问题
I'm trying out some pyspark related experiments on jupyter notebook attached to an AWS EMR instance. I've a spark dataframe which reads data from s3, and then filters out some stuffs. Printing the schema using df1.printSchema() outputs like this:
root
|-- idvalue: string (nullable = true)
|-- locationaccuracyhorizontal: float (nullable = true)
|-- hour: integer (nullable = true)
|-- day: integer (nullable = true)
|-- date: date (nullable = true)
|-- is_weekend: boolean (nullable = true)
|-- locationlatrad: float (nullable = true)
|-- locationlonrad: float (nullable = true)
|-- epochtimestamp: integer (nullable = true)
I'm trying to apply a pandas_udf on this dataframe (examples here). My udf being:
@pandas_udf(df1.schema, PandasUDFType.GROUPED_MAP)
def normalize(pdf):
hour = pdf.hour
return pdf.assign(hour=(hour - hour.mean()) / hour.std())
The invocation goes like this:
df2 = df1.groupBy('idvalue') \
.apply(normalize).show()
Unfortunately this is throwing error, saying:
An error occurred while calling o522.showString.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 11.0 failed 4 times, most recent failure: Lost task 0.3 in stage 11.0 (TID 31, x.x.x.x, executor 7): org.apache.spark.api.python.PythonException: Traceback (most recent call last):
File "/usr/local/lib64/python3.6/site-packages/pandas/core/indexes/accessors.py", line 256, in _make_accessor
return maybe_to_datetimelike(data)
File "/usr/local/lib64/python3.6/site-packages/pandas/core/indexes/accessors.py", line 82, in maybe_to_datetimelike
"datetimelike index".format(type(data)))
TypeError: cannot convert an object of type <class 'pandas.core.series.Series'> to a datetimelike index
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/mnt1/yarn/usercache/livy/appcache/application_1555045880196_0210/container_1555045880196_0210_01_000013/pyspark.zip/pyspark/worker.py", line 372, in main
process()
File "/mnt1/yarn/usercache/livy/appcache/application_1555045880196_0210/container_1555045880196_0210_01_000013/pyspark.zip/pyspark/worker.py", line 367, in process
serializer.dump_stream(func(split_index, iterator), outfile)
File "/mnt1/yarn/usercache/livy/appcache/application_1555045880196_0210/container_1555045880196_0210_01_000013/pyspark.zip/pyspark/serializers.py", line 283, in dump_stream
for series in iterator:
File "/mnt1/yarn/usercache/livy/appcache/application_1555045880196_0210/container_1555045880196_0210_01_000013/pyspark.zip/pyspark/serializers.py", line 301, in load_stream
yield [self.arrow_to_pandas(c) for c in pa.Table.from_batches([batch]).itercolumns()]
File "/mnt1/yarn/usercache/livy/appcache/application_1555045880196_0210/container_1555045880196_0210_01_000013/pyspark.zip/pyspark/serializers.py", line 301, in <listcomp>
yield [self.arrow_to_pandas(c) for c in pa.Table.from_batches([batch]).itercolumns()]
File "/mnt1/yarn/usercache/livy/appcache/application_1555045880196_0210/container_1555045880196_0210_01_000013/pyspark.zip/pyspark/serializers.py", line 271, in arrow_to_pandas
s = _check_series_convert_date(s, from_arrow_type(arrow_column.type))
File "/mnt1/yarn/usercache/livy/appcache/application_1555045880196_0210/container_1555045880196_0210_01_000013/pyspark.zip/pyspark/sql/types.py", line 1692, in _check_series_convert_date
return series.dt.date
File "/usr/local/lib64/python3.6/site-packages/pandas/core/generic.py", line 3610, in __getattr__
return object.__getattribute__(self, name)
File "/usr/local/lib64/python3.6/site-packages/pandas/core/accessor.py", line 54, in __get__
return self.construct_accessor(instance)
File "/usr/local/lib64/python3.6/site-packages/pandas/core/indexes/accessors.py", line 258, in _make_accessor
raise AttributeError("Can only use .dt accessor with "
AttributeError: Can only use .dt accessor with datetimelike values
at org.apache.spark.api.python.BasePythonRunner$ReaderIterator.handlePythonException(PythonRunner.scala:452)
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:406)
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.processNext(Unknown Source)
at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43)
at org.apache.spark.sql.execution.WholeStageCodegenExec$$anonfun$11$$anon$1.hasNext(WholeStageCodegenExec.scala:619)
at org.apache.spark.sql.execution.SparkPlan$$anonfun$2.apply(SparkPlan.scala:255)
at org.apache.spark.sql.execution.SparkPlan$$anonfun$2.apply(SparkPlan.scala:247)
at org.apache.spark.rdd.RDD$$anonfun$mapPartitionsInternal$1$$anonfun$apply$24.apply(RDD.scala:836)
at org.apache.spark.rdd.RDD$$anonfun$mapPartitionsInternal$1$$anonfun$apply$24.apply(RDD.scala:836)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:52)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:52)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:90)
at org.apache.spark.scheduler.Task.run(Task.scala:121)
at org.apache.spark.executor.Executor$TaskRunner$$anonfun$10.apply(Executor.scala:402)
at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1360)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:408)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Driver stacktrace:
at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:2039)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:2027)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:2026)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:2026)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:966)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:966)
at scala.Option.foreach(Option.scala:257)
at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:966)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:2260)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:2209)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:2198)
at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:49)
at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:777)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2061)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2082)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2101)
at org.apache.spark.sql.execution.SparkPlan.executeTake(SparkPlan.scala:365)
at org.apache.spark.sql.execution.CollectLimitExec.executeCollect(limit.scala:38)
at org.apache.spark.sql.Dataset.org$apache$spark$sql$Dataset$$collectFromPlan(Dataset.scala:3384)
at org.apache.spark.sql.Dataset$$anonfun$head$1.apply(Dataset.scala:2545)
at org.apache.spark.sql.Dataset$$anonfun$head$1.apply(Dataset.scala:2545)
at org.apache.spark.sql.Dataset$$anonfun$53.apply(Dataset.scala:3365)
at org.apache.spark.sql.execution.SQLExecution$$anonfun$withNewExecutionId$1.apply(SQLExecution.scala:78)
at org.apache.spark.sql.execution.SQLExecution$.withSQLConfPropagated(SQLExecution.scala:125)
at org.apache.spark.sql.execution.SQLExecution$.withNewExecutionId(SQLExecution.scala:73)
at org.apache.spark.sql.Dataset.withAction(Dataset.scala:3364)
at org.apache.spark.sql.Dataset.head(Dataset.scala:2545)
at org.apache.spark.sql.Dataset.take(Dataset.scala:2759)
at org.apache.spark.sql.Dataset.getRows(Dataset.scala:255)
at org.apache.spark.sql.Dataset.showString(Dataset.scala:292)
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/local/lib64/python3.6/site-packages/pandas/core/indexes/accessors.py", line 256, in _make_accessor
return maybe_to_datetimelike(data)
File "/usr/local/lib64/python3.6/site-packages/pandas/core/indexes/accessors.py", line 82, in maybe_to_datetimelike
"datetimelike index".format(type(data)))
TypeError: cannot convert an object of type <class 'pandas.core.series.Series'> to a datetimelike index
I'm not understanding why it's throwing datetime related error. None of the operations that I'm doing is related to that. Any help is appreciated.
回答1:
I think pandas_udf doesn't support all the spark types yet, and it seems like it's having trouble with your date_time column.
One issue with any udf is that all the data has to be materialized for your udf, even if the udf ignores the values, which can result in issues like this, or at minimum performance degradation. All else being equal, you should try to reduce the number of columns you pass into your udf. For example, by adding a select before your groupby.
df2 = df1.select('idvalue', 'hour').groupBy('idvalue').apply(normalize).show()
来源：https://stackoverflow.com/questions/56053572/cant-apply-a-pandas-udf-in-pyspark