Thats what I thought too, but please check the Answer #2 here in this question , I am facing a similar problem.
http://stackoverflow.com/questions/12135949/why-map-task-always-running-on-a-single-node On Sat, Aug 23, 2014 at 12:44 PM, Chris MacKenzie < [email protected]> wrote: > Hi, > > The requirement is simply to have the slaves and masters files on the > resource manager it's used by the shell script that starts the demons :-) > > Sent from my iPhone > > On 23 Aug 2014, at 16:02, "S.L" <[email protected]> wrote: > > Ok, Ill copy the slaves file to the other slave nodes as well. > > What about the masters file though? > > Sent from my HTC > > ----- Reply message ----- > From: "rab ra" <[email protected]> > To: "[email protected]" <[email protected]> > Subject: Hadoop YARM Cluster Setup Questions > Date: Sat, Aug 23, 2014 5:03 AM > > Hi, > > 1. Typically,we used to copy the slaves file all the participating nodes > though I do not have concrete theory to back up this. Atleast, this is what > I was doing in hadoop 1.2 and I am doing the same in hadoop 2x > > 2. I think, you should investigate the yarn GUI and see how many maps it > has spanned. There is a high possibility that both the maps are running in > the same node in parallel. Since there are two splits, there would be two > map processes, and one node is capable of handling more than one map. > > 3. There could be no replica of input file stored and it is small, and > hence stored in a single block in one node itself. > > These could be few hints which might help you > > regards > rab > > > > On Sat, Aug 23, 2014 at 12:26 PM, S.L <[email protected]> wrote: > > > Hi Folks, > > > > I was not able to find a clear answer to this , I know that on the master > > node we need to have a slaves file listing all the slaves , but do we need > > to have the slave nodes have a master file listing the single name node( I > > am not using a secondary name node). I only have the slaves file on the > > master node. > > > > I was not able to find a clear answer to this ,the reason I ask this is > > because when I submit a hadoop job , even though the input is being split > > into 2 parts , only one data node is assigned applications , the other two > > ( I have three) are no tbeing assigned any applications. > > > > Thanks in advance! > > > >
