How to get Hadoop task tracker info from inside a mapper or reducer

Question

Your Mapper and Reducer classes always run on a particular task tracker. But how do I get info on the task tracker? The only thing passed into the setup method is a TaskInputOutputContext. You can get the task attempt ID, but how do I map this to a TaskTracker object? (E.g. to get the hostname, the corresponding job tracker, etc. Yes I know you can get the hostname through java.net.InetAddress.getLocalHost().getHostName() but this is outside of Hadoop entirely.)

Answer 1

you can anytime got to the MapReduce web-ui and see all these information..just click on a job you want to analyze and then you can see almost everything for individual map and reduce tasks.