title: Hbase master not able to start regionserver
body: <p>I have one master and one regionserer running on one machine,now I want to add another region server to it.</p>
  
  <p>This new machine has all the connection config required (as in passwordless ssh etc), as these two machines are running datanodes for my underlying Hadoop (and start/stop from hadoop master starts/stops datanodes on all the machines).</p>
  
  <p>I have mentioned two servers (with their entries in /etc/hosts):</p>
  
  <pre><code>master
  slave
  </code></pre>
  
  <p>Now if I do ./start-hbase.sh on the master In the console it says "starting regionserver on slave", but the corresponding log is empty and in the web console i do not see the slave as one of the regionservers (master region server starts fine).</p>
  
  <p>So I thought maybe I will start the region server manually on the slave and I did</p>
  
  <pre><code>./hbase-daemon.sh start regionserver
  </code></pre>
  
  <p>The region server starts but in the logs I see:</p>
  
  <pre><code>2011-09-05 14:28:54,331 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: Attempting connect to Master server at master:60000
  2011-09-05 14:28:54,501 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: Connected to master at master:60000
  2011-09-05 14:28:54,672 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: Telling master at master:60000 that we are up
  2011-09-05 14:28:54,757 WARN org.apache.hadoop.hbase.regionserver.HRegionServer: error telling master we are up
  java.io.IOException: Call to master/174.129.183.20:60000 failed on local exception: java.io.EOFException
          at org.apache.hadoop.hbase.ipc.HBaseClient.wrapException(HBaseClient.java:806)
          at org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:775)
          at org.apache.hadoop.hbase.ipc.HBaseRPC$Invoker.invoke(HBaseRPC.java:257)
          at $Proxy5.regionServerStartup(Unknown Source)
          at org.apache.hadoop.hbase.regionserver.HRegionServer.reportForDuty(HRegionServer.java:1538)
          at org.apache.hadoop.hbase.regionserver.HRegionServer.tryReportForDuty(HRegionServer.java:1499)
          at org.apache.hadoop.hbase.regionserver.HRegionServer.run(HRegionServer.java:572)
          at java.lang.Thread.run(Thread.java:662)
  Caused by: java.io.EOFException
          at java.io.DataInputStream.readInt(DataInputStream.java:375)
          at org.apache.hadoop.hbase.ipc.HBaseClient$Connection.receiveResponse(HBaseClient.java:539)
          at org.apache.hadoop.hbase.ipc.HBaseClient$Connection.run(HBaseClient.java:477)
  </code></pre>
  
  <p>I thought may be if I restarted the hbase master it will recognize the regionserver, but when I do that I get an error "Region server started on slave with pid:xxx, stop it first".</p>
  
  <p>What am I missing here, I am using exactly the same hbase-site.xml file on both the machines. Please help</p>