【发布时间】:2017-12-18 13:12:10
【问题描述】:
我刚刚参加了 PySpark 培训课程,并且正在编译示例代码行的脚本(这解释了为什么代码块什么都不做)。每次我运行这段代码时,我都会收到一次或两次此错误。抛出它的线在运行之间改变。我尝试设置spark.executor.memory 和spark.executor.heartbeatInterval,但错误仍然存在。我还尝试将.cache() 放在各行的末尾,没有任何变化。
错误:
16/09/21 10:29:32 ERROR Utils: Uncaught exception in thread stdout writer for python
java.net.SocketException: Socket is closed
at java.net.Socket.shutdownOutput(Socket.java:1551)
at org.apache.spark.api.python.PythonRunner$WriterThread$$anonfun$run$3$$anonfun$apply$4.apply$mcV$sp(PythonRDD.scala:344)
at org.apache.spark.api.python.PythonRunner$WriterThread$$anonfun$run$3$$anonfun$apply$4.apply(PythonRDD.scala:344)
at org.apache.spark.api.python.PythonRunner$WriterThread$$anonfun$run$3$$anonfun$apply$4.apply(PythonRDD.scala:344)
at org.apache.spark.util.Utils$.tryLog(Utils.scala:1870)
at org.apache.spark.api.python.PythonRunner$WriterThread$$anonfun$run$3.apply(PythonRDD.scala:344)
at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1857)
at org.apache.spark.api.python.PythonRunner$WriterThread.run(PythonRDD.scala:269)
代码:
from pyspark import SparkConf, SparkContext
def parseLine(line):
fields = line.split(',')
return (int(fields[0]), float(fields[2]))
def parseGraphs(line):
fields = line.split()
return (fields[0]), [int(n) for n in fields[1:]]
# putting the [*] after local makes it run one executor on each core of your local PC
conf = SparkConf().setMaster("local[*]").setAppName("MyProcessName")
sc = SparkContext(conf = conf)
# parse the raw data and map it to an rdd.
# each item in this rdd is a tuple
# two methods to get the exact same data:
########## All of these methods can use lambda or full methods in the same way ##########
# read in a text file
customerOrdersLines = sc.textFile("file:///SparkCourse/customer-orders.csv")
customerOrdersRdd = customerOrdersLines.map(parseLine)
customerOrdersRdd = customerOrdersLines.map(lambda l: (int(l.split(',')[0]), float(l.split(',')[2])))
print customerOrdersRdd.take(1)
# countByValue groups identical values and counts them
salesByCustomer = customerOrdersRdd.map(lambda sale: sale[0]).countByValue()
print salesByCustomer.items()[0]
# use flatMap to cut everything up by whitespace
bookText = sc.textFile("file:///SparkCourse/Book.txt")
bookRdd = bookText.flatMap(lambda l: l.split())
print bookRdd.take(1)
# create key/value pairs that will allow for more complex uses
names = sc.textFile("file:///SparkCourse/marvel-names.txt")
namesRdd = names.map(lambda line: (int(line.split('\"')[0]), line.split('\"')[1].encode("utf8")))
print namesRdd.take(1)
graphs = sc.textFile("file:///SparkCourse/marvel-graph.txt")
graphsRdd = graphs.map(parseGraphs)
print graphsRdd.take(1)
# this will append "extra text" to each name.
# this is faster than a normal map because it doesn't give you access to the keys
extendedNamesRdd = namesRdd.mapValues(lambda heroName: heroName + "extra text")
print extendedNamesRdd.take(1)
# not the best example because the costars is already a list of integers
# but this should return a list, which will update the values
flattenedCostarsRdd = graphsRdd.flatMapValues(lambda costars: costars)
print flattenedCostarsRdd.take(1)
# put the heroes in ascending index order
sortedHeroes = namesRdd.sortByKey()
print sortedHeroes.take(1)
# to sort heroes by alphabetical order, we switch key/value to value/key, then sort
alphabeticalHeroes = namesRdd.map(lambda (key, value): (value, key)).sortByKey()
print alphabeticalHeroes.take(1)
# make sure that "spider" is in the name of the hero
spiderNames = namesRdd.filter(lambda (id, name): "spider" in name.lower())
print spiderNames.take(1)
# reduce by key keeps the key and performs aggregation methods on the values. in this example, taking the sum
combinedGraphsRdd = flattenedCostarsRdd.reduceByKey(lambda value1, value2: value1 + value2)
print combinedGraphsRdd.take(1)
# broadcast: this is accessible from any executor
sentData = sc.broadcast(["this can be accessed by all executors", "access it using sentData"])
# accumulator: this is synced across all executors
hitCounter = sc.accumulator(0)
【问题讨论】:
-
你能告诉它在哪个步骤返回错误吗?你们有印刷作品吗?
-
您可能混淆了源端口和目标端口。默认连接模式
Any(available) >> Target Port,可能默认端口是80,那么你就无法连接到80端口。我强烈建议您使用 Wireshark 检查客户端和服务器连接。 -
什么是 Spark 版本?您可以启动
pyspark并键入一些命令而不会出现错误吗?是Windows,不是吗?上面的代码是怎么执行的? -
你的机器上安装了python吗?
标签: apache-spark pyspark