Question

我是pyspark的新手，正在尝试使用word_tokenize（）函数。这是我的代码：

import nltk
from nltk import word_tokenize
import pandas as pd

df_pd = df2.select("*").toPandas()
df2.select('text').apply(word_tokenize)
df_pd.show()

我使用JDK 1.8，Python 3.7，Spark 2.4.3。

能告诉我我做错了什么吗？如何解决？该代码下面的代码运行良好，没有任何错误。

我收到这样的消息：

Py4JJavaError: An error occurred while calling o106.collectToPython.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 14.0 failed 1 times, most recent failure: Lost task 0.0 in stage 14.0 (TID 330, localhost, executor driver): java.lang.OutOfMemoryError: Java heap space
    at java.util.Arrays.copyOf(Arrays.java:3236)
    at java.io.ByteArrayOutputStream.grow(ByteArrayOutputStream.java:118)
    at java.io.ByteArrayOutputStream.ensureCapacity(ByteArrayOutputStream.java:93)
    at java.io.ByteArrayOutputStream.write(ByteArrayOutputStream.java:153)
    at org.apache.spark.util.ByteBufferOutputStream.write(ByteBufferOutputStream.scala:41)
    at java.io.ObjectOutputStream$BlockDataOutputStream.write(ObjectOutputStream.java:1853)
    at java.io.ObjectOutputStream.write(ObjectOutputStream.java:709)
    at org.apache.spark.util.Utils$.writeByteBuffer(Utils.scala:260)
    at org.apache.spark.scheduler.DirectTaskResult$$anonfun$writeExternal$1.apply$mcV$sp(TaskResult.scala:50)
    at org.apache.spark.scheduler.DirectTaskResult$$anonfun$writeExternal$1.apply(TaskResult.scala:48)
    at org.apache.spark.scheduler.DirectTaskResult$$anonfun$writeExternal$1.apply(TaskResult.scala:48)
    at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1326)
    at org.apache.spark.scheduler.DirectTaskResult.writeExternal(TaskResult.scala:48)
    at java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1459)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1430)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
    at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
    at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:517)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)


 and more....

Answer 1

toPandas已针对较小的数据集进行了优化。如建议的那样，可能是由于内存不足，导致出现错误。

尝试限制您的数据集大小： df_pd = df2.limit（10）.select（“ *”）。toPandas（）

应用您的函数，然后运行.head（10）将您的问题消除为内存错误。

如何在使用.toPandas（）函数时修复Py4JJavaError？

1 个答案: