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Re: Problem in reduce phase
The error message: "Caused by: java.net.ConnectException: Connection
refused" means that there is some problem in communication between the
nodes in cluster.

On Fri, Feb 3, 2012 at 3:26 AM, hadoop hive <[EMAIL PROTECTED]> wrote:

> hey folks,
>
> i m getting this error while running mapreduce and these comes up in reduce
> phase..
>
>
> 2012-02-03 16:41:19,780 WARN org.apache.hadoop.mapred.ReduceTask:
> attempt_201201271626_5282_r_000000_0 copy failed:
> attempt_201201271626_5282_m_000007_2 from hadoopdata3
> 2012-02-03 16:41:19,954 WARN org.apache.hadoop.mapred.ReduceTask:
> java.net.ConnectException: Connection refused
>        at sun.reflect.GeneratedConstructorAccessor8.newInstance(Unknown
> Source)
>        at
> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
>        at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
>        at
> sun.net.www.protocol.http.HttpURLConnection$6.run(HttpURLConnection.java:1345)
>        at java.security.AccessController.doPrivileged(Native Method)
>        at
> sun.net.www.protocol.http.HttpURLConnection.getChainedException(HttpURLConnection.java:1339)
>        at
> sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:993)
>        at
> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getInputStream(ReduceTask.java:1447)
>        at
> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getMapOutput(ReduceTask.java:1349)
>        at
> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.copyOutput(ReduceTask.java:1261)
>        at
> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.run(ReduceTask.java:1195)
> Caused by: java.net.ConnectException: Connection refused
>        at java.net.PlainSocketImpl.socketConnect(Native Method)
>        at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
>        at
> java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
>        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
>        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
>        at java.net.Socket.connect(Socket.java:519)
>        at sun.net.NetworkClient.doConnect(NetworkClient.java:158)
>        at sun.net.www.http.HttpClient.openServer(HttpClient.java:394)
>        at sun.net.www.http.HttpClient.openServer(HttpClient.java:529)
>        at sun.net.www.http.HttpClient.<init>(HttpClient.java:233)
>        at sun.net.www.http.HttpClient.New(HttpClient.java:306)
>        at sun.net.www.http.HttpClient.New(HttpClient.java:323)
>        at
> sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:837)
>        at
> sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:778)
>        at
> sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:703)
>        at
> sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1026)
>        ... 4 more
>
> 2012-02-03 16:41:19,995 INFO org.apache.hadoop.mapred.ReduceTask: Task
> attempt_201201271626_5282_r_000000_0: Failed fetch #4 from
> attempt_201201271626_5282_m_000007_2
> 2012-02-03 16:41:19,995 INFO org.apache.hadoop.mapred.ReduceTask:
> Failed to fetch map-output from attempt_201201271626_5282_m_000007_2
> even after MAX_FETCH_RETRIES_PER_MAP retries...  reporting to the
> JobTracker
> 2012-02-03 16:41:19,995 WARN org.apache.hadoop.mapred.ReduceTask:
> attempt_201201271626_5282_r_000000_0 adding host hadoopdata3 to
> penalty box, next contact in 150 seconds
> 2012-02-03 16:41:19,995 INFO org.apache.hadoop.mapred.ReduceTask:
> attempt_201201271626_5282_r_000000_0: Got 1 map-outputs from previous
> failures
> 2012-02-03 16:42:10,015 INFO org.apache.hadoop.mapred.ReduceTask:
> attempt_201201271626_5282_r_000000_0 Need another 1 map output(s)
> where 0 is already in progress
> 2012-02-03 16:42:10,015 INFO org.apache.hadoop.mapred.ReduceTask:
> attempt_201201271626_5282_r_000000_0 Scheduled 0 outputs (1 slow hosts

Thanks & Regards,
Anil Gupta