提交Python程序到Spark集群中出现的问题

在尝试将Python程序提交到Spark集群中，使用官方的例子却报错了
使用如下的代码提交：
# Run a Python application on a Spark standalone cluster./bin/spark-submit \  --master  spark://192.168.1.102:7077 \  examples/src/main/python/pi.py \  10报如下的错误：
16/09/22 16:00:56 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
16/09/22 16:00:59 ERROR SparkContext: Error initializing SparkContext.
java.lang.IllegalArgumentException: java.net.UnknownHostException: namenode
    at org.apache.hadoop.security.SecurityUtil.buildTokenService(SecurityUtil.java:374)
    at org.apache.hadoop.hdfs.NameNodeProxies.createNonHAProxy(NameNodeProxies.java:312)
    at org.apache.hadoop.hdfs.NameNodeProxies.createProxy(NameNodeProxies.java:178)
    at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:665)
    at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:601)
    at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:148)
    at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2596)
    at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:91)
    at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2630)
    at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2612)
    at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:370)
    at org.apache.spark.util.Utils$.getHadoopFileSystem(Utils.scala:1686)
    at org.apache.spark.scheduler.EventLoggingListener.<init>(EventLoggingListener.scala:66)
    at org.apache.spark.SparkContext.<init>(SparkContext.scala:547)
    at org.apache.spark.api.java.JavaSparkContext.<init>(JavaSparkContext.scala:59)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:234)
    at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:381)
    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:209)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.UnknownHostException: namenode
    ... 26 more
Traceback (most recent call last):
  File "/usr/app/dev/spark-1.6.2-bin-hadoop2.6/examples/src/main/python/pi.py", line 30, in <module>
    sc = SparkContext(appName="PythonPi")
  File "/usr/app/dev/spark-1.6.2-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/context.py", line 115, in __init__
  File "/usr/app/dev/spark-1.6.2-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/context.py", line 172, in _do_init
  File "/usr/app/dev/spark-1.6.2-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/context.py", line 235, in _initialize_context
  File "/usr/app/dev/spark-1.6.2-bin-hadoop2.6/python/lib/py4j-0.9-src.zip/py4j/java_gateway.py", line 1064, in __call__
  File "/usr/app/dev/spark-1.6.2-bin-hadoop2.6/python/lib/py4j-0.9-src.zip/py4j/protocol.py", line 308, in get_return_value
py4j.protocol.Py4JJavaError: An error occurred while calling None.org.apache.spark.api.java.JavaSparkContext.
: java.lang.IllegalArgumentException: java.net.UnknownHostException: namenode
    at org.apache.hadoop.security.SecurityUtil.buildTokenService(SecurityUtil.java:374)
    at org.apache.hadoop.hdfs.NameNodeProxies.createNonHAProxy(NameNodeProxies.java:312)
    at org.apache.hadoop.hdfs.NameNodeProxies.createProxy(NameNodeProxies.java:178)
    at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:665)
    at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:601)
    at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:148)
    at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2596)
    at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:91)
    at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2630)
    at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2612)
    at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:370)
    at org.apache.spark.util.Utils$.getHadoopFileSystem(Utils.scala:1686)
    at org.apache.spark.scheduler.EventLoggingListener.<init>(EventLoggingListener.scala:66)
    at org.apache.spark.SparkContext.<init>(SparkContext.scala:547)
    at org.apache.spark.api.java.JavaSparkContext.<init>(JavaSparkContext.scala:59)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:234)
    at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:381)
    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:209)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.UnknownHostException: namenode
    ... 26 more



同时：去掉master选项，那么没有报错，但是，在集群的管理界面上没看到运行的app
请问如何解决呢？