Spark - Error “A master URL must be set in your configuration” when submitting an app

Question

I have an Spark app which runs with no problem in local mode,but have some problems when submitting to the Spark cluster.

The error msg are as follows:

Answer 1

If you don't provide Spark configuration in JavaSparkContext then you get this error. That is: JavaSparkContext sc = new JavaSparkContext();

Solution: Provide JavaSparkContext sc = new JavaSparkContext(conf);