running hadoop wordcount program - hadoop

Question

I am learning hadoop by following michael-noll tutorials. When I tried to run wordcount example by running hadoop jar hadoop-examples-1.2.1.jar wordcount tmp/Files tmp/Output I am getting following error:
13/11/10 18:09:42 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:54311. Already tried 0 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1 SECONDS)
.
.
13/11/10 18:09:51 ERROR security.UserGroupInformation: PriviledgedActionException as:hduser cause:java.net.ConnectException: Call to localhost/127.0.0.1:54311 failed on connection exception: java.net.ConnectException: Connection refused
java.net.ConnectException: Call to localhost/127.0.0.1:54311 failed on connection exception: java.net.ConnectException: Connection refused at
org.apache.hadoop.ipc.Client.wrapException(Client.java:1142)
at org.apache.hadoop.ipc.Client.call(Client.java:1118)
at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:229)
at org.apache.hadoop.mapred.$Proxy2.getProtocolVersion(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:85)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:62)
at org.apache.hadoop.mapred.$Proxy2.getProtocolVersion(Unknown Source)
at org.apache.hadoop.ipc.RPC.checkVersion(RPC.java:422)
at org.apache.hadoop.mapred.JobClient.createProxy(JobClient.java:559)
at org.apache.hadoop.mapred.JobClient.init(JobClient.java:498)
at org.apache.hadoop.mapred.JobClient.(JobClient.java:479)
at org.apache.hadoop.mapreduce.Job$1.run(Job.java:563)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1190)
at org.apache.hadoop.mapreduce.Job.connect(Job.java:561)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:549)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:580)
at org.apache.hadoop.examples.WordCount.main(WordCount.java:82)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68)
at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139)
at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:64)
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.util.RunJar.main(RunJar.java:160)
caused by: java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:708)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:511)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:481)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:457)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:583)
at org.apache.hadoop.ipc.Client$Connection.access$2200(Client.java:205)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1249)
at org.apache.hadoop.ipc.Client.call(Client.java:1093)
... 33 more
Addendum
I just re-ran the commands like this bin/stop-all.sh, bin/start-all.sh, hadoop jar hadoop-examples-1.2.1.jar wordcount tmp/Files tmp/Output. But now am getting following error :
13/11/10 20:52:12 ERROR security.UserGroupInformation: PriviledgedActionException as:hduser cause:org.apache.hadoop.ipc.RemoteException: org.apache.hadoop.mapred.SafeModeException: JobTracker is in safe mode
at org.apache.hadoop.mapred.JobTracker.checkSafeMode(JobTracker.java:5188)
at org.apache.hadoop.mapred.JobTracker.getStagingAreaDir(JobTracker.java:3677)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:587)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1432)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1428)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1190)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1426)
org.apache.hadoop.ipc.RemoteException: org.apache.hadoop.mapred.SafeModeException: JobTracker is in safe mode
at org.apache.hadoop.mapred.JobTracker.checkSafeMode(JobTracker.java:5188)
at org.apache.hadoop.mapred.JobTracker.getStagingAreaDir(JobTracker.java:3677)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Plz help

Answer 1

Try to manually turn off safe mode:
hadoop dfsadmin -safemode off
or
hadoop dfsadmin -safemode leave
Then rerun your job.

Answer 2

This is because your JobTracker is in safemode, and not the nameNode. Use the following command to make sure JT is not in safemode :
bin/hadoop mradmin -safemode leave
You can anytime use the below shown commands to check if your NN and JT are out of the safemode or not ;
bin/hadoop mradmin -safemode get
bin/hadoop dfsadmin -safemode get
Also, please make sure that you are using correct user to start the daemons.
#Praveen Sripati : Please see the second last option.