I'm trying to submit a job (a simple word count) to hadoop-2.5.0 (installed on a ubuntu 14.04.1 server running on a virtual machine) from eclipse on windows. In the job configuration, i've set "fs.defaultFS" to "hdfs://192.168.2.216:8020" (as suggested in this thread) but when I run the main progam I got the following exception:
WARN - NativeCodeLoader - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
ERROR - Shell - Failed to locate the winutils binary in the hadoop binary path
Exception in thread "main" java.net.ConnectException: Call From EL-OUED/192.168.2.8 to 192.168.2.216:8020 failed on connection exception: java.net.ConnectException: Connection refused: no further information; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
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 org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:783)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:730)
at org.apache.hadoop.ipc.Client.call(Client.java:1414)
at org.apache.hadoop.ipc.Client.call(Client.java:1363)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206)
at com.sun.proxy.$Proxy14.getFileInfo(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:190)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:103)
at com.sun.proxy.$Proxy14.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:699)
at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1762)
at org.apache.hadoop.hdfs.DistributedFileSystem$17.doCall(DistributedFileSystem.java:1124)
at org.apache.hadoop.hdfs.DistributedFileSystem$17.doCall(DistributedFileSystem.java:1120)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1120)
at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1398)
at org.apache.hadoop.mapreduce.lib.output.FileOutputFormat.checkOutputSpecs(FileOutputFormat.java:145)
at org.apache.hadoop.mapreduce.JobSubmitter.checkSpecs(JobSubmitter.java:458)
at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:343)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1285)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1282)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1556)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:1282)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1303)
at com.heavenize.hadoop.WordCountMR.main(WordCountMR.java:55)
Caused by: java.net.ConnectException: Connection refused: no further information
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:735)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:529)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:493)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:604)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:699)
at org.apache.hadoop.ipc.Client$Connection.access$2800(Client.java:367)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1462)
at org.apache.hadoop.ipc.Client.call(Client.java:1381)
... 28 more
Also, when checking connection configuration on hadoop, it seems it is listening/accepting for connections on 127.0.0.1:8020.
$netstat -lent | grep 8020
tcp 0 0 127.0.0.1:8020 0.0.0.0:* LISTEN 1001 10380
This is the content of core-site.xml, I wonder if it is the source of this problem and how to fix it?
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost</value>
</property>
</configuration>
Basically your namenode is listening on the localhost interface, therefore it allows connections only from 127.0.0.1. As you suggested, the error is indeed in the fs.default.name parameter, which should be modified to use the hostname instead of localhost.
Beware that /etc/hosts should contain a line like
192.168.2.216 hostname.fully.qualified.domain.com hostname
You can verify that the hostname is properly setting running the command "hostname" and "hostname -f". "hostname" should return the the name of the system as returned by gethostname, while "hostname -f" should return the fqdn of the system.