熟悉常用的hdfs操作
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
|
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:
list scan ‘Student‘ alter ‘Student‘,NAME=>‘course‘ put ‘Student‘,‘3‘,‘course:Math‘,‘85’ dorp ‘Student‘,‘course‘ count ‘Student‘ truncate ‘Student‘
用mapreduce 处理气象数据集
编写程序求每日最高最低气温,区间最高最低气温
cd /usr/hadoop sodu mkdir qx cd /usr/hadoop/qx wget -D --accept-regex=REGEX -P data -r -c ftp://ftp.ncdc.noaa.gov/pub/data/noaa/2017/7* cd /usr/hadoop/qx/data/ftp.ncdc.noaa.gov/pub/data/noaa/2017 sudo zcat 7*.gz >qxdata.txt cd /usr/hadoop/qx
#!/usr/bin/env python import sys for i in sys.stdin: i = i.strip() d = i[15:23] t = i[87:92] print ‘%s\t%s‘ % (d,t)
#!/usr/bin/env python from operator import itemggetter import sys current_word = None current_count = 0 word = None for i in sys.stdin: i = i.strip() word,count = i.split(‘\t‘, 1) try: count = int(count) except ValueError: continue if current_word == word: if current_count > count: 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)
chmod a+x /usr/hadoop/qx/mapper.py chmod a+x /usr/hadoop/qx/reducer.py
通过hadoop上的hive完成WordCount
启动hadoop
Hdfs上创建文件夹
上传文件至hdfs
启动Hive
创建原始文档表
导入文件内容到表docs并查看
用HQL进行词频统计,结果放在表word_count里
查看统计结果
在这里:http://www.cnblogs.com/FZW1874402927/p/9085246.html
原文:https://www.cnblogs.com/FZW1874402927/p/9089123.html