简介：

Apache Sqoop 是一种用于 Apache Hadoop 与关系型数据库之间结构化、非结构化数据转换的工具。

一、安装 MySQL、导入测试数据

2、导入测试数据

mysql > create databasetmpdb;

mysql> usetmpdb;

mysql>system ls

tmp_recommend_hot.sql

mysql> source tmp_recommend_hot.sql

# 创建测试库，导入测试表

3、授权 hadoop

mysql > grant all on *.* to hadoop@'%' identified by 'hadoop';

mysql> flush privileges;

二、安装 Sqoop

1、下载、解压、设置环境变量

shell > cd /usr/local/src

shell> wget http://apache.fayea.com/sqoop/1.4.6/sqoop-1.4.6.bin__hadoop-2.0.4-alpha.tar.gz

shell > tar zxf sqoop-1.4.6.bin__hadoop-2.0.4-alpha.tar.gz -C ../shell> cd /usr/local/sqoop-1.4.6.bin__hadoop-2.0.4-alpha

shell> vim /etc/profile

export PATH=$PATH:/usr/local/mysql/bin:/usr/local/hadoop-2.8.0/bin:/usr/local/apache-hive-2.1.1-bin/bin:/usr/local/sqoop-1.4.6.bin__hadoop-2.0.4-alpha/bin

shell> source /etc/profile

2、修改 sqoop-env.sh

shell > cp conf/sqoop-env-template.sh conf/sqoop-env.shshell> vim conf/sqoop-env.sh# 指定安装目录

export HADOOP_COMMON_HOME=/usr/local/hadoop-2.8.0export HADOOP_MAPRED_HOME=/usr/local/hadoop-2.8.0

3、复制 MySQL 连接器

shell > cp /usr/local/src/mysql-connector-java-5.1.41/mysql-connector-java-5.1.41-bin.jar lib/

4、测试

shell > sqoop list-databases --connect jdbc:mysql://master.hadoop:3306 \

> --username hadoop --password hadoop

information_schema

hive_meta

mysql

performance_schema

test

tmpdb

# 连接成功

三、MySQL To HDFS To Hive

1、创建数据存放目录

hadoop shell > hdfs dfs -mkdir /user/root

hadoop shell> hdfs dfs -chown root /user/root

2、将数据导入 HDFS

shell > sqoop import --connect jdbc:mysql://master.hadoop:3306/tmpdb \

> --username hadoop --password hadoop \> --table tmp_recommend_hot --warehouse-dir=/user/root

hadoop shell> hdfs dfs -ls /user/root

Found1items

drwxr-xr-x - root supergroup 0 2017-05-26 18:47 /user/root/tmp_recommend_hot

hadoop shell> hdfs dfs -ls /user/root/tmp_recommend_hot

Found5items-rw-r--r-- 3 root supergroup 0 2017-05-26 18:47 /user/root/tmp_recommend_hot/_SUCCESS-rw-r--r-- 3 root supergroup 17426 2017-05-26 18:47 /user/root/tmp_recommend_hot/part-m-00000

-rw-r--r-- 3 root supergroup 18188 2017-05-26 18:47 /user/root/tmp_recommend_hot/part-m-00001

-rw-r--r-- 3 root supergroup 18719 2017-05-26 18:47 /user/root/tmp_recommend_hot/part-m-00002

-rw-r--r-- 3 root supergroup 18430 2017-05-26 18:47 /user/root/tmp_recommend_hot/part-m-00003

# 默认情况下启用 4 个 MR 进程，所以有 4 个文件

3、将数据从 HDFS 导入 Hive

shell > beeline -u jdbc:hive2://master.hadoop:10000 -n hadoop

0: jdbc:hive2://master.hadoop:10000> create database tmpdb;

0: jdbc:hive2://master.hadoop:10000> use tmpdb;

0: jdbc:hive2://master.hadoop:10000> dfs -cat /user/root/tmp_recommend_hot/*;

+--------------------------------------------------------------------------------------------------------------------------------+--+

| 401,1859110,资讯,2017,《人民的名义》热播原著小说杭州卖断货,http://pic2.qiyipic.com/image/20170410/0f/2a/v_112112674_m_601.jpg,934,null |

| 402,1859123,资讯,2017,临汾旅游景区体制机制改革再出招,http://pic6.qiyipic.com/image/20170410/a5/bb/v_112112690_m_601.jpg,420,null |

| 403,1291853,电影,2016,魔兽,http://imgbftv.b0.upaiyun.com/upload/origin/8/147598326883101.jpg,326,null |

| 404,1838847,综艺,2017,奇葩说第4季,http://imgbftv.b0.upaiyun.com/upload/origin/2/149176084218704.jpg,579,null |

| 405,14614,电视剧,2014,神雕侠侣,http://imgbftv.b0.upaiyun.com/upload/origin/6/143945924668370.jpg,260,null |

| 406,387443,电影,2005,金刚2005,http://imgbftv.b0.upaiyun.com/upload/origin/3/148497964349088.jpg,2563,null |

| 407,1861695,资讯,2017,追踪：夜半横躺马路中央男子遭碾压致死,http://pic6.qiyipic.com/image/20170411/3e/66/v_112119228_m_601.jpg,806,null |

| 408,1841442,综艺,2017,天生是优我,http://imgbftv.b0.upaiyun.com/upload/origin/1/149182951136923.jpg,1094,null

# 查看了一下原始数据，是以 , 为分隔符的文本

0: jdbc:hive2://master.hadoop:10000> create external table hot_film

. . . . . . . . . . . . . . . . . .> (id int, vid int, type string, year int, name string, image string, views int, dtime int)

. . . . . . . . . . . . . . . . . .> row format delimited fields terminated by ','. . . . . . . . . . . . . . . . . .> location 'hdfs:///user/root/tmp_recommend_hot';

# 创建了一个外部表，/user/hive/warehouse/tmpdb.db 下并没有数据，数据还存在原始位置 /user/root/tmp_recommend_hot 下

0: jdbc:hive2://master.hadoop:10000> select id, vid, name, views from hot_film limit 3;

+-----+----------+-----------+--------+--+

| id | vid | name | views |

+-----+----------+-----------+--------+--+

| 1 | 1544131 | 三生三世十里桃花 | 1003 |

| 2 | 1774150 | 情圣 | 630 |

| 3 | 1774815 | 因为遇见你 | 548 |

+-----+----------+-----------+--------+--+

# 数据没问题，经 count(id) 对比，数据也没少！

四、MySQL To Hive

1、创建 Hive 数据库

shell > beeline -u jdbc:hive2://master.hadoop:10000 -n hadoop

0: jdbc:hive2://master.hadoop:10000> create database tmpdb2;

2、导入数据

shell > sqoop import --connect jdbc:mysql://master.hadoop:3306/tmpdb \

> --username hadoop --password hadoop \> --fields-terminated-by '\t' --table tmp_recommend_hot \> --hive-import --hive-database tmpdb2 --hive-table hot_film

# import、import-all-tables 导入表、导入所有表

# --fields-terminated-by 指定分隔符

# --table 指定导入的表

# --hive-import 导入 hive 表

# --hive-database 指定导入到 hive 哪个数据库中

# --hive-table 指定导入后的表名，不指定时保持原表名

# --hive-overwrite 覆盖写入

# -m 指定启动几个 map/reduce 程序，表中没有主键时，需要指定 -m 1

3、验证数据

0: jdbc:hive2://master.hadoop:10000> use tmpdb2;

0: jdbc:hive2://master.hadoop:10000> show tables;

+-----------+--+

| tab_name |

+-----------+--+

| hot_film |

+-----------+--+

0: jdbc:hive2://master.hadoop:10000> select id, vid, name, views from hot_film limit 3;

+-----+----------+-----------+--------+--+

| id | vid | name | views |

+-----+----------+-----------+--------+--+

| 1 | 1544131 | 三生三世十里桃花 | 1003 |

| 2 | 1774150 | 情圣 | 630 |

| 3 | 1774815 | 因为遇见你 | 548 |

+-----+----------+-----------+--------+--+

# 一切正常，这样导入的是内部表，数据会被移动到 hive 配置文件中指定的路径。默认 /user/hive/warehouse

报错管理：

1、数据文件已存在

17/05/27 14:34:15ERROR tool.ImportTool: Encountered IOException running import job: org.apache.hadoop.mapred.FileAlreadyExistsException:

Output directory hdfs://master.hadoop:8020/user/root/tmp_recommend_hot already exists

# 与上一个实验导入的数据冲突，从 hdfs 删除即可，当然上个实验的数据库表中就没有数据了

2、权限不足

17/05/27 14:48:34 INFO hive.HiveImport: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. MetaException(message:Got exception: org.apache.hadoop.security.AccessControlException Permission denied: user=root, access=WRITE, inode="/user/hive/warehouse/tmpdb2.db":hadoop:supergroup:drwxrwxr-x

# 开放 /user/hive 目录权限，hdfs dfs -chmod -R 777 /user/hive