在上一期我们对datax进行了技术调研 ,这一次我们集成一个RocketMQ写插件,能够非常方便对将mysql数据同步到MQ中,下面来总结下具体步骤。
1.下载datax源码,下载地址:
2.按照已有插件的代码结构建立rocketmqwriter的代码目录如下:
package.xml:定义了插件具体的打包路径
<assembly
xmlns="http:// maven .apache.org/plugins/maven-assembly-plugin/assembly/1.1.0"
xmlns:xsi="#34;
xsi:schemaLocation=" #34;>
<id></id>
<formats>
<format>dir</format>
</formats>
< include BaseDirectory> false </includeBaseDirectory>
<fileSets>
<fileSet>
<directory>src/main/resources</directory>
<includes>
<include>plugin.json</include>
</includes>
<outputDirectory>plugin/writer/ons-rocketmqwriter</outputDirectory>
</fileSet>
<fileSet>
<directory>target/</directory>
<includes>
<include>ons-rocketmqwriter-0.0.1-SNAPSHOT.jar</include>
</includes>
<outputDirectory>plugin/writer/ons-rocketmqwriter</outputDirectory>
</fileSet>
</fileSets>
<dependencySets>
<dependencySet>
<useProjectArtifact>false</useProjectArtifact>
<outputDirectory>plugin/writer/ons-rocketmqwriter/libs</outputDirectory>
<scope> runtime </scope>
</dependencySet>
</dependencySets>
</assembly>
- Key类:获取配置文件json传递的参数;
- MQColumn类:获取属性column[]的值;
- MQFieldType类:获取属性column[]值的类型;
- MQWriterErrorCode类:定义MQ解析过程中的异常错误码;
- ONS_RocketMQWriter类 :核心实现,数据解析以及MQ消息统一推送。
plugin.json:配置插件统一扫描文件实现类,即扫描ONS_RocketMQWriter类,配置如下:
{
"name": "ons-rocketmqwriter",
"class": "com.alibaba.datax.plugin.writer.ons_rocketmqwriter.ONS_RocketMQWriter",
"description": "适用于: 阿里云版RocketMQ",
"developer": "wenqi"
}
完成以上步骤,还需要修改Datax主工程配置文件package.xml,添加rocketmqwriter模块,代码如下:
<fileSet>
<directory>ons-rocketmqwriter/target/datax/</directory>
<includes>
<include>**/*.*</include>
</includes>
<outputDirectory>datax</outputDirectory>
</fileSet>
3.插件代码完成后,本地调试的话,需要修改core包下的Engine类,1)设置运行的datax的home目录;2)设置datax的 运行脚本 信息。截图如下:
4.本地调试完成后进行maven打包,在idea的terminal中执行 mvn -U clean package assembly:assembly -Dmaven.test.skip=true
5.编写json文件,mysql-mq.json
{
"job": {
"setting": {
"speed": {
"channel": 1,
"record": -1,
"byte": -1
}
},
"content": [{
"reader": {
"name": "mysqlreader",
"parameter": {
"username": "root",
"password": "******",
"connection": [
{
"querySql": [
"select id from table where id<7506000;"
],
"jdbcUrl": [
"jdbc:mysql://pc-xxx.rwlb.rds.aliyuncs.com:3306/db"
]
}
]
}
},
"writer": {
"name": "ons-rocketmqwriter",
"parameter": {
"nameServer": "#34;,
"accessKey": "xxxxxx",
"secretKey": "xxxxxx",
"topic": "topic_name",
"tags": "*",
"batchSize":1000,
"column": [
{"name": "tableId", "type": "string"}
]
}
}
}]
}
}
6.执行脚本命令便可以完成mysql数据按照规则同步给RocketMQ了
bin/datax.py job/mysql-mq.json
不断分享开发过程用到的技术和面试经常被问到的问题,如果您也对IT技术比较感兴趣可以「关注」我