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Apache MapReduce is a software framework for analyzing large amounts of data. It is provided by Apache Hadoop. MapReduce itself is beyond the scope of this document. A good place to start using MapReduce is https://hadoop.apache.org/docs/r2.6.0/hadoop-mapreduce-client/hadoop-mapreduce-client-core/MapReduceTutorial.html. MapReduce version 2 (MR2) is now part of YARN.
This chapter discusses the specific configuration steps that need to be taken when using MapReduce on data in HBase. In addition, it discusses other interactions and issues between HBase and MapReduce jobs. Finally, it discussed Cascading, another API of MapReduce.
mapred 和 mapreduce
There are two mapreduce packages in HBase, just like MapReduce itself: org.apache.hadoop.hbase.mapred and org.apache.hadoop.hbase.mapreduce. The former uses the old API and the latter uses the new model. The latter has more facilities, although you can usually find the same equipment in the old packaging. Select the software package to be used with the MapReduce deployment. If you have questions or start over, please select org.apache.hadoop.hbase.mapreduce. In the comments below, we refer to oahhmapreduce, but if this is what you are using, replace with oahhmapred.