title: Failed to read data from a hadoop URL
body: <p>I am following Tom White's 'Hadoop - The Definitive Guide'. 
  When I try to use the Java Interface to read data from a hadoop URL I get the following error message:</p>
  
  <pre><code>hadoop@ubuntu:/usr/local/hadoop$ hadoop URLCat hdfs://master/hdfs/data/SampleText.txt
  12/11/21 13:46:32 INFO ipc.Client: Retrying connect to server: master/192.168.9.55:8020. Already tried 0 time(s).
  12/11/21 13:46:33 INFO ipc.Client: Retrying connect to server: master/192.168.9.55:8020. Already tried 1 time(s).
  12/11/21 13:46:34 INFO ipc.Client: Retrying connect to server: master/192.168.9.55:8020. Already tried 2 time(s).
  12/11/21 13:46:35 INFO ipc.Client: Retrying connect to server: master/192.168.9.55:8020. Already tried 3 time(s).
  12/11/21 13:46:36 INFO ipc.Client: Retrying connect to server: master/192.168.9.55:8020. Already tried 4 time(s).
  12/11/21 13:46:37 INFO ipc.Client: Retrying connect to server: master/192.168.9.55:8020. Already tried 5 time(s).
  </code></pre>
  
  <p>The Contents of the URLCat file are as follows:</p>
  
  <pre><code>import java.net.URL;
  import java.io.InputStream;
  import org.apache.hadoop.io.IOUtils;
  import org.apache.hadoop.fs.FsUrlStreamHandlerFactory;
  
  public class URLCat {
  static {
      URL.setURLStreamHandlerFactory(new FsUrlStreamHandlerFactory());
  }
  
  public static void main(String[] args) throws Exception {
      InputStream in = null;
      try {
          in = new URL(args[0]).openStream();
          IOUtils.copyBytes(in, System.out, 4096, false);
      } finally {
          IOUtils.closeStream(in);
      }
  }
  }
  </code></pre>
  
  <p>The /etc/hosts file contents are:</p>
  
  <pre><code>127.0.0.1   localhost
  127.0.1.1   ubuntu.ubuntu-domain    ubuntu
  
  # The following lines are desirable for IPv6 capable hosts
  ::1     ip6-localhost ip6-loopback
  fe00::0 ip6-localnet
  ff00::0 ip6-mcastprefix
  ff02::1 ip6-allnodes
  ff02::2 ip6-allrouters
  
  # /ect/hosts Master and slaves
  192.168.9.55    master
  192.168.9.56    slave1
  192.168.9.57    slave2
  192.168.9.58    slave3
  </code></pre>