[ 
https://issues.apache.org/jira/browse/SPARK-1630?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14077492#comment-14077492
 ] 

Josh Rosen commented on SPARK-1630:
-----------------------------------

In the current Spark codebase, the PythonRDD constructor is only called from 
Python code.  In order for a user-created Scala/Java RDD<String> to be passed 
to PySpark, the user would need to have dug deep into PySpark's private APIs to 
call out to Java/Scala code to create a transformed RDD and wrap it into a 
PythonRDD.  Given this, is it fair to say that any in-the-wild NPEs encountered 
here by using Spark's public APIs are due to bugs in Spark/PySpark, or is there 
a case that I'm overlooking (e.g. is TextInputFormat allowed to return nulls?)?

> PythonRDDs don't handle nulls gracefully
> ----------------------------------------
>
>                 Key: SPARK-1630
>                 URL: https://issues.apache.org/jira/browse/SPARK-1630
>             Project: Spark
>          Issue Type: Bug
>          Components: PySpark, SQL
>    Affects Versions: 0.9.0, 0.9.1
>            Reporter: Kalpit Shah
>            Assignee: Davies Liu
>   Original Estimate: 2h
>  Remaining Estimate: 2h
>
> If PythonRDDs receive a null element in iterators, they currently NPE. It 
> would be better do log a DEBUG message and skip the write of NULL elements.
> Here are the 2 stack traces :
> 14/04/22 03:44:19 ERROR executor.Executor: Uncaught exception in thread 
> Thread[stdin writer for python,5,main]
> java.lang.NullPointerException
>   at 
> org.apache.spark.api.python.PythonRDD$.writeIteratorToStream(PythonRDD.scala:267)
>   at org.apache.spark.api.python.PythonRDD$$anon$2.run(PythonRDD.scala:88)
> -------------------------------------------------------------------------------------
> Py4JJavaError: An error occurred while calling 
> z:org.apache.spark.api.python.PythonRDD.writeToFile.
> : java.lang.NullPointerException
>   at org.apache.spark.api.python.PythonRDD$.writeUTF(PythonRDD.scala:273)
>   at 
> org.apache.spark.api.python.PythonRDD$$anonfun$writeIteratorToStream$2.apply(PythonRDD.scala:247)
>   at 
> org.apache.spark.api.python.PythonRDD$$anonfun$writeIteratorToStream$2.apply(PythonRDD.scala:246)
>   at scala.collection.Iterator$class.foreach(Iterator.scala:727)
>   at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
>   at 
> org.apache.spark.api.python.PythonRDD$.writeIteratorToStream(PythonRDD.scala:246)
>   at org.apache.spark.api.python.PythonRDD$.writeToFile(PythonRDD.scala:285)
>   at org.apache.spark.api.python.PythonRDD$.writeToFile(PythonRDD.scala:280)
>   at org.apache.spark.api.python.PythonRDD.writeToFile(PythonRDD.scala)
>   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>   at 
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
>   at 
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
>   at java.lang.reflect.Method.invoke(Method.java:606)
>   at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:231)
>   at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:379)
>   at py4j.Gateway.invoke(Gateway.java:259)
>   at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
>   at py4j.commands.CallCommand.execute(CallCommand.java:79)
>   at py4j.GatewayConnection.run(GatewayConnection.java:207)
>   at java.lang.Thread.run(Thread.java:744)  



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Reply via email to