It isn't the NN that does the SSH technically, its the scripts we ship for an easier start/stop: http://wiki.apache.org/hadoop/FAQ#Does_Hadoop_require_SSH.3F
So wherever you launch the script, the SSH may happen from that point. On Wed, Feb 6, 2013 at 4:36 AM, Jay Vyas <[email protected]> wrote: > When setting up passwordless ssh on a cluster, its clear that the namenode > needs to be able to ssh into task trackers to start/stop nodes and restart > the cluster. > > What else is passwordless SSH used for? Do TaskTrackers/DataNodes ever SSH > into each other horizontally ? Or is SSH only used for one-way nn to tt > operations? > > -- > Jay Vyas > http://jayunit100.blogspot.com -- Harsh J
