I don't know the answers to your questions. I learned what I know by grepping through the DataNode.java source for "rack".
To use it, I set the "dfs.network.script" property in my hadoop config. This contains the path to an executable which prints the name of the rack. There's also a way to pass it on the command line to the DataNode class, so it depends on how you start up your datanodes, I suppose. -Michael On 9/6/07 3:35 PM, "Torsten Curdt" <[EMAIL PROTECTED]> wrote: > Is there a jira issue for it already? > > Whom could I bug (bribe?) to document the rack-awareness feature? :) > > cheers > -- > Torsten > > On 07.09.2007, at 00:26, Michael Bieniosek wrote: > >> Well, there is an (undocumented?) way to get rack-awareness in the >> Datanode, >> so you could co-opt this to represent datacenter-awareness. I >> don't think >> there is such a rack-awareness ability for the DFSClient or >> TaskTracker >> though. >> >> -Michael >> >> On 9/6/07 3:10 PM, "Torsten Curdt" <[EMAIL PROTECTED]> wrote: >> >>>> Another big question: Has anybody tried using HADOOP / HDFS across >>>> multiple geographic sites? >>> >>> That's actually a biggy I would be very much interested in, too >>> >>> cheers >>> -- >>> Torsten >> >
