Hi, I've some question about the MapRed ports and how a reduce knows where the map output is to fetch.
I know that MapRed uses jetty has a webserver. - The JobTracker send tasks to the TaskTracker execute them through port 50060? - Which port TaskTracker uses to send status about the task that its executing to the JobTracker? Is it through port 50030? - MapReduce uses the port 54311. What's the reason of this port? - The Reduce task in the shuffle phase must copy the map outputs. In which class is the part of the code where Reduce will fetch the map output? This part of the code is executed by the TaskTracker process? - The directory where the map output is to the reduce task use, is sent by the JobTracker? If so, this means that the JobTracker was informed by the task tracker where a map run, right? - The class org.apache.hadoop.mapred.ReduceTask is used? If so, which process use this class? Is it the TaskTracker process? Thanks, -- Pedro
