我正在运行 Pyspark 作业:
spark-submit --master yarn-client --driver-memory 150G --num-executors 8 --executor-cores 4 --executor-memory 150G benchmark_script_1.py hdfs:///tmp/data/sample150k 128 hdfs:///tmp/output/sample150k | tee ~/output/sample150k.log
工作本身非常标准。它只是抓取一些文件并对它们进行计数。:
print(str(datetime.now()) + " - Ingesting files...")
files = sc.wholeTextFiles(inputFileDir, partitions)
fileCount = files.count()
print(str(datetime.now()) + " - " + str(fileCount) + " files ingested")
源文件夹包含约 150'000 个文件。没有复制大约是 35G,有复制大约是 105G。相当沉重但不疯狂。
运行上面的代码会得到以下堆栈跟踪:
15/08/11 15:39:20 WARN TaskSetManager: Lost task 61.3 in stage 0.0 (TID 76, <NODE>): java.io.IOException: Filesystem closed
at org.apache.hadoop.hdfs.DFSClient.checkOpen(DFSClient.java:794)
at org.apache.hadoop.hdfs.DFSInputStream.readWithStrategy(DFSInputStream.java:833)
at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:897)
at java.io.DataInputStream.read(DataInputStream.java:100)
at org.spark-project.guava.io.ByteStreams.copy(ByteStreams.java:207)
at org.spark-project.guava.io.ByteStreams.toByteArray(ByteStreams.java:252)
at org.apache.spark.input.WholeTextFileRecordReader.nextKeyValue(WholeTextFileRecordReader.scala:83)
at org.apache.hadoop.mapreduce.lib.input.CombineFileRecordReader.nextKeyValue(CombineFileRecordReader.java:69)
at org.apache.spark.rdd.NewHadoopRDD$$anon$1.hasNext(NewHadoopRDD.scala:143)
at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:39)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at org.apache.spark.InterruptibleIterator.foreach(InterruptibleIterator.scala:28)
at org.apache.spark.api.python.PythonRDD$.writeIteratorToStream(PythonRDD.scala:405)
at org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply(PythonRDD.scala:243)
at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1617)
at org.apache.spark.api.python.PythonRDD$WriterThread.run(PythonRDD.scala:205)
可以在有问题的执行程序日志中找到更多信息:
15/08/11 12:28:18 ERROR executor.CoarseGrainedExecutorBackend: RECEIVED SIGNAL 15: SIGTERM
15/08/11 12:28:18 ERROR util.Utils: Uncaught exception in thread stdout writer for python
java.lang.OutOfMemoryError: Requested array size exceeds VM limit
at java.lang.StringCoding.encode(StringCoding.java:350)
at java.lang.String.getBytes(String.java:939)
at org.apache.spark.api.python.PythonRDD$.writeUTF(PythonRDD.scala:573)
at org.apache.spark.api.python.PythonRDD$.org$apache$spark$api$python$PythonRDD$$write$1(PythonRDD.scala:395)
at org.apache.spark.api.python.PythonRDD$$anonfun$writeIteratorToStream$1.apply(PythonRDD.scala:405)
at org.apache.spark.api.python.PythonRDD$$anonfun$writeIteratorToStream$1.apply(PythonRDD.scala:405)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at org.apache.spark.InterruptibleIterator.foreach(InterruptibleIterator.scala:28)
at org.apache.spark.api.python.PythonRDD$.writeIteratorToStream(PythonRDD.scala:405)
at org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply(PythonRDD.scala:243)
at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1617)
at org.apache.spark.api.python.PythonRDD$WriterThread.run(PythonRDD.scala:205)
Traceback (most recent call last):
File "/opt/cloudera/parcels/CDH-5.4.2-1.cdh5.4.2.p0.2/jars/spark-assembly-1.3.0-cdh5.4.2-hadoop2.6.0-cdh5.4.2.jar/pyspark/daemon.py", line 162, in manager
File "/opt/cloudera/parcels/CDH-5.4.2-1.cdh5.4.2.p0.2/jars/spark-assembly-1.3.0-cdh5.4.2-hadoop2.6.0-cdh5.4.2.jar/pyspark/daemon.py", line 60, in worker
File "/opt/cloudera/parcels/CDH-5.4.2-1.cdh5.4.2.p0.2/jars/spark-assembly-1.3.0-cdh5.4.2-hadoop2.6.0-cdh5.4.2.jar/pyspark/worker.py", line 126, in main
if read_int(infile) == SpecialLengths.END_OF_STREAM:
File "/opt/cloudera/parcels/CDH-5.4.2-1.cdh5.4.2.p0.2/jars/spark-assembly-1.3.0-cdh5.4.2-hadoop2.6.0-cdh5.4.2.jar/pyspark/serializers.py", line 528, in read_int
15/08/11 12:28:18 ERROR util.SparkUncaughtExceptionHandler: Uncaught exception in thread Thread[stdout writer for python,5,main]
java.lang.OutOfMemoryError: Requested array size exceeds VM limit
at java.lang.StringCoding.encode(StringCoding.java:350)
at java.lang.String.getBytes(String.java:939)
at org.apache.spark.api.python.PythonRDD$.writeUTF(PythonRDD.scala:573)
at org.apache.spark.api.python.PythonRDD$.org$apache$spark$api$python$PythonRDD$$write$1(PythonRDD.scala:395)
at org.apache.spark.api.python.PythonRDD$$anonfun$writeIteratorToStream$1.apply(PythonRDD.scala:405)
at org.apache.spark.api.python.PythonRDD$$anonfun$writeIteratorToStream$1.apply(PythonRDD.scala:405)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at org.apache.spark.InterruptibleIterator.foreach(InterruptibleIterator.scala:28)
at org.apache.spark.api.python.PythonRDD$.writeIteratorToStream(PythonRDD.scala:405)
at org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply(PythonRDD.scala:243)
at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1617)
at org.apache.spark.api.python.PythonRDD$WriterThread.run(PythonRDD.scala:205)
raise EOFError
EOFError
Traceback (most recent call last):
File "/opt/cloudera/parcels/CDH-5.4.2-1.cdh5.4.2.p0.2/jars/spark-assembly-1.3.0-cdh5.4.2-hadoop2.6.0-cdh5.4.2.jar/pyspark/daemon.py", line 162, in manager
File "/opt/cloudera/parcels/CDH-5.4.2-1.cdh5.4.2.p0.2/jars/spark-assembly-1.3.0-cdh5.4.2-hadoop2.6.0-cdh5.4.2.jar/pyspark/daemon.py", line 60, in worker
File "/opt/cloudera/parcels/CDH-5.4.2-1.cdh5.4.2.p0.2/jars/spark-assembly-1.3.0-cdh5.4.2-hadoop2.6.0-cdh5.4.2.jar/pyspark/worker.py", line 126, in main
if read_int(infile) == SpecialLengths.END_OF_STREAM:
File "/opt/cloudera/parcels/CDH-5.4.2-1.cdh5.4.2.p0.2/jars/spark-assembly-1.3.0-cdh5.4.2-hadoop2.6.0-cdh5.4.2.jar/pyspark/serializers.py", line 528, in read_int
15/08/11 12:28:18 ERROR executor.Executor: Exception in task 7.0 in stage 0.0 (TID 5)
java.io.IOException: Filesystem closed
at org.apache.hadoop.hdfs.DFSClient.checkOpen(DFSClient.java:794)
at org.apache.hadoop.hdfs.DFSInputStream.readWithStrategy(DFSInputStream.java:833)
at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:897)
at java.io.DataInputStream.read(DataInputStream.java:100)
at org.spark-project.guava.io.ByteStreams.copy(ByteStreams.java:207)
at org.spark-project.guava.io.ByteStreams.toByteArray(ByteStreams.java:252)
at org.apache.spark.input.WholeTextFileRecordReader.nextKeyValue(WholeTextFileRecordReader.scala:83)
at org.apache.hadoop.mapreduce.lib.input.CombineFileRecordReader.nextKeyValue(CombineFileRecordReader.java:69)
at org.apache.spark.rdd.NewHadoopRDD$$anon$1.hasNext(NewHadoopRDD.scala:143)
at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:39)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at org.apache.spark.InterruptibleIterator.foreach(InterruptibleIterator.scala:28)
at org.apache.spark.api.python.PythonRDD$.writeIteratorToStream(PythonRDD.scala:405)
at org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply(PythonRDD.scala:243)
at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1617)
at org.apache.spark.api.python.PythonRDD$WriterThread.run(PythonRDD.scala:205)
raise EOFError
EOFError
我已经禁用了 HDFS 缓存:
conf.set("fs.hdfs.impl.disable.cache", True)
请注意,在 Scala 中完全相同的脚本根本没有任何问题。
尽管这是一项大型工作,但仍有大量可用内存。任何人都知道问题可能是什么?
更新
为 JVM 分配更多内存。
export set JAVA_OPTS="-Xmx6G -XX:MaxPermSize=2G -XX:+UseCompressedOops"
遗憾的是,没有任何改善。
最佳答案
我在使用 spark-submit 和 Java 时遇到了类似的问题,保存了一个 8GB 的 DataFrame。具有 16 核、300GB RAM 的 Docker 容器。我还没有解决问题,但我遇到了几个可能的解决方法:
从第 77 页开始,Lightbend表明这是 shell 的问题,使用 @transient 或封装在对象中可能是一种解决方法。这似乎不适用于我们的任何一种情况。
DataBricks建议增加 spark.sql.shuffle.partitions
可能有帮助。他们建议将默认的“200”更改为“400”。我在 spark-defaults.conf
中尝试过“800”和“2000”但仍然出现 OOM 错误。
DataBricks还建议调用 DataFrame.repartition(400)
在代码中。或者,增加 partitions
的数量作为调用 sc.wholeTextFiles(inputFileDir, partitions)
的最后一个参数
JAVA_OPTS
来自 StackOverflow 的建议不适用于 -XX:+UseCompressedOops
如果堆大小大于 32GB,则禁用(在 Java 8 中)
编辑
还试过:
-
spark.default.parallelism=1000
(默认为核心数)。仍然是 OOM 错误。 -
dataFrame.repartition(1000)
在代码中。仍然是 OOM 错误。
可能的解决方法
使用中间体
RDD<LabeledPoint>
允许我创建 DataFrame,但 Spark 反射模式不适用于 MLLib(缺少 numClasses 属性)。DataFrame df = sqlContext.createDataFrame(sc.parallelize(List<LabeledPoint>),LabeledPoint.class)
使用中间 JSON 文件允许我创建 DataFrame 以使用 MLLib。
saveAsJson(List<Row>/*generated data*/, filename); DataFrame df = sqlContext.read().json(filename)
关于python - Pyspark java.lang.OutOfMemoryError : Requested array size exceeds VM limit 错误,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31945007/