title: HADOOP / YARN - Are the ResourceManager and the hdfs NameNode always installed on the same host?
body: <p>Are the “resource manager” and the “hdfs namenode” always installed on the same host?</p>
  
  <p>1)  When I want to send an http request (YARN REST API) to <a href="http://hadoop.apache.org/docs/current/hadoop-yarn/hadoop-yarn-site/ResourceManagerRest.html#Cluster_New_Application_API" rel="noreferrer">get new application id</a> I am using this web uri:</p>
  
  <pre><code>http://&lt;rm http address:port&gt;/ws/v1/cluster/apps/new-application
  </code></pre>
  
  <p>This port is the Resource-Manager Web UI http port, it’s default value is 8088 as shown in img1: <a href="http://docs.hortonworks.com/HDP2Alpha/index.htm#Appendix/Ports_Appendix/YARN_Ports.htm" rel="noreferrer">source for img1</a><img src="https://i.stack.imgur.com/mm1ku.jpg" alt="Yarn Ports"></p>
  
  <p>2)  When I want to send an http request (WebHDFS REST API) for hdfs commands, for example to <a href="http://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-hdfs/WebHDFS.html#Status_of_a_FileDirectory" rel="noreferrer">get file status</a> I am using this web uri:</p>
  
  <pre><code>http://&lt;HOST&gt;:&lt;PORT&gt;/webhdfs/v1/&lt;PATH&gt;?op=GETFILESTATUS
  </code></pre>
  
  <p>This <code>&lt;PORT&gt;</code> is the NameNode WebUI http Port, it’s default value is 50070 as shown in img2: <a href="http://docs.hortonworks.com/HDP2Alpha/index.htm#Appendix/Ports_Appendix/HDFS_Ports.htm" rel="noreferrer">source for img2</a>
  <img src="https://i.stack.imgur.com/7ATaY.jpg" alt="HDFS Ports"></p>
  
  <p>Are the hosts of those components (ResourceManager and NaneNode) are always installed on the same host?</p>
  
  <p>Any help would be appreciated, Thanks!</p>