1. 以下关系型数据库中的表和数据,要求将其转换为适合于HBase存储的表并插入数据:

学生表(Student)(不包括最后一列)

学号(S_No)

姓名(S_Name)

性别(S_Sex)

年龄(S_Age)

课程(course)

2015001

Zhangsan

male

23

 

2015003

Mary

female

22

 

2015003

Lisi

male

24

数学(Math)85

  

cd /usr/local/hadoop
./sbin/start-dfs.sh
cd /usr/local/hbase
./bin/start-hbase.sh
hbase shell

 

create 'Student',{NAME=>'S_No',VERSIONS=>5},{NAME=>'S_Name',VERSIONS=>5},{NAME=>'S_Sex',VERSIONS=>5},{NAME=>'S_Age',VERSIONS=>5}

put 'Student','2015001','sname','Zhangsan'
put 'Student','2015001','ssex','male'
put 'Student','2015001','sage','23'

put 'Student','2015002','sname','Mary'
put 'Student','2015002','ssex','female'
put 'Student','2015002','sage','22'

put 'Student','2015003','sname','Lisi'
put 'Student','2015003','ssex','male'
put 'Student','2015003','sage','24

 

2. 用Hadoop提供的HBase Shell命令完成相同任务:

  • 列出HBase所有的表的相关信息;list
    list
    TABLE
    Student

     

  • 在终端打印出学生表的所有记录数据;
    scan 'Student'

     

  • 向学生表添加课程列族;
    alter 'Student','NAME'=>'course'

     

  • 向课程列族添加数学列并登记成绩为85;
    put 'Student','2015003','course:Math','85'

     

  • 删除课程列;
    alter 'Student','NAME'=>'course','METHOD'=>'delete'

     

  • 统计表的行数;count 's1'
    count 'Student'

     

  • 清空指定的表的所有记录数据;truncate 's1'
    truncate 'Student'

     

 

3. 用Python编写WordCount程序任务

程序

WordCount

输入

一个包含大量单词的文本文件

输出

文件中每个单词及其出现次数(频数),并按照单词字母顺序排序,每个单词和其频数占一行,单词和频数之间有间隔

  1. 编写map函数,reduce函数
  2. 将其权限作出相应修改
  3. 本机上测试运行代码
  4. 放到HDFS上运行
  5. 下载并上传文件到hdfs上
  6. 用Hadoop Streaming命令提交任务

  创建mapper.py文件:

cd /home/hadoop/wc
sudo gedit mapper.py

map函数

#!/usr/bin/env python
import sys
for i in stdin:
    i = i.strip()
    words = i.split()
    for word in words:
    print '%s\t%s' % (word,1)

 赋予权限

chmod a+x /home/hadoop/mapper.py

创建reducer.py文件

cd /home/hadoop/wc
sudo gedit reducer.py

reduce函数

#!/usr/bin/env python
from operator import itemgetter
import sys

current_word = None
current_count = 0
word = None

for i in stdin:
    i = i.strip()
    word, count = i.split('\t',1)
    try:
    count = int(count)
    except ValueError:
    continue

    if current_word == word:
    current_count += count 
    else:
    if current_word:
        print '%s\t%s' % (current_word, current_count)
    current_count = count
    current_word = word

if current_word == word:
    print '%s\t%s' % (current_word, current_count)

赋予权限

chmod a+x /home/hadoop/reduce.py

测试代码

echo "foo foo quux labs foo bar quux" | /home/hadoop/wc/mapper.py

echo "foo foo quux labs foo bar quux" | /home/hadoop/wc/mapper.py | sort -k1,1 | /home/hadoop/wc/reducer.p

 下载文件上传

cd  /home/hadoop/wc
wget http://www.gutenberg.org/files/5000/5000-8.txt
wget http://www.gutenberg.org/cache/epub/20417/pg20417.txt
cd /usr/hadoop/wc
hdfs dfs -put /home/hadoop/hadoop/gutenberg/*.txt /user/hadoop/input
 

用Hadoop Streaming命令提交任务

gedit run.sh

 

posted on 2018-05-08 21:42  189黄思慧  阅读(114)  评论(0编辑  收藏  举报