Loading data into an RDD
In this chapter, we will examine the different sources you can use for your RDD. If you decide to run it through the examples in the Spark shell, you can call .cache()
or .first()
on the RDDs you generate to check whether it can be loaded. In Chapter 2, Using the Spark Shell, you learned how to load data text from a file and from S3. In this chapter, we will look at the different formats of data (text file and CSV) and the different sources (filesystem and HDFS) supported.
One of the easiest ways to create an RDD is taking an existing Scala collection and converting it into an RDD. The SparkContext
object provides a function called parallelize
that takes a Scala collection and converts it into an RDD of the same type as the input collection, as shown here.
As mentioned in the previous chapters, cd
to the fdps-v3
directory and run spark-shell
or pyspark
.
For Scala, refer to the following screenshot:
For Java, refer to the following code:
import java.util.Arrays; ...