I use Hadoop 2.2.0, I know hadoop will execute map first,when map is 100%, it then execute reduce, after reduce is 100%,job will end. I execute a job,the map is from 0% to 100% and map is from 0% to 100% again, why map execute twice? Thanks.
Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 1 2014-04-22 19:08:49,118 Stage-1 map = 0%, reduce = 0% 2014-04-22 19:11:46,722 Stage-1 map = 100%, reduce = 0% 2014-04-22 19:12:27,633 Stage-1 map = 0%, reduce = 0% 2014-04-22 19:14:37,655 Stage-1 map = 15%, reduce = 0%, Cumulative CPU 1.5 sec 2014-04-22 19:15:39,248 Stage-1 map = 33%, reduce = 0%, Cumulative CPU 3.34 sec 2014-04-22 19:15:59,395 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 3.34 sec 2014-04-22 19:16:40,988 Stage-1 map = 0%, reduce = 0% 2014-04-22 19:18:56,845 Stage-1 map = 11%, reduce = 0%, Cumulative CPU 2.57 sec 2014-04-22 19:19:46,574 Stage-1 map = 15%, reduce = 0%, Cumulative CPU 2.73 sec 2014-04-22 19:20:30,718 Stage-1 map = 22%, reduce = 0%, Cumulative CPU 2.82 sec 2014-04-22 19:20:35,007 Stage-1 map = 41%, reduce = 0%, Cumulative CPU 3.57 sec 2014-04-22 19:20:55,280 Stage-1 map = 45%, reduce = 0%, Cumulative CPU 3.76 sec 2014-04-22 19:21:27,247 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 4.41 sec 2014-04-22 19:22:28,362 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 4.41 sec 2014-04-22 19:22:49,170 Stage-1 map = 100%, reduce = 67%, Cumulative CPU 4.41 sec 2014-04-22 19:22:52,995 Stage-1 map = 100%, reduce = 100%, Cumulative CPU 5.69 sec MapReduce Total cumulative CPU time: 5 seconds 690 msec Ended Job = job_1398218615130_0001 --------------------------------------------------------------------------------------------------- Confidentiality Notice: The information contained in this e-mail and any accompanying attachment(s) is intended only for the use of the intended recipient and may be confidential and/or privileged of Neusoft Corporation, its subsidiaries and/or its affiliates. If any reader of this communication is not the intended recipient, unauthorized use, forwarding, printing, storing, disclosure or copying is strictly prohibited, and may be unlawful.If you have received this communication in error,please immediately notify the sender by return e-mail, and delete the original message and all copies from your system. Thank you. ---------------------------------------------------------------------------------------------------
