[Spark] Basics of SparkSession

 

SparkSession = SparkContext + HiveContext + StreamingContext + SQLContext

 

val conf = new SparkConf().setMaster("master").setAppName("appName1")
val sc = new SparkContext(conf)  //或者val sc = new SparkContext("master","appName1")

Once SparkConf is set, it cannot be modified, and the settings are stored in ConcurrentHashMap