Github user guowei2 commented on a diff in the pull request:

    https://github.com/apache/spark/pull/1291#discussion_r14498644
  
    --- Diff: 
streaming/src/main/scala/org/apache/spark/streaming/dstream/ShuffledDStream.scala
 ---
    @@ -39,8 +39,10 @@ class ShuffledDStream[K: ClassTag, V: ClassTag, C: 
ClassTag](
     
       override def compute(validTime: Time): Option[RDD[(K,C)]] = {
         parent.getOrCompute(validTime) match {
    -      case Some(rdd) => Some(rdd.combineByKey[C](
    -          createCombiner, mergeValue, mergeCombiner, partitioner, 
mapSideCombine))
    +      case Some(rdd) => {
    +        Some(if (rdd.partitions.length==0) 
rdd.combineByKey(createCombiner, mergeValue, mergeCombiner,0)
    --- End diff --
    
    1、for example:
    u use NetworkInputDStream to receive data to generate BlockRDD.  when it 
receive no blocks in validtime, then partitions will be 0
    
    NetworkInputDStream's code here 
    
      override def compute(validTime: Time): Option[RDD[T]] = {
        // If this is called for any time before the start time of the context,
        // then this returns an empty RDD. This may happen when recovering from 
a
        // master failure
        if (validTime >= graph.startTime) {
          val blockIds = ssc.scheduler.networkInputTracker.getBlockIds(id, 
validTime)
          Some(new BlockRDD[T](ssc.sc, blockIds))
        } else {
          Some(new BlockRDD[T](ssc.sc, Array[BlockId]()))
        }
      }
    
    2.  when parent RDD partition num  is 0 ,but  ShuffledDStream also change 
into muti-partitions ,
    then emtpy job will be running.
      
          what i do is when this happen ShuffledDStream also out 0 partition


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