We know that partitioning and partitioners are the key components of Apache Spark. They influence how our data is partitioned, which means they influence where the data actually resides on which executors. If we have a good partitioner, then we will have good data locality, which will reduce shuffle. We know that shuffle is not desirable for processing, so reducing shuffle is crucial, and, therefore, choosing a proper partitioner is also crucial for our systems.
In this section, we will cover the following topics:
- Examining HashPartitioner
- Examining RangePartitioner
- Testing
We will first examine our HashPartitioner and RangePartitioner. We will then compare them and test the code using both the partitioners.
First we will create a UserTransaction array, as per the following example:
val keysWithValuesList =
Array(
UserTransaction("...