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From Apache Wiki <wikidi...@apache.org>
Subject [Hadoop Wiki] Update of "NameNodeFailover" by CosminLehene
Date Wed, 14 May 2008 08:51:02 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for change notification.

The following page has been changed by CosminLehene:
http://wiki.apache.org/hadoop/NameNodeFailover

The comment on the change is:
Question/idea regarding the name node failover

------------------------------------------------------------------------------
  In order to provide redundancy for data protection in case of namenode failure the best
way is to store the namenode metadata on a different machine.  Hadoop has an option to have
multiple namenode directories and the recommended option is to have one of the namenode directories
on an NFS share.  However you have to make sure the NFS locking will not cause problems and
it is NOT recommended to change this on a live system because it can corrupt namenode data.
 Another option is to simply copy namenode metadata to another machine.
  --Ankur Sethi
  
+ '''Question'''
+ 
+ Why not keep the fsimage and editlog in the DFS (somehow that they could be located by data
nodes without the name node)?
+ Then when then name node fails, by an election mechanism, a data node becomes the new name
node. 
+ --Cosmin Lehene
+  
+ 

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