hadoop-common-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <wikidi...@apache.org>
Subject [Lucene-hadoop Wiki] Update of "FAQ" by KonstantinShvachko
Date Fri, 05 Oct 2007 02:25:11 GMT
Dear Wiki user,

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

The following page has been changed by KonstantinShvachko:
http://wiki.apache.org/lucene-hadoop/FAQ

------------------------------------------------------------------------------
  
  In hadoop-0.15, Map / Reduce task completion graphics are added. The graphs are produced
as SVG(Scalable Vector Graphics) images, which are basically xml files, embedded in html content.
The graphics are tested successfully in Firefox 2 on Ubuntu and MAC OS. However for other
browsers, one should install an additional plugin to the browser to see the SVG images. Adobe's
SVG Viewer can be found at [http://www.adobe.com/svg/viewer/install/]. 
  
+ 
+ 
+ [[BR]]
+ [[Anchor(12)]]
+ '''12. [#12 Does the name-node stay in safe mode till all under-replicated files are fully
replicated?]'''
+ 
+ No. During safe mode replication of blocks is prohibited. 
+ The name-node awaits when all or majority of data-nodes report their blocks.
+ 
+ Depending on how safe mode parameters are configured the name-node will stay in safe mode

+ until a specific percentage of blocks of the system is ''minimally'' replicated 
+ [http://lucene.apache.org/hadoop/hadoop-default.html#dfs.replication.min dfs.replication.min].
+ If the safe mode threshold 
+ [http://lucene.apache.org/hadoop/hadoop-default.html#dfs.safemode.threshold.pct dfs.safemode.threshold.pct]

+ is set to 1 then all blocks of all 
+ files should be minimally replicated.
+ 
+ Minimal replication does not mean full replication. Some replicas may be missing and in

+ order to replicate them the name-node needs to leave safe mode.
+ 
+ Learn more about safe mode
+ [http://lucene.apache.org/hadoop/api/org/apache/hadoop/dfs/NameNode.html#setSafeMode(org.apache.hadoop.dfs.FSConstants.SafeModeAction)
   here].
+ 

Mime
View raw message