add docs

apache · Jan 11, 2018 · cea2ddc · cea2ddc
1 parent b5d621b
commit cea2ddc
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diff --git a/...ala/org/apache/spark/sql/execution/streaming/continuous/ContinuousDataSourceRDDIter.scala b/...ala/org/apache/spark/sql/execution/streaming/continuous/ContinuousDataSourceRDDIter.scala
@@ -52,6 +52,7 @@ class ContinuousDataSourceRDD(
   }
 
   override def compute(split: Partition, context: TaskContext): Iterator[UnsafeRow] = {
+    // If attempt number isn't 0, this is a task retry, which we don't support.
     if (context.attemptNumber() != 0) {
       throw new ContinuousTaskRetryException()
     }

diff --git a/...la/org/apache/spark/sql/execution/streaming/continuous/ContinuousTaskRetryException.scala b/...la/org/apache/spark/sql/execution/streaming/continuous/ContinuousTaskRetryException.scala
@@ -19,5 +19,8 @@ package org.apache.spark.sql.execution.streaming.continuous
 
 import org.apache.spark.SparkException
 
+/**
+ * An exception thrown when a continuous processing task runs with a nonzero attempt ID.
+ */
 class ContinuousTaskRetryException
   extends SparkException("Continuous execution does not support task retry", null)