摘要: Apache Hadoop NextGen MapReduce (YARN)MapReduce has undergone a complete overhaul in hadoop-0.23 and we now have, what we call, MapReduce 2.0 (MRv2) o... 阅读全文
posted @ 2015-01-06 22:21 凝静志远 阅读(231) 评论(0) 推荐(0) 编辑
摘要: hadoop版本:1.1.2一、Mapper类的结构Mapper类是Job.setInputFormatClass()方法的默认值,Mapper类将输入的键值对原封不动地输出。org.apache.hadoop.mapreduce.Mapper类的结构如下:public class Mapper {... 阅读全文
posted @ 2015-01-06 22:01 凝静志远 阅读(379) 评论(0) 推荐(0) 编辑
摘要: NameNode类位于org.apache.hadoop.hdfs.server.namenode包下。NameNode serves as both directory namespace manager and "inode table" for the Hadoop DFS. There is... 阅读全文
posted @ 2015-01-06 21:55 凝静志远 阅读(270) 评论(0) 推荐(0) 编辑