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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/105/
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(Updated 2010-11-16 18:01:44.268029)


Review request for hadoop-hdfs.


Changes
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Incorporated Dhruba's feedback. Thank you!


Summary
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This patch introduces a new configuration variable 
dfs.namenode.replqueue.threshold-pct that determines the fraction of blocks for 
which block reports have to be received before the NameNode will start 
initializing the needed replication queues. Once a sufficient number of block 
reports have been received, the queues are initialized while the NameNode is 
still in safe mode. After the queues are initialized, subsequent block reports 
are handled by updating the queues incrementally.

The benefit of this is twofold:
- It allows us to compute the replication queues while we are waiting for the 
last few block reports (when the NameNode is mostly idle). Once these block 
reports have been received, we can then immediately leave safe mode without 
having to wait for the computation of the needed replication queues (which 
requires a full traversal of the blocks map).
- With Raid, it may not be necessary to stay in safe mode until all blocks have 
been reported. Using this change, we could monitor if all of the missing blocks 
can be recreated using parity information and if so leave safe mode early. In 
order for this monitoring to work, we need access to the needed replication 
queues while the NameNode is still in safe mode.


This addresses bug HDFS-1476.
    https://issues.apache.org/jira/browse/HDFS-1476


Diffs (updated)
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http://svn.apache.org/repos/asf/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/DFSConfigKeys.java
 1035545 
  
http://svn.apache.org/repos/asf/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/BlockManager.java
 1035545 
  
http://svn.apache.org/repos/asf/hadoop/hdfs/trunk/src/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
 1035545 
  
http://svn.apache.org/repos/asf/hadoop/hdfs/trunk/src/test/hdfs/org/apache/hadoop/hdfs/MiniDFSCluster.java
 1035545 
  
http://svn.apache.org/repos/asf/hadoop/hdfs/trunk/src/test/hdfs/org/apache/hadoop/hdfs/server/namenode/TestListCorruptFileBlocks.java
 1035545 

Diff: https://reviews.apache.org/r/105/diff


Testing
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new test case in TestListCorruptFileBlocks


Thanks,

Patrick

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