37、Flink 的CDC 格式：debezium部署以及mysql示例（1）-debezium的部署与示例

Flink 系列文章

一、Flink 专栏

Flink 专栏系统介绍某一知识点，并辅以具体的示例进行说明。

1、Flink 部署系列本部分介绍Flink的部署、配置相关基础内容。
2、Flink基础系列本部分介绍Flink 的基础部分，比如术语、架构、编程模型、编程指南、基本的datastream api用法、四大基石等内容。
3、Flik Table API和SQL基础系列本部分介绍Flink Table Api和SQL的基本用法，比如Table API和SQL创建库、表用法、查询、窗口函数、catalog等等内容。
4、Flik Table API和SQL提高与应用系列本部分是table api 和sql的应用部分，和实际的生产应用联系更为密切，以及有一定开发难度的内容。
5、Flink 监控系列本部分和实际的运维、监控工作相关。

二、Flink 示例专栏

Flink 示例专栏是 Flink 专栏的辅助说明，一般不会介绍知识点的信息，更多的是提供一个一个可以具体使用的示例。本专栏不再分目录，通过链接即可看出介绍的内容。

两专栏的所有文章入口点击：Flink 系列文章汇总索引

文章目录

本文详细的介绍了debezium的部署、验证以及通过一个示例介绍其使用。

如果需要了解更多内容，可以在本人Flink 专栏中了解更新系统的内容。

本文除了maven依赖外，还依赖kafka、flink、debezium。

本专题文章分为如下几篇：

37、Flink 的CDC 格式：debezium部署以及mysql示例（1）-debezium的部署与示例
37、Flink 的CDC 格式：debezium部署以及mysql示例（2）-Flink 与Debezium 实践
37、Flink 的CDC 格式：debezium部署以及mysql示例（完整版）

一、Debezium Format

1、Debezium介绍

Debezium 是一个 CDC（Changelog Data Capture，变更数据捕获）的工具，可以把来自 MySQL、PostgreSQL、Oracle、Microsoft SQL Server 和许多其他数据库的更改实时流式传输到 Kafka 中。 Debezium 为变更日志提供了统一的格式结构，并支持使用 JSON 和 Apache Avro 序列化消息。

Flink 支持将 Debezium JSON 和 Avro 消息解析为 INSERT / UPDATE / DELETE 消息到 Flink SQL 系统中。在很多情况下，利用这个特性非常的有用，例如

将增量数据从数据库同步到其他系统
日志审计
数据库的实时物化视图
关联维度数据库的变更历史，等等。

Flink 还支持将 Flink SQL 中的 INSERT / UPDATE / DELETE 消息编码为 Debezium 格式的 JSON 或 Avro 消息，输出到 Kafka 等存储中。但需要注意的是，目前 Flink 还不支持将 UPDATE_BEFORE 和 UPDATE_AFTER 合并为一条 UPDATE 消息。因此，Flink 将 UPDATE_BEFORE 和 UPDATE_AFTER 分别编码为 DELETE 和 INSERT 类型的 Debezium 消息。

2、binlog设置及验证

设置binlog需要监控的数据库，本示例使用的数据库是mysql5.7

1）、配置

本示例设置的参数参考下面的配置

[root@server4 ~]# cat /etc/my.cnf# For advice on how to change settings please see# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html[mysqld]......

log-bin=mysql-bin  # log-bin的名称，可以是任意名称
binlog-format=row  # 推荐该参数，其他的参数视情况而定，比如mixed、statementserver_id=1# mysql集群环境中不要重复binlog_do_db=test # test是mysql的数据库名称，如果监控多个数据库，可以添加多个binlog_do_db即可，例如下面示例# binlog_do_db=test2# binlog_do_db=test3.....

STATEMENT模式（SBR）每一条会修改数据的sql语句会记录到binlog中。优点是并不需要记录每一条sql语句和每一行的数据变化，减少了binlog日志量，节约IO，提高性能。缺点是在某些情况下会导致master-slave中的数据不一致(如sleep()函数， last_insert_id()，以及user-defined functions(udf)等会出现问题)
ROW模式（RBR）不记录每条sql语句的上下文信息，仅需记录哪条数据被修改了，修改成什么样了。而且不会出现某些特定情况下的存储过程、或function、或trigger的调用和触发无法被正确复制的问题。缺点是会产生大量的日志，尤其是alter table的时候会让日志暴涨。
MIXED模式（MBR）以上两种模式的混合使用，一般的复制使用STATEMENT模式保存binlog，对于STATEMENT模式无法复制的操作使用ROW模式保存binlog，MySQL会根据执行的SQL语句选择日志保存方式。

2）、重启mysql

保存配置后重启mysql

service mysqld restart

3）、验证

重启后，可以通过2个简单的方法验证是否设置成功。

mysql默认的安装目录：cd /var/lib/mysql

[root@server4 ~]# cd /var/lib/mysql[root@server4 mysql]# ll......
-rw-r----- 1 mysql mysql    1541月  102022 mysql-bin.000001
-rw-r----- 1 mysql mysql       11971月  1612:21 mysql-bin.index
.....

查看mysql-bin.000001文件是否生成，且其大小为154字节。mysql-bin.000001是mysql重启的次数，重启2次则为mysql-bin.000002
在test数据库中创建或添加数据，mysql-bin.000001的大小是否增加

以上情况满足，则说明binlog配置正常

3、debezium部署及验证

1）、下载-mysql connector连接器

去其官网：https://debezium.io/releases/下载需要的版本。
本示例使用的是：debezium-connector-mysql-1.7.2.Final-plugin.tar.gz

2）、解压

创建解压目录：/usr/local/bigdata/debezium/connector
解压

tar zxvf /usr/local/bigdata/debezium-connector-mysql-1.7.2.Final-plugin.tar.gz -C /usr/local/bigdata/debezium/connector
## 解压后[alanchan@server3 connector]$ ll
总用量 4
drwxr-xr-x 2 alanchan root 40961月  16 07:20 debezium-connector-mysql
[alanchan@server3 connector]$ cd debezium-connector-mysql/
[alanchan@server3 debezium-connector-mysql]$ ll
总用量 10312
-rw-rw-r-- 1 alanchan root  33786412月 142021 antlr4-runtime-4.8.jar
-rw-rw-r-- 1 alanchan root  30896612月 142021 CHANGELOG.md
-rw-rw-r-- 1 alanchan root   1922812月 142021 CONTRIBUTE.md
-rw-rw-r-- 1 alanchan root    498112月 142021 COPYRIGHT.txt
-rw-rw-r-- 1 alanchan root   2068212月 142021 debezium-api-1.7.2.Final.jar
-rw-rw-r-- 1 alanchan root  40054612月 142021 debezium-connector-mysql-1.7.2.Final.jar
-rw-rw-r-- 1 alanchan root  88636312月 142021 debezium-core-1.7.2.Final.jar
-rw-rw-r-- 1 alanchan root 282543012月 142021 debezium-ddl-parser-1.7.2.Final.jar
-rw-rw-r-- 1 alanchan root    461712月 142021 failureaccess-1.0.1.jar
-rw-rw-r-- 1 alanchan root 285842612月 142021 guava-30.0-jre.jar
-rw-rw-r-- 1 alanchan root  12915712月 142021 LICENSE-3rd-PARTIES.txt
-rw-rw-r-- 1 alanchan root   1135712月 142021 LICENSE.txt
-rw-rw-r-- 1 alanchan root  19338612月 142021 mysql-binlog-connector-java-0.25.3.jar
-rw-rw-r-- 1 alanchan root 247508712月 142021 mysql-connector-java-8.0.27.jar
-rw-rw-r-- 1 alanchan root   1952012月 142021 README_JA.md
-rw-rw-r-- 1 alanchan root   1528612月 142021 README.md
-rw-rw-r-- 1 alanchan root   1311412月 142021 README_ZH.md

3）、kafka配置

因为配置的是kafka的插件，所以需要修改kafka的插件配置，同时需要注意的是，debezium的安装目录需要kafka能找到。
本示例中kafka的安装目录：/usr/local/bigdata/kafka_2.12-3.0.0

修改kafka插件配置文件connect-distributed.properties 修改内容如下，其他的根据情况进行配置，否则就是默认的

bootstrap.servers=server1:9092,server2:9092,server3:9092
group.id=connect-cluster
status.storage.replication.factor=2

plugin.path=/usr/local/bigdata/debezium/connector

根据实际的应用环境决定是否分发该配置文件

重启kafka集群

4）、启动kafak的插件

需要在部署debezium的机器上进行此操作

#在kafka的/usr/local/bigdata/kafka_2.12-3.0.0/bin目录下启动#执行命令：
connect-distributed.sh -daemon /usr/local/bigdata/kafka_2.12-3.0.0/config/connect-distributed.properties

[alanchan@server3 config]$ cd /usr/local/bigdata/kafka_2.12-3.0.0/bin
[alanchan@server3 bin]$ connect-distributed.sh -daemon /usr/local/bigdata/kafka_2.12-3.0.0/config/connect-distributed.properties
[alanchan@server3 bin]$ jps
8980 ConnectDistributed
9271 Jps
826 Kafka
# ConnectDistributed 进程名称即为kafka插件# 也可以通过下面的方式验证[alanchan@server3 bin]$ curl server3:8083
{"version":"3.0.0","commit":"8cb0a5e9d3441962","kafka_cluster_id":"dVRZjBtQQnum1bb7pu_ljg"}# 也可以查看有哪些连接器在工作，由于当前还未注册任何的连接器，故为空[alanchan@server3 bin]$ curl192.168.10.43:8083/connectors/
[]

5）、注册mysql的连接器

参数说明

{"name":"alan-debezium-mysql-connector", // 向 Kafka Connect 服务注册时的连接器名称。
    "config":{"connector.class":"io.debezium.connector.mysql.MySqlConnector", // 连接器的类名，不能修改。
        "database.hostname":"192.168.10.44", //MySQL 服务器地址
        "database.port":"3306", // MySQL 服务器端口号
        "database.user":"root", // 具有适当权限的 MySQL 用户
        "database.password":"123456", // MySQL 用户的密码
        "database.server.id":"184054", // 连接器的唯一 ID，随便写，但不应该重复
        "database.server.name":"ALAN", // MySQL 服务器或集群的逻辑名称，将来作为kafka的topic前缀
        "database.include.list":"cdctest", // 指定服务器托管的数据库列表，多个数据库可以用逗号分隔
        "database.history.kafka.bootstrap.servers":"server1:9092,server2:9092,server3:9092", // 连接器用于将 DDL 语句写入和恢复到数据库历史主题的 Kafka 代理列表
        "database.history.kafka.topic":"alan.historydb", // 数据库历史主题的名称。本主题仅供内部使用，消费者不得使用
        "include.schema.changes":"true" // 指定连接器是否应为 DDL 更改生成事件并将它们发送到fulfillment架构更改主题以供使用者使用的标志
    }}

命令行执行

curl -i -X POST -H "Accept:application/json" -H "Content-Type:application/json"192.168.10.43:8083/connectors/ -d {"name":"alan-debezium-mysql-connector","config":{"connector.class":"io.debezium.connector.mysql.MySqlConnector","database.hostname":"192.168.10.44","database.port":"3306","database.user":"root","database.password":"123456","database.server.id":"184054", "database.server.name":"ALAN", "database.include.list":"cdctest", "database.history.kafka.bootstrap.servers":"server1:9092,server2:9092,server3:9092", "database.history.kafka.topic":"alan.historydb","include.schema.changes":"true"}}

postman等工具执行执行后，返回也可以在kafka的可视化工具中查看，比如offset explorer 也可以通过命令行查看是否注册成功

[alanchan@server3 bin]$ curl192.168.10.43:8083/connectors/
["alan-debezium-mysql-connector"]

6）、数据验证

启动成功后，debezium会将监控的数据库表中的数据同步到kafka的消息队列中。
本示例中，mysql中的原始数据如下
在这里插入图片描述

启动插件成功后，kafka对应的topic中的数据如下
在这里插入图片描述

以上，则表示完成debezium的初步验证成功。

4、示例：通过Debezium CDC 将mysql数据变化输出至kafka

以下是针对表userscoressink新增、修改和删除的数据后kafka主题ALAN.cdctest.userscoressink的变化情况

[alanchan@server1 bin]$ kafka-console-consumer.sh --bootstrap-server server1:9092 --topic ALAN.cdctest.userscoressink --from-beginning
......{"schema":{"type":"struct","fields":[{"type":"struct","fields":[{"type":"string","optional":true,"field":"name"},{"type":"double","optional":true,"field":"scores"}],"optional":true,"name":"ALAN.cdctest.userscoressink.Value","field":"before"},{"type":"struct","fields":[{"type":"string","optional":true,"field":"name"},{"type":"double","optional":true,"field":"scores"}],"optional":true,"name":"ALAN.cdctest.userscoressink.Value","field":"after"},{"type":"struct","fields":[{"type":"string","optional":false,"field":"version"},{"type":"string","optional":false,"field":"connector"},{"type":"string","optional":false,"field":"name"},{"type":"int64","optional":false,"field":"ts_ms"},{"type":"string","optional":true,"name":"io.debezium.data.Enum","version":1,"parameters":{"allowed":"true,last,false"},"default":"false","field":"snapshot"},{"type":"string","optional":false,"field":"db"},{"type":"string","optional":true,"field":"sequence"},{"type":"string","optional":true,"field":"table"},{"type":"int64","optional":false,"field":"server_id"},{"type":"string","optional":true,"field":"gtid"},{"type":"string","optional":false,"field":"file"},{"type":"int64","optional":false,"field":"pos"},{"type":"int32","optional":false,"field":"row"},{"type":"int64","optional":true,"field":"thread"},{"type":"string","optional":true,"field":"query"}],"optional":false,"name":"io.debezium.connector.mysql.Source","field":"source"},{"type":"string","optional":false,"field":"op"},{"type":"int64","optional":true,"field":"ts_ms"},{"type":"struct","fields":[{"type":"string","optional":false,"field":"id"},{"type":"int64","optional":false,"field":"total_order"},{"type":"int64","optional":false,"field":"data_collection_order"}],"optional":true,"field":"transaction"}],"optional":false,"name":"ALAN.cdctest.userscoressink.Envelope"},"payload":{"before":null,"after":{"name":"alan_test","scores":666.0},"source":{"version":"1.7.2.Final","connector":"mysql","name":"ALAN","ts_ms":1705717276000,"snapshot":"false","db":"cdctest","sequence":null,"table":"userscoressink","server_id":1,"gtid":null,"file":"alan_master_logbin.000004","pos":4645,"row":0,"thread":null,"query":null},"op":"c","ts_ms":1705717750512,"transaction":null}}{"schema":{"type":"struct","fields":[{"type":"struct","fields":[{"type":"string","optional":true,"field":"name"},{"type":"double","optional":true,"field":"scores"}],"optional":true,"name":"ALAN.cdctest.userscoressink.Value","field":"before"},{"type":"struct","fields":[{"type":"string","optional":true,"field":"name"},{"type":"double","optional":true,"field":"scores"}],"optional":true,"name":"ALAN.cdctest.userscoressink.Value","field":"after"},{"type":"struct","fields":[{"type":"string","optional":false,"field":"version"},{"type":"string","optional":false,"field":"connector"},{"type":"string","optional":false,"field":"name"},{"type":"int64","optional":false,"field":"ts_ms"},{"type":"string","optional":true,"name":"io.debezium.data.Enum","version":1,"parameters":{"allowed":"true,last,false"},"default":"false","field":"snapshot"},{"type":"string","optional":false,"field":"db"},{"type":"string","optional":true,"field":"sequence"},{"type":"string","optional":true,"field":"table"},{"type":"int64","optional":false,"field":"server_id"},{"type":"string","optional":true,"field":"gtid"},{"type":"string","optional":false,"field":"file"},{"type":"int64","optional":false,"field":"pos"},{"type":"int32","optional":false,"field":"row"},{"type":"int64","optional":true,"field":"thread"},{"type":"string","optional":true,"field":"query"}],"optional":false,"name":"io.debezium.connector.mysql.Source","field":"source"},{"type":"string","optional":false,"field":"op"},{"type":"int64","optional":true,"field":"ts_ms"},{"type":"struct","fields":[{"type":"string","optional":false,"field":"id"},{"type":"int64","optional":false,"field":"total_order"},{"type":"int64","optional":false,"field":"data_collection_order"}],"optional":true,"field":"transaction"}],"optional":false,"name":"ALAN.cdctest.userscoressink.Envelope"},"payload":{"before":{"name":"alan_test","scores":666.0},"after":{"name":"alan_test","scores":888.0},"source":{"version":"1.7.2.Final","connector":"mysql","name":"ALAN","ts_ms":1705717298000,"snapshot":"false","db":"cdctest","sequence":null,"table":"userscoressink","server_id":1,"gtid":null,"file":"alan_master_logbin.000004","pos":4931,"row":0,"thread":null,"query":null},"op":"u","ts_ms":1705717772785,"transaction":null}}{"schema":{"type":"struct","fields":[{"type":"struct","fields":[{"type":"string","optional":true,"field":"name"},{"type":"double","optional":true,"field":"scores"}],"optional":true,"name":"ALAN.cdctest.userscoressink.Value","field":"before"},{"type":"struct","fields":[{"type":"string","optional":true,"field":"name"},{"type":"double","optional":true,"field":"scores"}],"optional":true,"name":"ALAN.cdctest.userscoressink.Value","field":"after"},{"type":"struct","fields":[{"type":"string","optional":false,"field":"version"},{"type":"string","optional":false,"field":"connector"},{"type":"string","optional":false,"field":"name"},{"type":"int64","optional":false,"field":"ts_ms"},{"type":"string","optional":true,"name":"io.debezium.data.Enum","version":1,"parameters":{"allowed":"true,last,false"},"default":"false","field":"snapshot"},{"type":"string","optional":false,"field":"db"},{"type":"string","optional":true,"field":"sequence"},{"type":"string","optional":true,"field":"table"},{"type":"int64","optional":false,"field":"server_id"},{"type":"string","optional":true,"field":"gtid"},{"type":"string","optional":false,"field":"file"},{"type":"int64","optional":false,"field":"pos"},{"type":"int32","optional":false,"field":"row"},{"type":"int64","optional":true,"field":"thread"},{"type":"string","optional":true,"field":"query"}],"optional":false,"name":"io.debezium.connector.mysql.Source","field":"source"},{"type":"string","optional":false,"field":"op"},{"type":"int64","optional":true,"field":"ts_ms"},{"type":"struct","fields":[{"type":"string","optional":false,"field":"id"},{"type":"int64","optional":false,"field":"total_order"},{"type":"int64","optional":false,"field":"data_collection_order"}],"optional":true,"field":"transaction"}],"optional":false,"name":"ALAN.cdctest.userscoressink.Envelope"},"payload":{"before":{"name":"alan_test","scores":888.0},"after":null,"source":{"version":"1.7.2.Final","connector":"mysql","name":"ALAN","ts_ms":1705717322000,"snapshot":"false","db":"cdctest","sequence":null,"table":"userscoressink","server_id":1,"gtid":null,"file":"alan_master_logbin.000004","pos":5234,"row":0,"thread":null,"query":null},"op":"d","ts_ms":1705717796886,"transaction":null}}

以上，本文详细的介绍了debezium的部署、验证以及通过一个示例介绍其使用。

本专题文章分为如下几篇：

标签： flink 大数据 kafka

本文转载自: https://blog.csdn.net/chenwewi520feng/article/details/135773037
版权归原作者 一瓢一瓢的饮 alanchanchn 所有，如有侵权，请联系我们删除。