Spark internals through code
Nothing gives you more detail about spark internals than actually reading it source code. In addition, you get to learn many design techniques and improve your scala coding skills. These are the random notes I make while reading the spark code. The best way to comprehend the notes is to load spark code into an IDE, e.g. IntelliJ, and navigate the code on the side.
The scripts for creating a spark cluster are: start-master.sh and start-slave.sh. Read them carefully, and you can see that both scripts are very similar except the values for $CLASS variable. For start-master.sh, the value is CLASS="org.apache.spark.deploy.master.Master", while the value for start-slave.sh is shown below with more context.
# NOTE: This exact class name is matched downstream by SparkSubmit.