关注码农话题
做一个实实在在的内行人

MapReduce – 编程

处理

  1. select:直接分析输入数据,取出需要的字段数据即可
  2. where: 也是对输入数据处理的过程中进行处理,判断是否需要该数据
  3. aggregation:min, max, sum
  4. group by: 通过Reducer实现
  5. sort
  6. join: map join, reduce join

Third-Party Libraries

export LIBJARS=$MYLIB/commons-lang-2.3.jar, hadoop jar prohadoop-0.0.1-SNAPSHOT.jar org.aspress.prohadoop.c3. WordCountUsingToolRunner -libjars $LIBJARS

hadoop jar prohadoop-0.0.1-SNAPSHOT-jar-with-dependencies.jar org.aspress.prohadoop.c3. WordCountUsingToolRunner The dependent libraries are now included inside the application JAR file

一般还是上面的好,指定依赖可以利用Public Cache,如果是包含依赖,则每次都需要拷贝。


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