On 8 October 2012 14:23, Shinichi Yamashita <[EMAIL PROTECTED]> wrote:
> I know that DataNode and TaskTracker must restart to change topology.
no, it's the Namenode and JobTracker that needs to be restarted; they are
the bits that care where the boxes are.
> Is there the method to execute the topology change without restart of
> DataNode and TaskTracker?
> In other words, can I change the topology by a command?
No -the map gets cached, and when the services start up they do quick check
to see if the topology is flat or spread across switches -and use that flag
to make various placement decisions.