各位大神，我是hadoop新手，在自己电脑安装好hadoop后，运行wordcount报错，报错已困扰两天，希望有大神可以帮解决。
报错日志如下：
[hadoop@hadoop0 mapreduce]$ hadoop jar hadoop-mapreduce-examples-2.7.1.jar wordcount /input /output
17/04/14 13:49:46 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
17/04/14 13:49:48 INFO client.RMProxy: Connecting to ResourceManager at hadoop0/192.168.79.172:8032
17/04/14 13:49:50 INFO input.FileInputFormat: Total input paths to process : 2
17/04/14 13:49:50 INFO mapreduce.JobSubmitter: number of splits:2
17/04/14 13:49:50 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1492077890345_0003
17/04/14 13:49:51 INFO impl.YarnClientImpl: Submitted application application_1492077890345_0003
17/04/14 13:49:51 INFO mapreduce.Job: The url to track the job: http://hadoop0:8088/proxy/application_1492077890345_0003/
17/04/14 13:49:51 INFO mapreduce.Job: Running job: job_1492077890345_0003
17/04/14 13:50:12 INFO mapreduce.Job: Job job_1492077890345_0003 running in uber mode : false
17/04/14 13:50:12 INFO mapreduce.Job: map 0% reduce 0%
17/04/14 13:50:12 INFO mapreduce.Job: Job job_1492077890345_0003 failed with state FAILED due to: Application application_1492077890345_0003 failed 2 times due to Error launching appattempt_1492077890345_0003_000002. Got exception: java.net.ConnectException: Call From hadoop0/192.168.79.172 to :54895 failed on connection exception: java.net.ConnectException: 拒绝连接; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
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:423)
at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:792)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:732)
at org.apache.hadoop.ipc.Client.call(Client.java:1480)
at org.apache.hadoop.ipc.Client.call(Client.java:1407)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
at com.sun.proxy.$Proxy83.startContainers(Unknown Source)
at org.apache.hadoop.yarn.api.impl.pb.client.ContainerManagementProtocolPBClientImpl.startContainers(ContainerManagementProtocolPBClientImpl.java:96)
at org.apache.hadoop.yarn.server.resourcemanager.amlauncher.AMLauncher.launch(AMLauncher.java:119)
at org.apache.hadoop.yarn.server.resourcemanager.amlauncher.AMLauncher.run(AMLauncher.java:254)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.ConnectException: 拒绝连接
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:495)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:609)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:707)
at org.apache.hadoop.ipc.Client$Connection.access$2800(Client.java:370)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1529)
at org.apache.hadoop.ipc.Client.call(Client.java:1446)
... 9 more
. Failing the application.
17/04/14 13:50:12 INFO mapreduce.Job: Counters: 0
metrics文件内容如下：
另外，在报错日志中发下这么句话Call From hadoop0/192.168.79.172 to :54895 failed ，为什么54895只有端口前面没有IP，是不是环境没有配置正确？
