在線練習(xí)
http://cloudcomputing.ruc.edu.cn
處理
- select:直接分析輸入數(shù)據(jù),取出需要的字段數(shù)據(jù)即可
- where: 也是對(duì)輸入數(shù)據(jù)處理的過程中進(jìn)行處理,判斷是否需要該數(shù)據(jù)
- aggregation:min, max, sum
- group by: 通過Reducer實(shí)現(xiàn)
- sort
- 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
一般還是上面的好,指定依賴可以利用Public Cache,如果是包含依賴,則每次都需要拷貝
參考書籍
MapReduce Design Patterns