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https://issues.apache.org/jira/browse/SPARK-4882?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14260415#comment-14260415
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Apache Spark commented on SPARK-4882:
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User 'JoshRosen' has created a pull request for this issue:
https://github.com/apache/spark/pull/3831
> PySpark broadcast breaks when using KryoSerializer
> --------------------------------------------------
>
> Key: SPARK-4882
> URL: https://issues.apache.org/jira/browse/SPARK-4882
> Project: Spark
> Issue Type: Bug
> Components: PySpark
> Affects Versions: 1.1.1, 1.2.0, 1.3.0
> Reporter: Fi
> Assignee: Josh Rosen
>
> When KryoSerializer is used, PySpark will throw NullPointerException when
> trying to send broadcast variables to workers. This issue does not occur
> when the master is {{local}}, or when using the default JavaSerializer.
> *Reproduction*:
> Run
> {code}
> SPARK_LOCAL_IP=127.0.0.1 ./bin/pyspark --master local-cluster[2,2,512] --conf
> spark.serializer=org.apache.spark.serializer.KryoSerializer
> {code}
> then run
> {code}
> b = sc.broadcast("hello")
> sc.parallelize([0]).flatMap(lambda x: b.value).collect()
> {code}
> This job fails because all tasks throw the following exception:
> {code}
> 14/12/28 14:26:08 WARN TaskSetManager: Lost task 1.0 in stage 1.0 (TID 8,
> localhost): java.lang.NullPointerException
> at org.apache.spark.api.python.PythonRDD$.writeUTF(PythonRDD.scala:589)
> at
> org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1$$anonfun$apply$mcV$sp$3.apply(PythonRDD.scala:232)
> at
> org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1$$anonfun$apply$mcV$sp$3.apply(PythonRDD.scala:228)
> at scala.collection.Iterator$class.foreach(Iterator.scala:727)
> at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
> at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
> at scala.collection.AbstractIterable.foreach(Iterable.scala:54)
> at
> org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply$mcV$sp(PythonRDD.scala:228)
> at
> org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply(PythonRDD.scala:203)
> at
> org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply(PythonRDD.scala:203)
> at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1515)
> at
> org.apache.spark.api.python.PythonRDD$WriterThread.run(PythonRDD.scala:202)
> {code}
> KryoSerializer may be enabled in the {{spark-defaults.conf}} file, so users
> may hit this error and be confused.
> *Workaround*:
> Override the {{spark.serializer}} setting to use the default Java serializer.
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