How to explicitly specify map node or reduce node in Hadoop

Question

is there any .xml file or something similar which explicitly specify that are nodes where I want to run Map task or Reduce Task. if this is hadoop architecture dependent then how can specify nodes.

Answer 1

No, there is no such feature.

I doubt if such a feature will ever be created because this would break the scalability and fault tolerance properties.

Answer 2

you need not specify the node on which you want to run the tasks. Hadoop map-reduce does it by itself.