how to find the id of each map task?

I want to get the id of each mapper and reducer task because I want to tag the output of these mappers and reducers according to the mapper and reducer id. How can I retrieve the ids of each?

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You can print taskId in map, setup etc. functions by utilizing following code.

context.getTaskAttemptID().getTaskID();

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you can do it using: org.apache.hadoop.mapreduce.MapContext::getTaskAttemptID().