title: SparkException: Python worker did not connect back in time
body: <p>I am trying to submit a Python job to a 2 worker node Spark cluster but am persistently seeing the following problem, which eventually causes spark-submit to fail:</p>
  
  <pre><code>15/07/04 21:30:40 WARN scheduler.TaskSetManager: Lost task 0.1 in stage 0.0 (TID
   2, workernode0.rhom-spark.b9.internal.cloudapp.net):    
  org.apache.spark.SparkException: Python worker did not connect back in time
      at org.apache.spark.api.python.PythonWorkerFactory.createSimpleWorker(PythonWorkerFactory.scala:135)
      at org.apache.spark.api.python.PythonWorkerFactory.create(PythonWorkerFactory.scala:64)
      at org.apache.spark.SparkEnv.createPythonWorker(SparkEnv.scala:102)
      at org.apache.spark.api.python.PythonRDD.compute(PythonRDD.scala:70)
      at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:278)
      at org.apache.spark.rdd.RDD.iterator(RDD.scala:245)
      at org.apache.spark.api.python.PairwiseRDD.compute(PythonRDD.scala:305)
      at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:278)
      at org.apache.spark.rdd.RDD.iterator(RDD.scala:245)
      at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:68)
      at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:41)
      at org.apache.spark.scheduler.Task.run(Task.scala:56)
      at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:200)
  
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
      at java.lang.Thread.run(Thread.java:745)
  Caused by: java.net.SocketTimeoutException: Accept timed out
      at java.net.DualStackPlainSocketImpl.waitForNewConnection(Native Method)
  
      at java.net.DualStackPlainSocketImpl.socketAccept(DualStackPlainSocketImpl.java:135)
      at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:398)
      at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:199)
      at java.net.ServerSocket.implAccept(ServerSocket.java:530)
      at java.net.ServerSocket.accept(ServerSocket.java:498)
      at org.apache.spark.api.python.PythonWorkerFactory.createSimpleWorker(PythonWorkerFactory.scala:130)
      ... 15 more
  </code></pre>
  
  <p>I'm submitting the job with the following</p>
  
  <pre><code>spark-submit --master yarn --py-files tile.py --num-executors 1 --executor-memory 2g main.py
  </code></pre>
  
  <p>Any ideas?</p>