PySpark — невозможно выполнить какие-либо операции с результатами действия UDF groupby

#python #pandas #apache-spark #pyspark

#python #pandas #apache-spark #pyspark

Вопрос:

Я создал приложение spark, в котором я использовал функцию pandas_udf, которая выдает фреймы данных pandas для каждой группы. Это действие выполняется, и после этого этапа я напечатал несколько записей из результата, и все выглядит нормально.

Код, как показано ниже:

 @pandas_udf(df.schema, PandasUDFType.GROUPED_MAP)
def forecast(ts):
    ##Some Time Series Forecasting Operation goes here and returns forecast of next 7 days
    ##as DataFrame as below
    return pd.DataFrame({'date_key':forcasted_dates,'keyword':key,'hit_numbers':predictions})
 

Вызвал указанную выше функцию следующим образом:

 res = df.groupby('keyword').apply(forecast)
 

Напечатано несколько строк результата следующим образом:

 res.show(5)
 ------------------- ------- ----------- 
|           date_key|keyword|hit_numbers|
 ------------------- ------- ----------- 
|2020-10-01 00:00:00|alquran|        158|
|2020-10-02 00:00:00|alquran|        149|
|2020-10-03 00:00:00|alquran|         81|
|2020-10-04 00:00:00|alquran|         94|
|2020-10-05 00:00:00|alquran|        150|
 ------------------- ------- ----------- 
only showing top 5 rows
 

Но когда я пытаюсь выполнить любую другую операцию, например, подсчитать отдельные значения столбца или преобразовать результат (фрейм данных PySpark) в фрейм данных Pandas, он выдает ошибку, как показано ниже:

 ---------------------------------------------------------------------------
Py4JJavaError                             Traceback (most recent call last)
<ipython-input-46-353422df5245> in <module>
----> 1 res.select('keyword').distinct().count()

/usr/lib/spark/python/pyspark/sql/dataframe.py in count(self)
    522         2
    523         """
--> 524         return int(self._jdf.count())
    525 
    526     @ignore_unicode_prefix

/usr/lib/spark/python/lib/py4j-0.10.7-src.zip/py4j/java_gateway.py in __call__(self, *args)
   1255         answer = self.gateway_client.send_command(command)
   1256         return_value = get_return_value(
-> 1257             answer, self.gateway_client, self.target_id, self.name)
   1258 
   1259         for temp_arg in temp_args:

/usr/lib/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()

/usr/lib/spark/python/lib/py4j-0.10.7-src.zip/py4j/protocol.py in get_return_value(answer, gateway_client, target_id, name)
    326                 raise Py4JJavaError(
    327                     "An error occurred while calling {0}{1}{2}.n".
--> 328                     format(target_id, ".", name), value)
    329             else:
    330                 raise Py4JError(

Py4JJavaError: An error occurred while calling o374.count.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 112 in stage 29.0 failed 4 times, most recent failure: Lost task 112.3 in stage 29.0 (TID 1846, ashwanth-pi-scaling-w-1.c.toped-ds-sandbox.internal, executor 111): org.apache.spark.api.python.PythonException: Traceback (most recent call last):
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/worker.py", line 377, in main
    process()
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/worker.py", line 372, in process
    serializer.dump_stream(func(split_index, iterator), outfile)
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/serializers.py", line 290, in dump_stream
    for series in iterator:
  File "<string>", line 1, in <lambda>
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/worker.py", line 113, in wrapped
    result = f(pd.concat(value_series, axis=1))
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/util.py", line 99, in wrapper
    return f(*args, **kwargs)
  File "<ipython-input-32-6e45198643a7>", line 17, in forecast
  File "/opt/conda/anaconda/lib/python3.6/site-packages/statsmodels/tsa/arima/model.py", line 345, in fit
    cov_type=cov_type, cov_kwds=cov_kwds, **method_kwargs)
  File "/opt/conda/anaconda/lib/python3.6/site-packages/statsmodels/tsa/statespace/mlemodel.py", line 643, in fit
    start_params = self.start_params
  File "/opt/conda/anaconda/lib/python3.6/site-packages/statsmodels/tsa/statespace/sarimax.py", line 956, in start_params
    warning_description='ARMA and trend')
  File "/opt/conda/anaconda/lib/python3.6/site-packages/statsmodels/tsa/statespace/sarimax.py", line 843, in _conditional_sum_squares
    Y = endog[r:]
IndexError: too many indices for array: array is 0-dimensional, but 1 were indexed

    at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.handlePythonException(PythonRunner.scala:456)
    at org.apache.spark.sql.execution.python.ArrowPythonRunner$anon$1.read(ArrowPythonRunner.scala:172)
    at org.apache.spark.sql.execution.python.ArrowPythonRunner$anon$1.read(ArrowPythonRunner.scala:122)
    at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.hasNext(PythonRunner.scala:410)
    at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:37)
    at scala.collection.Iterator$anon$12.hasNext(Iterator.scala:440)
    at scala.collection.Iterator$anon$11.hasNext(Iterator.scala:409)
    at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage3.agg_doAggregateWithKeys_0$(Unknown Source)
    at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage3.processNext(Unknown Source)
    at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43)
    at org.apache.spark.sql.execution.WholeStageCodegenExec$anonfun$13$anon$1.hasNext(WholeStageCodegenExec.scala:636)
    at scala.collection.Iterator$anon$11.hasNext(Iterator.scala:409)
    at org.apache.spark.shuffle.sort.BypassMergeSortShuffleWriter.write(BypassMergeSortShuffleWriter.java:127)
    at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:99)
    at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:55)
    at org.apache.spark.scheduler.Task.run(Task.scala:123)
    at org.apache.spark.executor.Executor$TaskRunner$anonfun$10.apply(Executor.scala:408)
    at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1360)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:414)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$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$failJobAndIndependentStages(DAGScheduler.scala:1926)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$abortStage$1.apply(DAGScheduler.scala:1914)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$abortStage$1.apply(DAGScheduler.scala:1913)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
    at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1913)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:948)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:948)
    at scala.Option.foreach(Option.scala:257)
    at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:948)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:2147)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:2096)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:2085)
    at org.apache.spark.util.EventLoop$anon$1.run(EventLoop.scala:49)
    at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:759)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:2061)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:2082)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:2101)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:2126)
    at org.apache.spark.rdd.RDD$anonfun$collect$1.apply(RDD.scala:990)
    at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)
    at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:112)
    at org.apache.spark.rdd.RDD.withScope(RDD.scala:385)
    at org.apache.spark.rdd.RDD.collect(RDD.scala:989)
    at org.apache.spark.sql.execution.SparkPlan.executeCollect(SparkPlan.scala:299)
    at org.apache.spark.sql.Dataset$anonfun$count$1.apply(Dataset.scala:2836)
    at org.apache.spark.sql.Dataset$anonfun$count$1.apply(Dataset.scala:2835)
    at org.apache.spark.sql.Dataset$anonfun$52.apply(Dataset.scala:3370)
    at org.apache.spark.sql.execution.SQLExecution$anonfun$withNewExecutionId$1.apply(SQLExecution.scala:80)
    at org.apache.spark.sql.execution.SQLExecution$.withSQLConfPropagated(SQLExecution.scala:127)
    at org.apache.spark.sql.execution.SQLExecution$.withNewExecutionId(SQLExecution.scala:75)
    at org.apache.spark.sql.Dataset.org$apache$spark$sql$Dataset$withAction(Dataset.scala:3369)
    at org.apache.spark.sql.Dataset.count(Dataset.scala:2835)
    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:238)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.spark.api.python.PythonException: Traceback (most recent call last):
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/worker.py", line 377, in main
    process()
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/worker.py", line 372, in process
    serializer.dump_stream(func(split_index, iterator), outfile)
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/serializers.py", line 290, in dump_stream
    for series in iterator:
  File "<string>", line 1, in <lambda>
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/worker.py", line 113, in wrapped
    result = f(pd.concat(value_series, axis=1))
  File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/util.py", line 99, in wrapper
    return f(*args, **kwargs)
  File "<ipython-input-32-6e45198643a7>", line 17, in forecast
  File "/opt/conda/anaconda/lib/python3.6/site-packages/statsmodels/tsa/arima/model.py", line 345, in fit
    cov_type=cov_type, cov_kwds=cov_kwds, **method_kwargs)
  File "/opt/conda/anaconda/lib/python3.6/site-packages/statsmodels/tsa/statespace/mlemodel.py", line 643, in fit
    start_params = self.start_params
  File "/opt/conda/anaconda/lib/python3.6/site-packages/statsmodels/tsa/statespace/sarimax.py", line 956, in start_params
    warning_description='ARMA and trend')
  File "/opt/conda/anaconda/lib/python3.6/site-packages/statsmodels/tsa/statespace/sarimax.py", line 843, in _conditional_sum_squares
    Y = endog[r:]
IndexError: too many indices for array: array is 0-dimensional, but 1 were indexed

    at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.handlePythonException(PythonRunner.scala:456)
    at org.apache.spark.sql.execution.python.ArrowPythonRunner$anon$1.read(ArrowPythonRunner.scala:172)
    at org.apache.spark.sql.execution.python.ArrowPythonRunner$anon$1.read(ArrowPythonRunner.scala:122)
    at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.hasNext(PythonRunner.scala:410)
    at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:37)
    at scala.collection.Iterator$anon$12.hasNext(Iterator.scala:440)
    at scala.collection.Iterator$anon$11.hasNext(Iterator.scala:409)
    at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage3.agg_doAggregateWithKeys_0$(Unknown Source)
    at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage3.processNext(Unknown Source)
    at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43)
    at org.apache.spark.sql.execution.WholeStageCodegenExec$anonfun$13$anon$1.hasNext(WholeStageCodegenExec.scala:636)
    at scala.collection.Iterator$anon$11.hasNext(Iterator.scala:409)
    at org.apache.spark.shuffle.sort.BypassMergeSortShuffleWriter.write(BypassMergeSortShuffleWriter.java:127)
    at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:99)
    at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:55)
    at org.apache.spark.scheduler.Task.run(Task.scala:123)
    at org.apache.spark.executor.Executor$TaskRunner$anonfun$10.apply(Executor.scala:408)
    at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1360)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:414)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    ... 1 more
 

В чем может быть возможная проблема здесь?

Комментарии:

1. Это явно исключение python IndexError

2. Хм… Но в чем проблема? Когда я запускаю меньший набор данных, не сталкиваюсь с той же проблемой, что и упоминалось.

3. возможно, проверьте значение null

4. В качестве альтернативы попробуйте следующее: from pyspark.sql.functions import countDistinct df.select(countDistinct("keyword")).show()