«rdd.count ()» работает, но «rdd.first ()» не работает с Py4J Java Ошибка в записной книжке Jupyter - PullRequest
0 голосов
/ 04 мая 2020

Я совершенно новичок в Spark. Я использую версию Spark 2.3 и Python версию 3.7. На Windows 10, кстати. Я запускаю Jupyter Notebook для выполнения операций PySpark. Я изучаю курс Pluralsight (начало работы с Spark 2.0)

Я запускаю pyspark в Jupyter, используя следующие команды в командной строке Anaconda:

set PYSPARK_DRIVER_PYTHON = jupyter set PYSPARK_DRIVER_PYTHON_OPTS = ноутбук pyspark

После того, как ноутбук открывается:

Я запускаю следующие команды:

sc

from pyspark.sql.types import Row
from datetime import datetime

simple_data = sc.parallelize([1, "Alice", 50])
simple_data

simple_data.count()

simple_data.first()

Теперь, вот где это терпит неудачу: simple_data.first() с нижеуказанной ошибкой :

Py4JJavaError                             Traceback (most recent call last)
<ipython-input-5-cc577dea1d9b> in <module>
----> 1 simple_data.first()

    C:\spark\python\pyspark\rdd.py in first(self)
   1374         ValueError: RDD is empty
   1375         """
-> 1376         rs = self.take(1)
   1377         if rs:
   1378             return rs[0]

C:\spark\python\pyspark\rdd.py in take(self, num)
   1356 
   1357             p = range(partsScanned, min(partsScanned + numPartsToTry, totalParts))
-> 1358             res = self.context.runJob(self, takeUpToNumLeft, p)
   1359 
   1360             items += res

C:\spark\python\pyspark\context.py in runJob(self, rdd, partitionFunc, partitions, allowLocal)
    999         # SparkContext#runJob.
   1000         mappedRDD = rdd.mapPartitions(partitionFunc)
-> 1001         port = self._jvm.PythonRDD.runJob(self._jsc.sc(), mappedRDD._jrdd, partitions)
   1002         return list(_load_from_socket(port, mappedRDD._jrdd_deserializer))
   1003 

C:\spark\python\lib\py4j-0.10.6-src.zip\py4j\java_gateway.py in __call__(self, *args)
   1158         answer = self.gateway_client.send_command(command)
   1159         return_value = get_return_value(
-> 1160             answer, self.gateway_client, self.target_id, self.name)
   1161 
   1162         for temp_arg in temp_args:

C:\spark\python\pyspark\sql\utils.py in deco(*a, **kw)
     61     def deco(*a, **kw):
     62         try:
---> 63             return f(*a, **kw)
     64         except py4j.protocol.Py4JJavaError as e:
     65             s = e.java_exception.toString()

C:\spark\python\lib\py4j-0.10.6-src.zip\py4j\protocol.py in get_return_value(answer, gateway_client, target_id, name)
    318                 raise Py4JJavaError(
    319                     "An error occurred while calling {0}{1}{2}.\n".
--> 320                     format(target_id, ".", name), value)
    321             else:
    322                 raise Py4JError(

Py4JJavaError: An error occurred while calling z:org.apache.spark.api.python.PythonRDD.runJob.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 1.0 failed 1 times, most recent failure: Lost task 0.0 in stage 1.0 (TID 4, localhost, executor driver): org.apache.spark.api.python.PythonException: Traceback (most recent call last):
  File "C:\spark\python\pyspark\rdd.py", line 1354, in takeUpToNumLeft
    yield next(iterator)
StopIteration

Это большой журнал ошибок, чем я вставил сюда. Я искал возможные решения и обновил Java jdk, используя conda install -c cyclus java-jdk, но даже после этого ничего не изменилось.

Я немного застрял и не могу продолжить свой курс. Почему это работает для .count(), но не для .first() Как устранить эту ошибку? Чего мне не хватает?

Добавление полного сообщения об ошибке после опробования предложения @ Sparker0i в ответе:

Py4JJavaError                             Traceback (most recent call last)
<ipython-input-3-4dbbd81a7c5c> in <module>
      2 #simple_data
      3 
----> 4 simple_data = sc.parallelize([[1, "Alice", 50]]).toDF()
      5 simple_data.count()
      6 simple_data.first()

C:\spark\python\pyspark\sql\session.py in toDF(self, schema, sampleRatio)
     56         [Row(name=u'Alice', age=1)]
     57         """
---> 58         return sparkSession.createDataFrame(self, schema, sampleRatio)
     59 
     60     RDD.toDF = toDF

C:\spark\python\pyspark\sql\session.py in createDataFrame(self, data, schema, samplingRatio, verifySchema)
    685 
    686         if isinstance(data, RDD):
--> 687             rdd, schema = self._createFromRDD(data.map(prepare), schema, samplingRatio)
    688         else:
    689             rdd, schema = self._createFromLocal(map(prepare, data), schema)

C:\spark\python\pyspark\sql\session.py in _createFromRDD(self, rdd, schema, samplingRatio)
    382         """
    383         if schema is None or isinstance(schema, (list, tuple)):
--> 384             struct = self._inferSchema(rdd, samplingRatio, names=schema)
    385             converter = _create_converter(struct)
    386             rdd = rdd.map(converter)

C:\spark\python\pyspark\sql\session.py in _inferSchema(self, rdd, samplingRatio, names)
    353         :return: :class:`pyspark.sql.types.StructType`
    354         """
--> 355         first = rdd.first()
    356         if not first:
    357             raise ValueError("The first row in RDD is empty, "

C:\spark\python\pyspark\rdd.py in first(self)
   1374         ValueError: RDD is empty
   1375         """
-> 1376         rs = self.take(1)
   1377         if rs:
   1378             return rs[0]

C:\spark\python\pyspark\rdd.py in take(self, num)
   1356 
   1357             p = range(partsScanned, min(partsScanned + numPartsToTry, totalParts))
-> 1358             res = self.context.runJob(self, takeUpToNumLeft, p)
   1359 
   1360             items += res

C:\spark\python\pyspark\context.py in runJob(self, rdd, partitionFunc, partitions, allowLocal)
    999         # SparkContext#runJob.
   1000         mappedRDD = rdd.mapPartitions(partitionFunc)
-> 1001         port = self._jvm.PythonRDD.runJob(self._jsc.sc(), mappedRDD._jrdd, partitions)
   1002         return list(_load_from_socket(port, mappedRDD._jrdd_deserializer))
   1003 

C:\spark\python\lib\py4j-0.10.6-src.zip\py4j\java_gateway.py in __call__(self, *args)
   1158         answer = self.gateway_client.send_command(command)
   1159         return_value = get_return_value(
-> 1160             answer, self.gateway_client, self.target_id, self.name)
   1161 
   1162         for temp_arg in temp_args:

C:\spark\python\pyspark\sql\utils.py in deco(*a, **kw)
     61     def deco(*a, **kw):
     62         try:
---> 63             return f(*a, **kw)
     64         except py4j.protocol.Py4JJavaError as e:
     65             s = e.java_exception.toString()

C:\spark\python\lib\py4j-0.10.6-src.zip\py4j\protocol.py in get_return_value(answer, gateway_client, target_id, name)
    318                 raise Py4JJavaError(
    319                     "An error occurred while calling {0}{1}{2}.\n".
--> 320                     format(target_id, ".", name), value)
    321             else:
    322                 raise Py4JError(

Py4JJavaError: An error occurred while calling z:org.apache.spark.api.python.PythonRDD.runJob.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 0.0 failed 1 times, most recent failure: Lost task 0.0 in stage 0.0 (TID 0, localhost, executor driver): org.apache.spark.api.python.PythonException: Traceback (most recent call last):
  File "C:\spark\python\pyspark\rdd.py", line 1354, in takeUpToNumLeft
    yield next(iterator)
StopIteration

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\spark\python\lib\pyspark.zip\pyspark\worker.py", line 229, in main
  File "C:\spark\python\lib\pyspark.zip\pyspark\worker.py", line 224, in process
  File "C:\spark\python\lib\pyspark.zip\pyspark\serializers.py", line 372, in dump_stream
    vs = list(itertools.islice(iterator, batch))
RuntimeError: generator raised StopIteration

    at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.handlePythonException(PythonRunner.scala:298)
    at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRunner.scala:438)
    at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRunner.scala:421)
    at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.hasNext(PythonRunner.scala:252)
    at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:37)
    at scala.collection.Iterator$class.foreach(Iterator.scala:893)
    at org.apache.spark.InterruptibleIterator.foreach(InterruptibleIterator.scala:28)
    at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:59)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:104)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:48)
    at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:310)
    at org.apache.spark.InterruptibleIterator.to(InterruptibleIterator.scala:28)
    at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:302)
    at org.apache.spark.InterruptibleIterator.toBuffer(InterruptibleIterator.scala:28)
    at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:289)
    at org.apache.spark.InterruptibleIterator.toArray(InterruptibleIterator.scala:28)
    at org.apache.spark.api.python.PythonRDD$$anonfun$1.apply(PythonRDD.scala:141)
    at org.apache.spark.api.python.PythonRDD$$anonfun$1.apply(PythonRDD.scala:141)
    at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:2067)
    at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:2067)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87)
    at org.apache.spark.scheduler.Task.run(Task.scala:109)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:345)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

Driver stacktrace:
    at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1599)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1587)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1586)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
    at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1586)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:831)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:831)
    at scala.Option.foreach(Option.scala:257)
    at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:831)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1820)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1769)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1758)
    at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
    at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:642)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:2027)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:2048)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:2067)
    at org.apache.spark.api.python.PythonRDD$.runJob(PythonRDD.scala:141)
    at org.apache.spark.api.python.PythonRDD.runJob(PythonRDD.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
    at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
    at py4j.Gateway.invoke(Gateway.java:282)
    at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
    at py4j.commands.CallCommand.execute(CallCommand.java:79)
    at py4j.GatewayConnection.run(GatewayConnection.java:214)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.spark.api.python.PythonException: Traceback (most recent call last):
  File "C:\spark\python\pyspark\rdd.py", line 1354, in takeUpToNumLeft
    yield next(iterator)
StopIteration

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\spark\python\lib\pyspark.zip\pyspark\worker.py", line 229, in main
  File "C:\spark\python\lib\pyspark.zip\pyspark\worker.py", line 224, in process
  File "C:\spark\python\lib\pyspark.zip\pyspark\serializers.py", line 372, in dump_stream
    vs = list(itertools.islice(iterator, batch))
RuntimeError: generator raised StopIteration

    at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.handlePythonException(PythonRunner.scala:298)
    at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRunner.scala:438)
    at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRunner.scala:421)
    at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.hasNext(PythonRunner.scala:252)
    at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:37)
    at scala.collection.Iterator$class.foreach(Iterator.scala:893)
    at org.apache.spark.InterruptibleIterator.foreach(InterruptibleIterator.scala:28)
    at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:59)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:104)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:48)
    at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:310)
    at org.apache.spark.InterruptibleIterator.to(InterruptibleIterator.scala:28)
    at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:302)
    at org.apache.spark.InterruptibleIterator.toBuffer(InterruptibleIterator.scala:28)
    at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:289)
    at org.apache.spark.InterruptibleIterator.toArray(InterruptibleIterator.scala:28)
    at org.apache.spark.api.python.PythonRDD$$anonfun$1.apply(PythonRDD.scala:141)
    at org.apache.spark.api.python.PythonRDD$$anonfun$1.apply(PythonRDD.scala:141)
    at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:2067)
    at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:2067)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87)
    at org.apache.spark.scheduler.Task.run(Task.scala:109)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:345)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    ... 1 more

1 Ответ

1 голос
/ 04 мая 2020

Возможно, вы захотите сделать:

simple_data = sc.parallelize([[1, "Alice", 50]]).toDF()
simple_data.count()
simple_data.first()
simple_data.show()

Обратите внимание на изменение внутри parallelize.

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