尝试启动 PySpark 时出现空指针异常

Question

我正在使用以下命令启动 pyspark

./bin/pyspark --master yarn --deploy-mode client --executor-memory 5g

然后出现以下错误

15/10/14 17:19:15 INFO spark.SparkContext: SparkContext already stopped.
Traceback (most recent call last):
  File "/opt/spark-1.5.1/python/pyspark/shell.py", line 43, in <module>
    sc = SparkContext(pyFiles=add_files)
  File "/opt/spark-1.5.1/python/pyspark/context.py", line 113, in __init__
    conf, jsc, profiler_cls)
  File "/opt/spark-1.5.1/python/pyspark/context.py", line 178, in _do_init
    self._jvm.PythonAccumulatorParam(host, port))
  File "/opt/spark-1.5.1/python/lib/py4j-0.8.2.1-src.zip/py4j/java_gateway.py", line 701, in __call__
  File "/opt/spark-1.5.1/python/lib/py4j-0.8.2.1-src.zip/py4j/protocol.py", line 300, in get_return_value
py4j.protocol.Py4JJavaError: An error occurred while calling None.org.apache.spark.api.python.PythonAccumulatorParam.
: java.lang.NullPointerException
        at org.apache.spark.api.python.PythonAccumulatorParam.<init>(PythonRDD.scala:825)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
        at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:234)
        at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:379)
        at py4j.Gateway.invoke(Gateway.java:214)
        at py4j.commands.ConstructorCommand.invokeConstructor(ConstructorCommand.java:79)
        at py4j.commands.ConstructorCommand.execute(ConstructorCommand.java:68)
        at py4j.GatewayConnection.run(GatewayConnection.java:207)
        at java.lang.Thread.run(Thread.java:745)

出于某种原因，我也收到了这条消息

 ERROR cluster.YarnClientSchedulerBackend: Yarn application has already exited with state FINISHED!

和

WARN remote.ReliableDeliverySupervisor: Association with remote system [akka.tcp://sparkYarnAM@192.168.1.112:48644] has failed, address is now gated for [5000] ms. Reason: [Disassociated]

可能这就是我停止 SparkContext 的原因。

我正在使用 Spark 1.5.1 和 Hadoop 2.7.1 以及 Yarn 2.7。

有谁知道为什么 Yarn 应用程序在任何事情发生之前就退出了？

有关更多信息，这是我的纱线-site.xml

        <property>
                <name>yarn.nodemanager.resource.memory-mb</name>
                <value>26624</value>
        </property>
        <property>
                <name>yarn.scheduler.minimum-allocation-mb</name>
                <value>1024</value>
        </property>
        <property>
                <name>yarn.scheduler.maximum-allocation-mb</name>
                <value>26624</value>
        </property>
        <property>
                <name>yarn.nodemanager.vmem-pmem-ratio</name>
                <value>2.1</value>
        </property>

这是我的 mapred-site.xml

    <property>
            <name>mapreduce.map.memory.mb</name>
            <value>2048</value>
    </property>
    <property>
            <name>mapreduce.map.java.opts</name>
            <value>-Xmx1640M</value>
            <description>Heap size for map jobs.</description>
    </property>
    <property>
            <name>mapreduce.reduce.memory.mb</name>
            <value>16384</value>
    </property>
    <property>
            <name>mapreduce.reduce.java.opts</name>
            <value>-Xmx13107M</value>
            <description>Heap size for reduce jobs.</description>
    </property>

Answer 1

我可以通过添加

来解决这个问题

spark.yarn.am.memory 5g

到 spark-default.conf 文件。

我认为这是一个与内存相关的问题。

此参数的默认值为 512m

Answer 2

我遇到了一些类似的问题，当我查看端口 8088 上的 Hadoop GUI 并单击我的 PySpark 作业的 ID 列中的应用程序 link 时，我看到以下错误：

Uncaught exception: org.apache…InvalidResourceRequestException Invalid resource request, requested virtual cores < 0, or requested virtual cores > max configured, requestedVirtualCores=8, maxVirtualCores=1

如果我将我的脚本更改为使用 --executor-cores 1 而不是我的默认值 (--executor-cores 8)，那么它就起作用了。现在我只需要让管理员更改一些 Yarn 设置以允许更多内核，例如 yarn.scheduler.maximum-allocation-vcores，请参阅

尝试启动 PySpark 时出现空指针异常

Getting a Null Pointer Exception when I am trying to start PySpark

python

hadoop

apache-spark

pyspark