Alex 的 Hadoop 菜鸟教程: 第7课 Sqoop2 导入教程

Alex 的 Hadoop 菜鸟教程: 第7课 Sqoop2 导入教程

时间 2014-11-26 17:13:36 CSDN博客

原文  http://blog.csdn.net/nsrainbow/article/details/41518451

主题 数据库 Hadoop HDFS

具体的安装和jdbc的驱动准备你们看第6课。现在我用一个例子讲解sqoop2的具体使用方法

数据准备

有一个mysql的表叫worker，里面有三条数据，我们要将其导入hadoop

这是建表语句

CREATE TABLE `workers` (  
  `id` int(11) NOT NULL AUTO_INCREMENT,  
  `name` varchar(20) NOT NULL,  
  PRIMARY KEY (`id`)  
) ENGINE=MyISAM  DEFAULT CHARSET=utf8;

插入三条数据

insert into workers (name) values ('jack');
insert into workers (name) values ('vicky');
insert into workers (name) values ('martin');

接下来我们使用sqoop客户端进行导入工作

导入数据

建立数据库连接

$ sqoop2
Sqoop home directory: /usr/lib/sqoop2
Sqoop Shell: Type 'help' or '\h' for help.

sqoop:000> create connection --cid 1

这句话的意思是建立一个id为1的连接，然后sqoop会让你输入一些必要参数

Creating connection for connector with id 1
Please fill following values to create new connection object
Name: First connection

Configuration configuration
JDBC Driver Class: com.mysql.jdbc.Driver
JDBC Connection String: jdbc:mysql://mysql.server/database
Username: sqoop
Password: *****
JDBC Connection Properties:
There are currently 0 values in the map:
entry#

Security related configuration options
Max connections: 0
New connection was successfully created with validation status FINE and persistent id 1

记得把  jdbc:mysql://mysql.server/database  替换成你真实的数据库连接

建立job

建立一个id为1的job，类型是 import

sqoop:000> create job --xid 1 --type import

接下来sqoop会让你输入需要的参数，只需要输入job的名字和Table name就好了，还有几个存储选项都选0，其他直接回车

Creating job for connection with id 1
Please fill following values to create new job object
Name: First job

Database configuration
Table name: workers
Table SQL statement:
Table column names:
Partition column name:
Boundary query:

Output configuration
Storage type:
  0 : HDFS
Choose: 0
Output format: 
  0 : TEXT_FILE
  1 : SEQUENCE_FILE
Choose: 0
Compression format: 
  0 : NONE
  1 : DEFAULT
  2 : DEFLATE
  3 : GZIP
  4 : BZIP2
  5 : LZO
  6 : LZ4
  7 : SNAPPY
Choose: 0
Output directory: /user/jarcec/users
New job was successfully created with validation status FINE and persistent id 1

执行任务

用start job命令去执行这个任务，用--jid来传入任务id

sqoop:000> start job --jid 1
Submission details
Job ID: 1
Server URL: http://localhost:12000/sqoop/
Created by: root
Creation date: 2014-11-26 16:41:30 CST
Lastly updated by: root
External ID: job_1406097234796_0006
	N/A
2014-11-26 16:41:30 CST: BOOTING  - Progress is not available

检查结果

再打开一个ssh终端，然后用hdfs的命令查看结果

$ hdfs dfs -ls /user/jarcec/workers/
Found 3 items
-rw-r--r--   2 sqoop2 supergroup          0 2014-11-26 16:42 /user/jarcec/workers/_SUCCESS
-rw-r--r--   2 sqoop2 supergroup          9 2014-11-26 16:41 /user/jarcec/workers/part-m-00000
-rw-r--r--   2 sqoop2 supergroup         21 2014-11-26 16:42 /user/jarcec/workers/part-m-00001

可以看到有三个结果文件被生成，然后我们cat看下文件的内容

$ hdfs dfs -cat /user/jarcec/workers/part-m-00000
1,'jack'
$ hdfs dfs -cat /user/jarcec/workers/part-m-00001
2,'vicky'
3,'martin'

今天写到这里，下节课讲讲导出