$ ./bin/spark-shell
scala>
Spark Shell — spark-shell shell script
Spark shell is an interactive shell to learn how to make the most out of Apache Spark. This is a Spark application writted in Scala to offer a command-line environment with auto-completion (under TAB
key) where you can run ad-hoc queries and get familiar with the features of Spark (that help you in developing your own standalone Spark applications). It is a very convenient tool to explore the many things available in Spark with immediate feedback. It is one of the many reasons why Spark is so helpful for tasks to process datasets of any size.
There are variants of Spark shell for different languages: spark-shell
for Scala and pyspark
for Python.
Note
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This document uses spark-shell only.
|
You can start Spark shell using spark-shell
script.
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
// Learn the current version of Spark in use
scala> spark.version
res0: String = 2.1.0-SNAPSHOT
spark-shell
also imports Scala SQL’s implicits and sql
method.
scala> :imports
1) import spark.implicits._ (59 terms, 38 are implicit)
2) import spark.sql (1 terms)
Note
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When you execute org.apache.spark.deploy.SparkSubmit --class org.apache.spark.repl.Main --name Spark shell spark-shell Set |
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> :q
Settings
Spark Property | Default Value | Description |
---|---|---|
|
Used in Enable
|