Recompile DataX to support MySQL8.0

Problem Description:

When using DataX to migrate MySQL 8.0, a connection failure is reported:

RetryUtil - Exception when calling callable, 即将尝试执行第1次重试.本次重试计划等待[1000]ms,实际等待[1000]ms, 
异常Msg:[Code:[DBUtilErrorCode-10], Description:[连接数据库失败. 请检查您的 账号、密码、数据库名称、IP、Port或者向 DBA 寻求帮助(注意网络环境).].  -  
具体错误信息为：com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.

Cause Analysis:

According to the last line of the exception log, com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.]it can be determined that the root problem is caused by the MySQL driver not supporting it.
By looking at the lib folder of the mysql plug-in mysqlwriter/mysqlreader, we can see that DataX is currently using the mysql driver mysql-connector-java-5.1.34.jar, which does not support mysql8 connections.

solution:

Change the mysql driver version, modify some codes, and reload DataX

1. Download the DataX source code. Get the source code
   by git cloneor downloading datax-master.zip directly.
2. Change the plug-in's pom dependency and upgrade the mysql driver.
   Since I only use the mysqlwriter plug-in here, I only modify the pom.xml of the reading plug-in.
   vi DataX-master\mysqlwriter\pom.xml

		<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.19</version>
        </dependency>

By viewing the source code, MysqlWriter.java was introduced com.alibaba.datax.plugin.rdbms.util.DataBaseType, so the DataBaseType needs to be modified.

3. Modify the pom.xml of rdbms and upgrade the MySQL driver
   vi DataX-master\plugin-rdbms-util\pom.xml

		<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.19</version>
        </dependency>

4. Modify DataBaseType.javathe source code.
   There are two modifications involved here.
   One is to com.mysql.jdbc.Driverchange it to com.mysql.cj.jdbc.Driver; the other is to change
   the connection attribute to ;zeroDateTimeBehavior=convertToNull
zeroDateTimeBehavior=CONVERT_TO_NULL

vi DataX-master\plugin-rdbms-util\src\main\java\com\alibaba\datax\plugin\rdbms\util

5. maven recompile DataX

cd DataX-master
mvn -U clean package assembly:assembly -Dmaven.test.skip=true

6. Copying the recompiled plug-in to DataX
   mainly involves copying three jar packages:

$ cd DataX-master\mysqlwriter\target\datax\plugin\writer\mysqlwriter\libs
$ ls 
mysql-connector-java-8.0.19.jar
plugin-rdbms-util-0.0.1-SNAPSHOT.jar

Copy the above two jar packages to the originally installed DataX directory /datax/plugin/writer/mysqlwriter/libs.

$ cd DataX-master\mysqlwriter\target\datax\plugin\writer\mysqlwriter
$ ls 
mysqlwriter-0.0.1-SNAPSHOT.jar

Copy the above jar package to /datax/plugin/writer/mysqlwriterthe directory where DataX was originally installed.

7. Verify:
   Write a mysqljob task and execute it