Scala and Spark for Big Data Analytics

collect

collect() simply collects all elements in the RDD and sends it to the Driver.

Shown here is an example showing what collect function essentially does. When you call collect on an RDD, the Driver collects all the elements of the RDD by pulling them into the Driver.

Calling collect on large RDDs will cause out-of-memory issues on the Driver.

Shown below is the code to collect the content of the RDD and display it:

scala> rdd_two.collectres25: Array[String] = Array(Apache Spark provides programmers with an application programming interface centered on a data structure called the resilient distributed dataset (RDD), a read-only multiset of data items distributed over a cluster of machines, that is maintained in a fault-tolerant way., ...