我安装了Hadoop 2.9.0，我有4个节点。 namenode和resourcemanager服务正在大师和datanodes和nodemanagers运行在奴隶。现在我想运行一个python MapReduce作业。但约伯不成功！请告诉我该怎么办？
终端中作业运行记录：
hadoop@hadoopmaster:/usr/local/hadoop$ bin/hadoop jar share/hadoop/tools/lib/hadoop-streaming-2.9.0.jar -file mapper.py -mapper mapper.py -file reducer.py -reducer reducer.py -input /user/hadoop/* -output /user/hadoop/output
18/06/17 04:26:28 WARN streaming.StreamJob: -file option is deprecated, please use generic option -files instead.
18/06/17 04:26:28 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
packageJobJar: [mapper.py, /tmp/hadoop-unjar3316382199020742755/] [] /tmp/streamjob4930230269569102931.jar tmpDir=null
18/06/17 04:26:28 INFO client.RMProxy: Connecting to ResourceManager at hadoopmaster/192.168.111.175:8050
18/06/17 04:26:29 INFO client.RMProxy: Connecting to ResourceManager at hadoopmaster/192.168.111.175:8050
18/06/17 04:26:29 WARN hdfs.DataStreamer: Caught exception
java.lang.InterruptedException
at java.lang.Object.wait(Native Method)
at java.lang.Thread.join(Thread.java:1249)
at java.lang.Thread.join(Thread.java:1323)
at org.apache.hadoop.hdfs.DataStreamer.closeResponder(DataStreamer.java:980)
at org.apache.hadoop.hdfs.DataStreamer.endBlock(DataStreamer.java:630)
at org.apache.hadoop.hdfs.DataStreamer.run(DataStreamer.java:807)
18/06/17 04:26:29 WARN hdfs.DataStreamer: Caught exception
java.lang.InterruptedException
at java.lang.Object.wait(Native Method)
at java.lang.Thread.join(Thread.java:1249)
at java.lang.Thread.join(Thread.java:1323)
at org.apache.hadoop.hdfs.DataStreamer.closeResponder(DataStreamer.java:980)
at org.apache.hadoop.hdfs.DataStreamer.endBlock(DataStreamer.java:630)
at org.apache.hadoop.hdfs.DataStreamer.run(DataStreamer.java:807)
18/06/17 04:26:29 INFO mapred.FileInputFormat: Total input files to process : 4
18/06/17 04:26:29 WARN hdfs.DataStreamer: Caught exception
java.lang.InterruptedException
at java.lang.Object.wait(Native Method)
at java.lang.Thread.join(Thread.java:1249)
at java.lang.Thread.join(Thread.java:1323)
at org.apache.hadoop.hdfs.DataStreamer.closeResponder(DataStreamer.java:980)
at org.apache.hadoop.hdfs.DataStreamer.endBlock(DataStreamer.java:630)
at org.apache.hadoop.hdfs.DataStreamer.run(DataStreamer.java:807)
18/06/17 04:26:29 INFO mapreduce.JobSubmitter: number of splits:4
18/06/17 04:26:29 INFO Configuration.deprecation: yarn.resourcemanager.system-metrics-publisher.enabled is deprecated. Instead, use yarn.system-metrics-publisher.enabled
18/06/17 04:26:29 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1529233655437_0004
18/06/17 04:26:30 INFO impl.YarnClientImpl: Submitted application application_1529233655437_0004
18/06/17 04:26:30 INFO mapreduce.Job: The url to track the job: http://hadoopmaster.png.com:8088/proxy/application_1529233655437_0004/
18/06/17 04:26:30 INFO mapreduce.Job: Running job: job_1529233655437_0004
18/06/17 04:45:12 INFO mapreduce.Job: Job job_1529233655437_0004 running in uber mode : false
18/06/17 04:45:12 INFO mapreduce.Job: map 0% reduce 0%
18/06/17 04:45:12 INFO mapreduce.Job: Job job_1529233655437_0004 failed with state FAILED due to: Application application_1529233655437_0004 failed 2 times due to Error launching appattempt_1529233655437_0004_000002. Got exception: org.apache.hadoop.net.ConnectTimeoutException: Call From hadoopmaster.png.com/192.168.111.175 to hadoopslave1.png.com:40569 failed on socket timeout exception: org.apache.hadoop.net.ConnectTimeoutException: 20000 millis timeout while waiting for channel to be ready for connect. ch : java.nio.channels.SocketChannel[connection-pending remote=hadoopslave1.png.com/192.168.111.173:40569]; For more details see: http://wiki.apache.org/hadoop/SocketTimeout
at sun.reflect.GeneratedConstructorAccessor38.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:824)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:774)
at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1497)
at org.apache.hadoop.ipc.Client.call(Client.java:1439)
at org.apache.hadoop.ipc.Client.call(Client.java:1349)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:227)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:116)
at com.sun.proxy.$Proxy82.startContainers(Unknown Source)
at org.apache.hadoop.yarn.api.impl.pb.client.ContainerManagementProtocolPBClientImpl.startContainers(ContainerManagementProtocolPBClientImpl.java:128)
at sun.reflect.GeneratedMethodAccessor14.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:422)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:165)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:157)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:359)
at com.sun.proxy.$Proxy83.startContainers(Unknown Source)
at org.apache.hadoop.yarn.server.resourcemanager.amlauncher.AMLauncher.launch(AMLauncher.java:122)
at org.apache.hadoop.yarn.server.resourcemanager.amlauncher.AMLauncher.run(AMLauncher.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.hadoop.net.ConnectTimeoutException: 20000 millis timeout while waiting for channel to be ready for connect. ch : java.nio.channels.SocketChannel[connection-pending remote=hadoopslave1.png.com/192.168.111.173:40569]
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:534)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:687)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:790)
at org.apache.hadoop.ipc.Client$Connection.access$3500(Client.java:411)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1554)
at org.apache.hadoop.ipc.Client.call(Client.java:1385)
... 19 more
. Failing the application.
18/06/17 04:45:13 INFO mapreduce.Job: Counters: 0
18/06/17 04:45:13 ERROR streaming.StreamJob: Job not successful!
Streaming Command Failed!
好。我找到了问题的原因。实际上，应该解决以下错误：
hadoopmaster.png.com/192.168.111.175到hadoopslave1.png.com:40569套接字超时异常失败
所以刚做了：
sudo ufw allow 40569