title: Hadoop: Conflict in JPS and hdfs admin report for checking the number of available data nodes
body: <p>I am working on a five node hadoop multinode cluster. After setting up the clusers, I used JPS command to check whether all of the nodes are properly connected/not. Following were the results after running JPS command in one master node and all the other four slave nodes respectively.</p>
  
  <p><strong>master node</strong></p>
  
  <pre><code>8825 SecondaryNameNode
  8647 DataNode
  9105 NodeManager
  9418 Jps
  8493 NameNode
  8971 ResourceManager
  </code></pre>
  
  <p><strong>slave nodes</strong></p>
  
  <pre><code>1816 NodeManager
  1711 DataNode
  2154 Jps
  </code></pre>
  
  <p>But when I tried checking from the command <strong>hdfs dfsadmin -report</strong>, I got the following result:</p>
  
  <pre><code>Configured Capacity: 242317230080 (225.68 GB)
  Present Capacity: 224333357056 (208.93 GB)
  DFS Remaining: 224333332480 (208.93 GB)
  DFS Used: 24576 (24 KB)
  DFS Used%: 0.00%
  Under replicated blocks: 0
  Blocks with corrupt replicas: 0
  Missing blocks: 0
  
  -------------------------------------------------
  Datanodes available: 1 (1 total, 0 dead)
  
  Live datanodes:
  Name: 127.0.0.1:50010 (localhost)
  Hostname: localhost
  Decommission Status : Normal
  Configured Capacity: 242317230080 (225.68 GB)
  DFS Used: 24576 (24 KB)
  Non DFS Used: 17983873024 (16.75 GB)
  DFS Remaining: 224333332480 (208.93 GB)
  DFS Used%: 0.00%
  DFS Remaining%: 92.58%
  Configured Cache Capacity: 0 (0 B)
  Cache Used: 0 (0 B)
  Cache Remaining: 0 (0 B)
  Cache Used%: 100.00%
  Cache Remaining%: 0.00%
  </code></pre>
  
  <p>I am unable to understand as to why the <strong>Data nodes available</strong> is shown as 1 in the above report. Also, my program is running very slow and so I guess only of the datanodes is active. Kindly mention the cause behind this anomaly.</p>