Spark 异常汇总（持续更新）

Only one SparkContext may be running in this JVM (see SPARK-2243). To ignore this error, set spark.driver.allowMultipleContexts = true. The currently running SparkContext was created at: org.apache.spark.SparkContext.<init>(SparkContext.scala:82) com.demo.sadsa.SparkDemo(sadsa.scala:26) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 

原因：

尝试在已启动SparkContext的相同JVM中实例化另一个SparkContext时，SparkContext构造函数将引发异常。

解决方法：spark.driver.allowMultipleContexts = true关闭异常。