How to set Master address for Spark examples from command line

One approach to resolve your errors is that you can set the Spark master from the command-line by adding the JVM parameter:

    -Dspark.master=spark://myhost:7077

Also, if you want to get this done from code you can use .setMaster(...) when creating the SparkConf:

val conf = new SparkConf().setAppName("Simple Application")
                          .setMaster("spark://myhost:7077")
And for Spark 2.x + do:
val spark = SparkSession.builder()
                        .appName("app_name")
                        .getOrCreate()