> :quit

Settings

Table 1. Spark Properties
Spark Property	Default Value	Description
`spark.repl.class.uri`	`null`	Used in `spark-shell` to create REPL ClassLoader to load new classes defined in the Scala REPL as a user types code. Enable `INFO` logging level for org.apache.spark.executor.Executor logger to have the value printed out to the logs: `INFO Using REPL class URI: [classUri]`

Spark Shell — spark-shell shell script