1. Warning about Java 9 and Spark2.3!

IMPORTANT SETUP NOTE

You're about to install Apache Spark, a powerful technology for analyzing big data!

When you're installing a Java Development Kit (JDK) for Spark, do not install Java 9. Scroll down a little and install the JDK for Java 8 instead.

Java 9 just came out recently, and Spark is not yet compatible with it.

Also when downloading Apache Spark itself, download the latest Spark 2.2 package. Do not install Spark 2.3 or newer - one of the third party libraries we use in this course is only compatible up to Spark 2.2.