运行环境：ubuntu
自己生成了个jar包，用hadoop jar xxx.jar ./input ./output，运行成功，可以输出结果，但是最后提示Redirecting to job history server...Client: Retrying connect to server:
具体如下：
16/06/22 21:51:23 INFO mapred.ClientServiceDelegate: Application state is completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job history server
16/06/22 21:51:24 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 0 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:25 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 1 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:26 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 2 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:27 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 3 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:28 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 4 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:29 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 5 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:30 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 6 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:31 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 7 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:32 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 8 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:33 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 9 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:34 INFO mapred.ClientServiceDelegate: Application state is completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job history server
16/06/22 21:51:35 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 0 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:36 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 1 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:37 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 2 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:38 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 3 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:39 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 4 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:40 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 5 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:41 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 6 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:42 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 7 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:43 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 8 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:44 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 9 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:44 INFO mapred.ClientServiceDelegate: Application state is completed. FinalApplicationStatus=SUCCEEDED. Redirecting to job history server
16/06/22 21:51:45 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 0 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:46 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 1 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:47 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 2 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:48 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 3 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:49 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 4 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:50 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 5 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:51 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 6 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:52 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 7 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:53 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 8 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
16/06/22 21:51:54 INFO ipc.Client: Retrying connect to server: backup01/192.168.137.200:10020. Already tried 9 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)
Exception in thread "main" java.io.IOException: java.net.ConnectException: Call From backup01/192.168.137.200 to backup01:10020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
at org.apache.hadoop.mapred.ClientServiceDelegate.invoke(ClientServiceDelegate.java:338)
at org.apache.hadoop.mapred.ClientServiceDelegate.getJobStatus(ClientServiceDelegate.java:423)
at org.apache.hadoop.mapred.YARNRunner.getJobStatus(YARNRunner.java:576)
at org.apache.hadoop.mapreduce.Job$1.run(Job.java:326)
at org.apache.hadoop.mapreduce.Job$1.run(Job.java:323)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1656)
at org.apache.hadoop.mapreduce.Job.updateStatus(Job.java:323)
at org.apache.hadoop.mapreduce.Job.isSuccessful(Job.java:623)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1330)
at org.apache.hadoop.examples.WordCount.main(WordCount.java:87)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.RunJar.run(RunJar.java:221)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)
Caused by: java.net.ConnectException: Call From backup01/192.168.137.200 to backup01:10020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:791)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:731)
at org.apache.hadoop.ipc.Client.call(Client.java:1473)
at org.apache.hadoop.ipc.Client.call(Client.java:1400)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:232)
at com.sun.proxy.$Proxy14.getJobReport(Unknown Source)
at org.apache.hadoop.mapreduce.v2.api.impl.pb.client.MRClientProtocolPBClientImpl.getJobReport(MRClientProtocolPBClientImpl.java:133)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.mapred.ClientServiceDelegate.invoke(ClientServiceDelegate.java:324)
... 17 more
Caused by: java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:530)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:494)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:608)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:706)
at org.apache.hadoop.ipc.Client$Connection.access$2800(Client.java:369)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1522)
at org.apache.hadoop.ipc.Client.call(Client.java:1439)
... 25 more
我们可以看到，连接job history server失败。
输入jps，看有哪些java进程：
23923 QuorumPeerMain
65477 Jps
28614 ResourceManager
28456 SecondaryNameNode
28239 NameNode
真的没有启动job history service。
解决方案：
启动historyserver：
sbin/mr-jobhistory-daemon.sh start historyserver