If your cluster is not big enough (thousands of nodes) then there should be no problem in running NN & JT on same machine. I usually run my smaller clusters of size 10-20 nodes with NN & JT on same machine.
Usually bigger clusters have millions of HDFS files and it takes lots of NN memory that's why it is suggested to use different machines for NN & JT. Thanks, Ravi On 3/29/10 1:01 PM, "Edson Ramiro" <[email protected]> wrote: Hi all, Is there any problem in configure NameNode and JobTracker in the same machine? The documentation[1] Says that: "Typically one machine in the cluster is designated as the NameNode and another machine the as JobTracker..." But it doesn't say that we need to have one machine to each service. Thanks in Advance. [1] http://hadoop.apache.org/common/docs/current/cluster_setup.html Edson Ramiro
