DataX 实战案例 -- 使用datax实现将hdfs数据导入到mysql表中

需求: 将hdfs上数据文件 user.txt 导入到mysql数据库的user表中。

1、创建作业的配置文件（json格式）

查看配置模板，执行脚本命令

[hadoop@hadoop03 ~]$ cd /bigdata/install/datax
[hadoop@hadoop03 datax]$ python bin/datax.py -r hdfsreader -w mysqlwriter

DataX (DATAX-OPENSOURCE-3.0), From Alibaba !
Copyright (C) 2010-2017, Alibaba Group. All Rights Reserved.

Please refer to the hdfsreader document:
     https://github.com/alibaba/DataX/blob/master/hdfsreader/doc/hdfsreader.md 

Please refer to the mysqlwriter document:
     https://github.com/alibaba/DataX/blob/master/mysqlwriter/doc/mysqlwriter.md 
 
Please save the following configuration as a json file and  use
     python {DATAX_HOME}/bin/datax.py {JSON_FILE_NAME}.json 
to run the job.

{
    "job": {
        "content": [
            {
                "reader": {
                    "name": "hdfsreader", 
                    "parameter": {
                    "column": [], 
                    "defaultFS": "", 
                        "encoding": "UTF-8", 
                        "fieldDelimiter": ",", 
                        "fileType": "orc", 
                        "path": ""
                    }
                }, 
                "writer": {
                    "name": "mysqlwriter", 
                    "parameter": {
                        "column": [], 
                        "connection": [
                            {
                                "jdbcUrl": "", 
                                "table": []
                            }
                        ], 
                        "password": "", 
                        "preSql": [], 
                        "session": [], 
                        "username": "", 
                        "writeMode": ""
                    }
                }
            }
        ], 
        "setting": {
            "speed": {
                "channel": ""
            }
        }
    }
}

其中hdfsreader插件文档
- https://github.com/alibaba/DataX/blob/master/hdfsreader/doc/hdfsreader.md

2、根据模板写配置文件

进入到 /bigdata/install/datax/job 目录，然后创建配置文件 hdfs2mysql.json, 文件内容如下：

{
    "job": {
        "setting": {
            "speed": {
                 "channel":1
            }
        },
        "content": [
            {
                "reader": {
                    "name": "hdfsreader",
                    "parameter": {
                    "defaultFS": "hdfs://hadoop01:8020",
                        "path": "/user.txt",                  
                        "fileType": "text",
                        "encoding": "UTF-8",
                        "fieldDelimiter": "\t",
                        "column": [
                               {
                                "index": 0,
                                "type": "long"
                               },
                               {
                                "index": 1,
                                "type": "string"
                               },
                               {
                                "index": 2,
                                "type": "long"
                               }
                        ]
                      }
                  },
               "writer": {
                    "name": "mysqlwriter",
                    "parameter": {
                        "writeMode": "insert",
                        "username": "root",
                        "password": "123456",
                        "column": [
                            "id",
                            "name",
                            "age"
                        ],
                        "preSql": [
                            "delete from user"
                        ],
                        "connection": [
                            {
                                "jdbcUrl": "jdbc:mysql://hadoop02:3306/datax?useUnicode=true&characterEncoding=utf-8",
                                "table": [
                                    "user"
                                ]
                            }
                        ]
                    }
                }
            }
        ]
    }
}

3、准备HDFS上测试数据文件 user.txt
- user.txt文件内容如下
```
1	zhangsan  20
2	lisi  29
3	wangwu  25
4	zhaoliu  35
5	kobe  40
```
- 文件中每列字段通过\t 制表符进行分割，上传文件到hdfs上
```
[hadoop@hadoop03 ~]$ hdfs dfs -put user.txt /
```

4、创建目标表

mysql> create table datax.user(id int,name varchar(20),age int);

5、启动DataX

[hadoop@hadoop03 ~]$ cd /bigdata/install/datax
[hadoop@hadoop03 bin]$ python bin/datax.py job/hdfs2mysql.json

6、观察控制台输出结果

同步结束，显示日志如下：

任务启动时刻                    : 2021-06-18 12:02:47
任务结束时刻                    : 2021-06-18 12:02:58
任务总计耗时                    :                 11s
任务平均流量                    :                4B/s
记录写入速度                    :              0rec/s
读出记录总数                    :                   5
读写失败总数                    :                   0

7、查看user表数据

DataX 实战案例 -- 使用datax实现将hdfs数据导入到mysql表中

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