On 8 October 2012 14:23, Shinichi Yamashita <[email protected]> wrote:
> Hi, > > 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. steve
