I'm trying to modify Hadoop in a way that requires that the DataNode be aware of the MapReduce job that initiated a block request (e.g. fetching an input split for a map task). My understanding of the code is limited, but as far as I can tell, this information doesn't reach the DataNode, which only sees generic requests made by the DFSClient. So, what I'd like to know is how requests originating from the TaskTracker make their way to the DataNode. Any help would be appreciated.
Adrian
