Hi All, When hadoop started with Kerberos authentication hadoop fs commands work well but MR job fails.
Simple wordcount program fails at reducer stage giving follwoing exception : 013-05-28 17:43:58,896 WARN org.apache.hadoop.mapred. ReduceTask: attempt_201305281729_0003_r_000000_1 copy failed: attempt_201305281729_0003_m_000000_0 from 192.168.49.51 2013-05-28 17:43:58,897 WARN org.apache.hadoop.mapred.ReduceTask: java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351) at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) at java.net.Socket.connect(Socket.java:529) 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:970) at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:911) at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:836) at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getInputStream(ReduceTask.java:1618) at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.setupSecureConnection(ReduceTask.java:1575) at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.getMapOutput(ReduceTask.java:1483) at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.copyOutput(ReduceTask.java:1394) at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$MapOutputCopier.run(ReduceTask.java:1326) Please provide some inputs to fix the issue. Thanks