异常：在Python中创建Spark会话时，Java网关进程在向驱动程序发送其端口号之前退出

Question

因此，我试图使用以下命令在Python2.7中创建一个Spark会话：

#Initialize SparkSession and SparkContext
from pyspark.sql import SparkSession  
from pyspark import SparkContext

#Create a Spark Session
SpSession = SparkSession \
    .builder \
    .master("local[2]") \
    .appName("V2 Maestros") \
    .config("spark.executor.memory", "1g") \
    .config("spark.cores.max","2") \
    .config("spark.sql.warehouse.dir", "file:///c:/temp/spark-warehouse")\
    .getOrCreate()

#Get the Spark Context from Spark Session    
SpContext = SpSession.sparkContext

指向python\lib\pyspark.zip\pyspark\java_gateway.py路径时出现以下错误`

Exception: Java gateway process exited before sending the driver its port number

尝试查看java_gateway.py文件，内容如下：

import atexit
import os
import sys
import select
import signal
import shlex
import socket
import platform
from subprocess import Popen, PIPE

if sys.version >= '3':
    xrange = range

from py4j.java_gateway import java_import, JavaGateway, GatewayClient
from py4j.java_collections import ListConverter

from pyspark.serializers import read_int


# patching ListConverter, or it will convert bytearray into Java ArrayList
def can_convert_list(self, obj):
    return isinstance(obj, (list, tuple, xrange))

ListConverter.can_convert = can_convert_list


def launch_gateway():
    if "PYSPARK_GATEWAY_PORT" in os.environ:
        gateway_port = int(os.environ["PYSPARK_GATEWAY_PORT"])
    else:
        SPARK_HOME = os.environ["SPARK_HOME"]
        # Launch the Py4j gateway using Spark's run command so that we pick up the
        # proper classpath and settings from spark-env.sh
        on_windows = platform.system() == "Windows"
        script = "./bin/spark-submit.cmd" if on_windows else "./bin/spark-submit"
        submit_args = os.environ.get("PYSPARK_SUBMIT_ARGS", "pyspark-shell")
        if os.environ.get("SPARK_TESTING"):
            submit_args = ' '.join([
                "--conf spark.ui.enabled=false",
                submit_args
            ])
        command = [os.path.join(SPARK_HOME, script)] + shlex.split(submit_args)

        # Start a socket that will be used by PythonGatewayServer to communicate its port to us
        callback_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        callback_socket.bind(('127.0.0.1', 0))
        callback_socket.listen(1)
        callback_host, callback_port = callback_socket.getsockname()
        env = dict(os.environ)
        env['_PYSPARK_DRIVER_CALLBACK_HOST'] = callback_host
        env['_PYSPARK_DRIVER_CALLBACK_PORT'] = str(callback_port)

        # Launch the Java gateway.
        # We open a pipe to stdin so that the Java gateway can die when the pipe is broken
        if not on_windows:
            # Don't send ctrl-c / SIGINT to the Java gateway:
            def preexec_func():
                signal.signal(signal.SIGINT, signal.SIG_IGN)
            proc = Popen(command, stdin=PIPE, preexec_fn=preexec_func, env=env)
        else:
            # preexec_fn not supported on Windows
            proc = Popen(command, stdin=PIPE, env=env)

        gateway_port = None
        # We use select() here in order to avoid blocking indefinitely if the subprocess dies
        # before connecting
        while gateway_port is None and proc.poll() is None:
            timeout = 1  # (seconds)
            readable, _, _ = select.select([callback_socket], [], [], timeout)
            if callback_socket in readable:
                gateway_connection = callback_socket.accept()[0]
                # Determine which ephemeral port the server started on:
                gateway_port = read_int(gateway_connection.makefile(mode="rb"))
                gateway_connection.close()
                callback_socket.close()
        if gateway_port is None:
            raise Exception("Java gateway process exited before sending the driver its port number")

        # In Windows, ensure the Java child processes do not linger after Python has exited.
        # In UNIX-based systems, the child process can kill itself on broken pipe (i.e. when
        # the parent process' stdin sends an EOF). In Windows, however, this is not possible
        # because java.lang.Process reads directly from the parent process' stdin, contending
        # with any opportunity to read an EOF from the parent. Note that this is only best
        # effort and will not take effect if the python process is violently terminated.
        if on_windows:
            # In Windows, the child process here is "spark-submit.cmd", not the JVM itself
            # (because the UNIX "exec" command is not available). This means we cannot simply
            # call proc.kill(), which kills only the "spark-submit.cmd" process but not the
            # JVMs. Instead, we use "taskkill" with the tree-kill option "/t" to terminate all
            # child processes in the tree (http://technet.microsoft.com/en-us/library/bb491009.aspx)
            def killChild():
                Popen(["cmd", "/c", "taskkill", "/f", "/t", "/pid", str(proc.pid)])
            atexit.register(killChild)

    # Connect to the gateway
    gateway = JavaGateway(GatewayClient(port=gateway_port), auto_convert=True)

    # Import the classes used by PySpark
    java_import(gateway.jvm, "org.apache.spark.SparkConf")
    java_import(gateway.jvm, "org.apache.spark.api.java.*")
    java_import(gateway.jvm, "org.apache.spark.api.python.*")
    java_import(gateway.jvm, "org.apache.spark.ml.python.*")
    java_import(gateway.jvm, "org.apache.spark.mllib.api.python.*")
    # TODO(davies): move into sql
    java_import(gateway.jvm, "org.apache.spark.sql.*")
    java_import(gateway.jvm, "org.apache.spark.sql.hive.*")
    java_import(gateway.jvm, "scala.Tuple2")

    return gateway

我对Spark和Pyspark很陌生，因此无法在这里调试这个问题。我还试着看了一些其他的建议： Spark + Python - Java gateway process exited before sending the driver its port number? 和 Pyspark: Exception: Java gateway process exited before sending the driver its port number

但至今无法解决。请帮忙！

以下是spark环境的外观：

# This script loads spark-env.sh if it exists, and ensures it is only loaded once.
# spark-env.sh is loaded from SPARK_CONF_DIR if set, or within the current directory's
# conf/ subdirectory.

# Figure out where Spark is installed
if [ -z "${SPARK_HOME}" ]; then
  export SPARK_HOME="$(cd "`dirname "$0"`"/..; pwd)"
fi

if [ -z "$SPARK_ENV_LOADED" ]; then
  export SPARK_ENV_LOADED=1

  # Returns the parent of the directory this script lives in.
  parent_dir="${SPARK_HOME}"

  user_conf_dir="${SPARK_CONF_DIR:-"$parent_dir"/conf}"

  if [ -f "${user_conf_dir}/spark-env.sh" ]; then
    # Promote all variable declarations to environment (exported) variables
    set -a
    . "${user_conf_dir}/spark-env.sh"
    set +a
  fi
fi

# Setting SPARK_SCALA_VERSION if not already set.

if [ -z "$SPARK_SCALA_VERSION" ]; then

  ASSEMBLY_DIR2="${SPARK_HOME}/assembly/target/scala-2.11"
  ASSEMBLY_DIR1="${SPARK_HOME}/assembly/target/scala-2.10"

  if [[ -d "$ASSEMBLY_DIR2" && -d "$ASSEMBLY_DIR1" ]]; then
    echo -e "Presence of build for both scala versions(SCALA 2.10 and SCALA 2.11) detected." 1>&2
    echo -e 'Either clean one of them or, export SPARK_SCALA_VERSION=2.11 in spark-env.sh.' 1>&2
    exit 1
  fi

  if [ -d "$ASSEMBLY_DIR2" ]; then
    export SPARK_SCALA_VERSION="2.11"
  else
    export SPARK_SCALA_VERSION="2.10"
  fi
fi

下面是如何在Python中设置我的Spark环境：

import os
import sys

# NOTE: Please change the folder paths to your current setup.
#Windows
if sys.platform.startswith('win'):
    #Where you downloaded the resource bundle
    os.chdir("E:/Udemy - Spark/SparkPythonDoBigDataAnalytics-Resources")
    #Where you installed spark.    
    os.environ['SPARK_HOME'] = 'E:/Udemy - Spark/Apache Spark/spark-2.0.0-bin-hadoop2.7'
#other platforms - linux/mac
else:
    os.chdir("/Users/kponnambalam/Dropbox/V2Maestros/Modules/Apache Spark/Python")
    os.environ['SPARK_HOME'] = '/users/kponnambalam/products/spark-2.0.0-bin-hadoop2.7'

os.curdir

# Create a variable for our root path
SPARK_HOME = os.environ['SPARK_HOME']
# Create a variable for our root path
SPARK_HOME = os.environ['SPARK_HOME']

#Add the following paths to the system path. Please check your installation
#to make sure that these zip files actually exist. The names might change
#as versions change.
sys.path.insert(0,os.path.join(SPARK_HOME,"python"))
sys.path.insert(0,os.path.join(SPARK_HOME,"python","lib"))
sys.path.insert(0,os.path.join(SPARK_HOME,"python","lib","pyspark.zip"))
sys.path.insert(0,os.path.join(SPARK_HOME,"python","lib","py4j-0.10.1-src.zip"))

#Initialize SparkSession and SparkContext
from pyspark.sql import SparkSession  
from pyspark import SparkContext

Answer 1

在阅读了许多文章之后，我终于在我的Windows笔记本电脑上实现了Spark。我使用Python，但我相信这也适用于标准分布。

所以，你需要确保你能独立运行Spark。我的假设是您已经安装了有效的python path和Java。对于Java，我在路径中定义了“C:\ ProgramData\Oracle\Java\javapath”，该路径将重定向到我的Java8 bin文件夹。

1. 从https://spark.apache.org/downloads.html下载预构建的Hadoop版本的Spark，并将其解压缩到C:\ Spark-2.2.0-bin-hadoop2.7
2. 创建环境变量SPARK_HOME，稍后pyspark需要它来安装本地SPARK。

3. 转到%SPARK_HOME%\bin并尝试运行pyspark，这是Python SPARK shell。如果你的环境和我的环境一样，你会看到无法找到winutils和hadoop的例子。第二个例外是缺少配置单元：

   pyspark.sql.utils.IllegalArgumentException:u“实例化'org.apache.spark.sql.hive.HiveSessionStateBuilder'时出错：”

4. 然后我找到并简单地跟随https://jaceklaskowski.gitbooks.io/mastering-apache-spark/spark-tips-and-tricks-running-spark-windows.html 具体来说：

5. 下载winutils，将其放到c:\ hadoop\bin。创建HADOOP_HOME env并将%HADOOP_HOME%\bin添加到路径。
6. 为配置单元创建目录，例如c:\tmp\Hive，并在管理模式下的cmd中运行winutils.exe chmod -R 777 C:\tmp\hive。
7. 然后转到%SPARK\u HOME%\bin，确保运行pyspark时看到一个很好的ASCII格式的SPARK徽标： 请注意，需要已经定义sc spark上下文变量。
8. 嗯，我的主要目的是让pyspark在我的IDE中自动完成，这就是SPARK_HOME（第2步）的作用。如果所有设置都正确，则应看到以下行正常工作：

希望这有助于您在本地运行Spark代码。

Answer 2

根据我的“猜测”，这是java版本的问题。也许您安装了两个不同的java版本。另外，看起来您正在使用从某个位置复制和粘贴的代码来设置SPARK_HOME等。。有许多简单的例子如何建立火花。而且看起来你在使用Windows。我建议使用*NIX环境来测试，因为这更容易，例如，您可以使用brew来安装Spark。Windows并不是专门为这个。。。

Answer 3

我也有同样的问题。
幸运的是我找到了原因。

from pyspark.sql import SparkSession
# spark = SparkSession.builder.appName('Check Pyspark').master("local").getOrCreate()
spark = SparkSession.builder.appName('CheckPyspark').master("local").getOrCreate()
print spark.sparkContext.parallelize(range(6), 3).collect()

注意第二行和第三行之间的区别。
如果AppName后面的参数类似于“Check Pyspark”，则会出现错误（异常：Java网关进程…。
AppName后面的参数不能有空格。应该把“Check Pyspark”改成“CheckPyspark”。