Check out the chooseTarget() method(s) of ReplicationTargetChooser.java in
the org.apache.hadoop.hdfs.server.namenode package:
In words: assuming you're using the default replication level (3), the
default strategy will put one block on the local node, one on a node in a
remote rack, and another on that same remote rack.
Note that HADOOP-3799 (http://issues.apache.org/jira/browse/HADOOP-3799)
proposes making this strategy pluggable.
As for the example of a topology.script file, I'll let others handle that.
On Sun, May 10, 2009 at 11:20 PM, Vishal Ghawate <
[EMAIL PROTECTED]> wrote:
> i just cant resolve how the namenode decide on where to place the replicas
> of the datanode
> can u also send me the example of the topology.script.file
> and how exactly it works
> thanks for referring my problem
> Vishal S. Ghawate
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