@Override public void map(Text key, Text val, Context context) throws IOException, InterruptedException { Configuration conf = context.getConfiguration(); UUID randomUuid = UUID.randomUUID(); TaskAttemptID taskAttemptId = context.getTaskAttemptID(); Long mostSignificant = (long) taskAttemptId.hashCode(); Long leastSignificant = randomUuid.getLeastSignificantBits(); UUID uniquieId = new UUID(mostSignificant, leastSignificant); String delimeter = conf.get(DELIMITER_CONF); String value = val.toString(); String outputValue = uniquieId.toString() + delimeter + value; logger.debug("The UUID generated is " + uniquieId.toString() + "\nOutput is " + outputValue); context.write(null, new Text(outputValue)); }