Call From kv.local/172.20.12.168 to localhost:8020 failed on connection exception, when using tera gen

I am working with hadoop teragen to check the hadoop mapreduce benchmarking with the terasort. But when i run the following command,

hadoop jar /Users/**/Documents/hadoop-2.6.4/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.6.4.jar teragen -Dmapreduce.job.maps=100 1t random-data

I got the following exception,

17/06/01 15:09:21 WARN util.NativeCodeLoader: Unable to load native-hadoop 
library for your platform... using builtin-java classes where applicable
17/06/01 15:09:22 INFO client.RMProxy: Connecting to ResourceManager at /127.0.0.1:8032
17/06/01 15:09:23 INFO terasort.TeraSort: Generating -727379968 using 100
17/06/01 15:09:23 INFO mapreduce.JobSubmitter: number of splits:100
17/06/01 15:09:23 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1496303775726_0003
17/06/01 15:09:23 INFO impl.YarnClientImpl: Submitted application application_1496303775726_0003
17/06/01 15:09:23 INFO mapreduce.Job: The url to track the job: http://localhost:8088/proxy/application_1496303775726_0003/
17/06/01 15:09:23 INFO mapreduce.Job: Running job: job_1496303775726_0003
17/06/01 15:09:27 INFO mapreduce.Job: Job job_1496303775726_0003 running in uber mode : false
17/06/01 15:09:27 INFO mapreduce.Job:  map 0% reduce 0%
17/06/01 15:09:27 INFO mapreduce.Job: Job job_1496303775726_0003 failed with state FAILED due to: Application application_1496303775726_0003 failed 2 times due to AM Container for appattempt_1496303775726_0003_000002 exited with  exitCode: -1000
For more detailed output, check application tracking page:http://localhost:8088/proxy/application_1496303775726_0003/Then, click on links to logs of each attempt.
Diagnostics: Call From KV.local/172.20.12.168 to localhost:8020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused
java.net.ConnectException: Call From KV.local/172.20.12.168 to localhost:8020 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$Invoker.invoke(ProtobufRpcEngine.java:232)
    at com.sun.proxy.$Proxy34.getFileInfo(Unknown Source)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:752)
    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.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:187)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
    at com.sun.proxy.$Proxy35.getFileInfo(Unknown Source)
    at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1977)
    at org.apache.hadoop.hdfs.DistributedFileSystem$18.doCall(DistributedFileSystem.java:1118)
    at org.apache.hadoop.hdfs.DistributedFileSystem$18.doCall(DistributedFileSystem.java:1114)
    at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
    at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1114)
    at org.apache.hadoop.yarn.util.FSDownload.copy(FSDownload.java:251)
    at org.apache.hadoop.yarn.util.FSDownload.access$000(FSDownload.java:61)
    at org.apache.hadoop.yarn.util.FSDownload$2.run(FSDownload.java:359)
    at org.apache.hadoop.yarn.util.FSDownload$2.run(FSDownload.java:357)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1656)
    at org.apache.hadoop.yarn.util.FSDownload.call(FSDownload.java:356)
    at org.apache.hadoop.yarn.util.FSDownload.call(FSDownload.java:60)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.ConnectException: Connection refused
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
    at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
    at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:530)
    at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:494)
    at org.apache.hadoop.ipc.Client$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)
    ... 31 more

As the error show, it is not able to connect to localhost:8020, but when i chech the namenode web UI, it shows that the namenode is active. Please see the below screenshot:

I found many posts related to this, but none helped me out. I also checked out the hosts file, which contains the following line:

127.0.0.1 localhost

172.20.12.168 localhost

Can anybody help me out sorting out this problem?

Solution

The following procedure helped me out in solving the issue:

Stop all the services.
Delete namenode and datanode directories as specified in hdfs-site.xml.
Create new namenode and datanode directories and modify hdfs-site.xml accordingly.

in core-site.xml, make the following changes or add the following properties:

<property>
  <name>fs.defaultFS</name>
  <value>hdfs://172.20.12.168/</value>
</property>
<property>
  <name>fs.default.name</name>
  <value>hdfs://172.20.12.168:8020</value>
</property>

Make the following changes in hadoop-2.6.4/etc/hadoop/hadoop-env.sh file:

export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_91.jdk/Contents/Home

Restart dfs, yarn and mr as follows:

 start-dfs.sh
 start-yarn.sh
 mr-jobhistory-daemon.sh start historyserver