diff options
| -rw-r--r-- | core/src/main/scala/org/apache/spark/rdd/RDD.scala | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/core/src/main/scala/org/apache/spark/rdd/RDD.scala b/core/src/main/scala/org/apache/spark/rdd/RDD.scala index e5fdebc65d..8bf4489e1a 100644 --- a/core/src/main/scala/org/apache/spark/rdd/RDD.scala +++ b/core/src/main/scala/org/apache/spark/rdd/RDD.scala @@ -85,10 +85,14 @@ abstract class RDD[T: ClassTag]( private def sc: SparkContext = { if (_sc == null) { throw new SparkException( - "RDD transformations and actions can only be invoked by the driver, not inside of other " + - "transformations; for example, rdd1.map(x => rdd2.values.count() * x) is invalid because " + - "the values transformation and count action cannot be performed inside of the rdd1.map " + - "transformation. For more information, see SPARK-5063.") + "This RDD lacks a SparkContext. It could happen in the following cases: \n(1) RDD " + + "transformations and actions are NOT invoked by the driver, but inside of other " + + "transformations; for example, rdd1.map(x => rdd2.values.count() * x) is invalid " + + "because the values transformation and count action cannot be performed inside of the " + + "rdd1.map transformation. For more information, see SPARK-5063.\n(2) When a Spark " + + "Streaming job recovers from checkpoint, this exception will be hit if a reference to " + + "an RDD not defined by the streaming job is used in DStream operations. For more " + + "information, See SPARK-13758.") } _sc } |