hadoop從集群中怎么移除一個節點

本篇內容主要講解“hadoop從集群中怎么移除一個節點”，感興趣的朋友不妨來看看。本文介紹的方法操作簡單快捷，實用性強。下面就讓小編來帶大家學習“hadoop從集群中怎么移除一個節點”吧!

1.首先檢查整個集群的Average block replication，如果大于2，那即使直接拔出一個節點也不會丟失數據

hadoop fsck / 檢查集群的文件系統狀況

可以手動設置文件的冗余倍數，為了安全備份，可對關鍵數據hadoop fs -setrep -w 3 -R <path>

2.給下面兩個文件增加配置，在excludes中填寫要解任的節點名

mapred-site.xml

<property>

  <name>mapred.hosts</name>

  <value></value>

  <description>Names a file that contains the list of nodes that may

  connect to the jobtracker.  If the value is empty, all hosts are

  permitted.</description>

</property>

<property>

  <name>mapred.hosts.exclude</name>

  <value>HADOOP_HOME/conf/excludes</value>

  <description>Names a file that contains the list of hosts that

  should be excluded by the jobtracker.  If the value is empty, no

  hosts are excluded.</description>

</property>

hdfs-site.xml

<property>

  <name>dfs.hosts</name>

  <value></value>

  <description>Names a file that contains a list of hosts that are

  permitted to connect to the namenode. The full pathname of the file

  must be specified.  If the value is empty, all hosts are

  permitted.</description>

</property>

<property>

  <name>dfs.hosts.exclude</name>

  <value>HADOOP_HOME/conf/excludes</value>

  <description>Names a file that contains a list of hosts that are

  not permitted to connect to the namenode.  The full pathname of the

  file must be specified.  If the value is empty, no hosts are

  excluded.</description>

</property> 

excludes 文件里面配置機器的hostname即可。

run on namenode:   hadoop dfsadmin -refreshNodes  

run on jobtracker:   hadoop mradmin -refreshNodes 

“hadoop dfsadmin -refreshNodes”會觸發Decommission過程，在Decommission過程，集群會將Decommission節點上的數據冗余到其他幾點上，

到此，相信大家對“hadoop從集群中怎么移除一個節點”有了更深的了解，不妨來實際操作一番吧！這里是億速云網站，更多相關內容可以進入相關頻道進行查詢，關注我們，繼續學習！