mapred.map.tasks 改版后變成了 mapreduce.job.maps
mapred.reduce.tasks 改版后變成了 mapreduce.job.reduces

MR 文檔
Apache 的官方文檔鏈接:
https://hadoop.apache.org/docs/r2.7.2/hadoop-mapreduce-client/hadoop-mapreduce-client-core/
mapred.map.tasks 改版后變成了 mapreduce.job.maps
mapred.reduce.tasks 改版后變成了 mapreduce.job.reduces
Apache 的官方文檔鏈接:
https://hadoop.apache.org/docs/r2.7.2/hadoop-mapreduce-client/hadoop-mapreduce-client-core/