NN refers to the rack topology script/class when a new node joins (i.e. it doesn't have the node's IP already in cache), when it starts up, and (I think) also when you issue -refreshNodes.
The ideal way to "add" a node to the rack right now is to first update the rack config at the NN, then boot the DN up. On Thu, Feb 21, 2013 at 1:47 AM, Chris Embree <cemb...@gmail.com> wrote: > I've checked all of the documentation, books and google searches I can think > of.... > > I have a working topology script. I have dynamic IP's. I have an automated > process to update the rack data when a datanode changes IP. > > What I don't have is any clue as to when the NN reads this script. If I > execute it right now with 10.10.10.10 it'll return /dc1/rack3 When I run > hadoop balancer I see /default/rack/10.10.10.10:50010 > I really don't want to have to restart the NN for IP changes to be noticed. > > Any brilliant insights? > > Thanks > Chris -- Harsh J