{"id":154,"date":"2018-03-12T13:51:14","date_gmt":"2018-03-12T05:51:14","guid":{"rendered":"http:\/\/www.max-shu.com\/blog\/?p=154"},"modified":"2018-03-12T13:51:14","modified_gmt":"2018-03-12T05:51:14","slug":"hadoop%e6%80%a7%e8%83%bd%e6%a8%a1%e5%9e%8b%ef%bc%881%ef%bc%89","status":"publish","type":"post","link":"http:\/\/www.max-shu.com\/blog\/?p=154","title":{"rendered":"Hadoop\u6027\u80fd\u6a21\u578b\uff081\uff09"},"content":{"rendered":"<p>MapReduce Job\u7684\u6267\u884c\u5206\u4e3amap\u4efb\u52a1\u548creduce\u4efb\u52a1\uff0cmap\u4efb\u52a1\u5206\u4e3a\u51e0\u4e2a\u9636\u6bb5\uff1aRead\uff08\u8bfbmap\u7684\u8f93\u5165\uff09\uff0cMap\uff08map\u51fd\u6570\u5904\u7406\uff09\uff0cCollect\uff08\u5e8f\u5217\u5316\u5230buffer\u548c\u5206\u533a\uff09\uff0cSpill\uff08\u6392\u5e8f\u3001\u7ec4\u5408\u3001\u538b\u7f29\u3001\u5199map\u8f93\u51fa\u5230\u672c\u5730\u78c1\u76d8\uff09\uff0cMerge\uff08\u5408\u5e76\u6392\u5e8f\u4e86\u7684spill\u6587\u4ef6\uff09\u3002Reduce\u4efb\u52a1\u5206\u4e3a\u51e0\u4e2a\u9636\u6bb5\uff1aShuffle\uff08\u4f20\u8f93map\u8f93\u51fa\u5230reduce\u4efb\u52a1\uff0c\u5fc5\u8981\u65f6\u89e3\u538b\u7f29\uff09\uff0cMerge\uff08\u5408\u5e76\u6392\u5e8f\u4e86\u7684map\u8f93\u51fa\uff09\uff0cReduce\uff08reduce\u51fd\u6570\u5904\u7406\uff09\uff0cWrite\uff08\u5199reduce\u8f93\u51fa\u5230\u5206\u5e03\u5f0f\u6587\u4ef6\u7cfb\u7edf\uff09\u3002<\/p>\n<p><b><span style=\"font-size: large;\">1. \u6a21\u578b\u53c2\u6570<\/span><\/b><\/p>\n<p>\u6027\u80fd\u6a21\u578b\u4f9d\u9760\u53c2\u6570\u96c6\u6765\u8bc4\u4f30MapReduce job\u7684\u6d88\u8017\uff0c\u628a\u53c2\u6570\u5206\u4e3a\u4e09\u4e2a\u8303\u7574\uff1a<br \/>\n1. Hadoop\u53c2\u6570\uff1a\u5f71\u54cdjob\u6267\u884c\u7684hadoop\u914d\u7f6e\u53c2\u6570\u3002<br \/>\n2. \u7edf\u8ba1\u5c5e\u6027\u53c2\u6570\uff1a\u8f93\u5165\u6570\u636e\u548c\u7528\u6237\u5b9a\u4e49\u51fd\u6570\u7684\u4e00\u4e9b\u7edf\u8ba1\u503c\u3002<br \/>\n3. \u6d88\u8017\u56e0\u5b50\u5c5e\u6027\u53c2\u6570\uff1a job\u6267\u884c\u671f\u95f4\u7684I\/O\uff0cCPU\uff0c\u7f51\u7edc\u7b49\u7684\u6d88\u8017\u3002<\/p>\n<p><b>Hadoop\u53c2\u6570\uff1a<\/b><br \/>\n<u><i>\u53d8\u91cf\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Hadoop\u53c2\u6570 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0 \u7f3a\u7701\u503c \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u5f71\u54cd<\/i><\/u><br \/>\npNumNodes\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u8282\u70b9\u6570 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0 \u00a0 \u00a0\u00a0 \u00a0 System<br \/>\npTaskMem\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.child.java.opts\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 -Xmx200m\u00a0\u00a0\u00a0\u00a0\u00a0 System<br \/>\npMaxMapsPerNode\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.tasktracker.map.tasks.max\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System<br \/>\npMaxRedPerNode\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.tasktracker.reduce.tasks.max\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0 System<br \/>\npNumMappers\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.map.tasks\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 Job<br \/>\npSortMB\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 io.sort.mb\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 100 MB\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Job<br \/>\npSpillPerc\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 io.sort.spill.percent\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.8\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Job<br \/>\npSortRecPerc\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 io.sort.record.percent\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.05\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Job<br \/>\npSortFactor\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 io.sort.factor\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 10\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Job<br \/>\npNumSpillsForComb\u00a0\u00a0\u00a0\u00a0\u00a0 min.num.spills.for.combine\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 3\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Job<br \/>\npNumReducers\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.reduce.tasks\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0 \u00a0 Job<br \/>\npInMemMergeThr\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.inmem.merge.threshold\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1000\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0 Job<br \/>\npShu?eInBufPerc\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.job.shuffle.input.buffer.percent\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 0.7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 Job<br \/>\npShu?eMergePerc\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.job.shuffle.merge.percent\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 0.66\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 Job<br \/>\npReducerInBufPerc\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.job.reduce.input.buffer.percent\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0\u00a0 Job<br \/>\npUseCombine\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0 mapred.combine.class or mapreduce.combine.class\u00a0 null\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 Job<br \/>\npIsIntermCompressed\u00a0\u00a0 mapred.compress.map.output\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 false\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0\u00a0 Job<br \/>\npIsOutCompressed\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.output.compress\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 false\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0\u00a0 Job<br \/>\npReduceSlowstart\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapred.reduce.slowstart.completed.maps\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0 0.05\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 Job<br \/>\npIsInCompressed\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u8f93\u5165\u662f\u5426\u538b\u7f29 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Input<br \/>\npSplitSize\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u8f93\u5165spilt\u7684\u5927\u5c0f \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Input<\/p>\n<p><b>\u7edf\u8ba1\u5c5e\u6027\u53c2\u6570\uff1a<\/b><u><br \/>\n<i>\u53d8\u91cf \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u63cf\u8ff0<\/i><\/u><br \/>\nsInputPairWidth\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u8f93\u5165kv\u5bf9\u7684\u5e73\u5747\u5bbd\u5ea6<br \/>\nsMapSizeSel\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapper \u5927\u5c0f<br \/>\nsMapPairsSel\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 mapper kv\u5bf9\u6570\u91cf<br \/>\nsReduceSizeSel\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 reducer \u5927\u5c0f<br \/>\nsReducePairsSel\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 reducer kv\u5bf9\u6570\u91cf<br \/>\nsCombineSizeSel\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 combine \u5927\u5c0f<br \/>\nsCombinePairsSel\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 combine kv\u5bf9\u6570\u91cf<br \/>\nsInputCompressRatio\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u8f93\u5165\u6570\u636e\u538b\u7f29\u7387<br \/>\nsIntermCompressRatio\u00a0\u00a0\u00a0\u00a0 \u4e2d\u95f4map\u8f93\u51fa\u538b\u7f29\u7387<br \/>\nsOutCompressRatio\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u6700\u7ec8\u7ed3\u679c\u538b\u7f29\u7387<\/p>\n<p><b>\u6d88\u8017\u56e0\u5b50\u5c5e\u6027\u53c2\u6570\uff1a<\/b><br \/>\n<u><i>\u53d8\u91cf\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u63cf\u8ff0<\/i><\/u><br \/>\ncHdfsReadCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u4eceHDFS\u8bfb\u6d88\u8017<br \/>\ncHdfsWriteCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u5199HDFS\u6d88\u8017<br \/>\ncLocalIOCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u4ece\u672c\u5730\u78c1\u76d8\u6267\u884cI\/O\u7684\u6d88\u8017<br \/>\ncNetworkCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u7f51\u7edc\u4f20\u8f93\u6d88\u8017<br \/>\ncMapCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u6267\u884cMAP\u51fd\u6570\u7684CPU\u6d88\u8017<br \/>\ncReduceCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u6267\u884cReduce\u51fd\u6570\u7684CPU\u6d88\u8017<br \/>\ncCombineCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u6267\u884cCombine\u51fd\u6570\u7684CPU\u6d88\u8017<br \/>\ncPartitionCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u5206\u533a\u7684CPU\u6d88\u8017<br \/>\ncSerdeCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u5e8f\u5217\u5316\u7684CPU\u6d88\u8017<br \/>\ncSortCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u6392\u5e8f\u7684CPU\u6d88\u8017<br \/>\ncMergeCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u5408\u5e76\u7684CPU\u6d88\u8017<br \/>\ncInUncomprCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u89e3\u538b\u8f93\u5165\u6570\u636e\u7684CPU\u6d88\u8017<br \/>\ncIntermUncomprCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0 \u89e3\u538b\u4e2d\u95f4\u6570\u636e\u7684CPU\u6d88\u8017<br \/>\ncIntermComprCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u538b\u7f29\u4e2d\u95f4\u7ed3\u679c\u7684CPU\u6d88\u8017<br \/>\ncOutComprCPUCost\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u538b\u7f29\u8f93\u51fa\u7ed3\u679c\u7684CPU\u6d88\u8017<\/p>\n<p>\u5b9a\u4e49\u6807\u8bb0\u51fd\u6570I\uff1a<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-155\" src=\"http:\/\/www.max-shu.com\/blog\/wp-content\/uploads\/2018\/03\/\u4e0b\u8f7d-5.png\" alt=\"\" width=\"904\" height=\"80\" \/><br \/>\n<b><br \/>\n\u521d\u59cb\u5316\uff1a<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-156\" src=\"http:\/\/www.max-shu.com\/blog\/wp-content\/uploads\/2018\/03\/\u4e0b\u8f7d-6.png\" alt=\"\" width=\"383\" height=\"574\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>MapReduce Job\u7684\u6267\u884c\u5206\u4e3amap\u4efb\u52a1\u548creduce\u4efb\u52a1\uff0cmap\u4efb\u52a1\u5206\u4e3a\u51e0\u4e2a\u9636\u6bb5\uff1aRead\uff08\u8bfbmap\u7684 &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[63],"tags":[80,123,122,120,121],"class_list":["post-154","post","type-post","status-publish","format-standard","hentry","category-63","tag-hadoop","tag-hdfs","tag-mapreduce","tag-120","tag-121"],"views":1767,"_links":{"self":[{"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/154","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=154"}],"version-history":[{"count":1,"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/154\/revisions"}],"predecessor-version":[{"id":157,"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/154\/revisions\/157"}],"wp:attachment":[{"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=154"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=154"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.max-shu.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=154"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}