通过Apache-kafka将事件从MySQL删除到PostgreSQL

2023年2月5日 216次阅读

我正在尝试使用Apache Kafka将事件从
MySQL传输到PostgreSQL.尽管插入和更新工作正常,但我无法弄清楚如何从MySQL中删除记录并将此事件传输到PostgreSQL.

假设以下拓扑：

               +-------------+
               |             |
               |    MySQL    |
               |             |
               +------+------+
                      |
                      |
                      |
      +---------------v------------------+
      |                                  |
      |           Kafka Connect          |
      |  (Debezium, JDBC connectors)     |
      |                                  |
      +---------------+------------------+
                      |
                      |
                      |
                      |
              +-------v--------+
              |                |
              |   PostgreSQL   |
              |                |
              +----------------+

我正在使用以下docker图像;

> Apache-Zookeper
> Apache-Kafka
> Debezium/JDBC connectors

然后

# Start the application
export DEBEZIUM_VERSION=0.6
docker-compose up

# Start PostgreSQL connector
curl -i -X POST -H "Accept:application/json" -H  "Content-Type:application/json" http://localhost:8083/connectors/ -d @jdbc-sink.json

# Start MySQL connector
curl -i -X POST -H "Accept:application/json" -H  "Content-Type:application/json" http://localhost:8083/connectors/ -d @source.json

这是MySQL数据库的内容;

docker-compose -f docker-compose-jdbc.yaml exec mysql bash -c 'mysql -u $MYSQL_USER  -p$MYSQL_PASSWORD inventory -e "select * from customers"'
+------+------------+-----------+-----------------------+
| id   | first_name | last_name | email                 |
+------+------------+-----------+-----------------------+
| 1001 | Sally      | Thomas    | sally.thomas@acme.com |
| 1002 | George     | Bailey    | gbailey@foobar.com    |
| 1003 | Edward     | Walker    | ed@walker.com         |
| 1004 | Anne       | Kretchmar | annek@noanswer.org    |
+------+------------+-----------+-----------------------+

我们可以验证PostgresSQL的内容是否相同;

docker-compose -f docker-compose-jdbc.yaml exec postgres bash -c 'psql -U $POSTGRES_USER $POSTGRES_DB -c "select * from customers"'
 last_name |  id  | first_name |         email         
-----------+------+------------+-----------------------
 Thomas    | 1001 | Sally      | sally.thomas@acme.com
 Bailey    | 1002 | George     | gbailey@foobar.com
 Walker    | 1003 | Edward     | ed@walker.com
 Kretchmar | 1004 | Anne       | annek@noanswer.org
(4 rows)

假设我想从MySQL数据库中删除id = 1004的记录;

docker-compose -f docker-compose-jdbc.yaml exec mysql bash -c 'mysql -u $MYSQL_USER  -p$MYSQL_PASSWORD inventory'
mysql> delete from customers where id = 1004;


docker-compose -f docker-compose-jdbc.yaml exec mysql bash -c 'mysql -u $MYSQL_USER  -p$MYSQL_PASSWORD inventory -e "select * from customers"'
+------+------------+-----------+-----------------------+
| id   | first_name | last_name | email                 |
+------+------------+-----------+-----------------------+
| 1001 | Sally      | Thomas    | sally.thomas@acme.com |
| 1002 | George     | Bailey    | gbailey@foobar.com    |
| 1003 | Edward     | Walker    | ed@walker.com         |
+------+------------+-----------+-----------------------+

虽然该记录已从MySQL中删除,但该条目仍会出现在PostgresSQL中

docker-compose -f docker-compose-jdbc.yaml exec postgres bash -c 'psql -U $POSTGRES_USER $POSTGRES_DB -c "select * from customers"'

 last_name |  id  | first_name |         email         
-----------+------+------------+-----------------------
 Thomas    | 1001 | Sally      | sally.thomas@acme.com
 Bailey    | 1002 | George     | gbailey@foobar.com
 Walker    | 1003 | Edward     | ed@walker.com
 Kretchmar | 1004 | Anne       | annek@noanswer.org
(4 rows)

我知道支持软删除,是否可以从PostgresSQL中完全删除该特定条目(通过Apache-Kafka从MySQL流式传输del事件)？

编辑：

这是source.json文件的内容

{
    "name": "inventory-connector",
    "config": {
        "connector.class": "io.debezium.connector.mysql.MySqlConnector",
        "tasks.max": "1",
        "database.hostname": "mysql",
        "database.port": "3306",
        "database.user": "debezium",
        "database.password": "dbz",
        "database.server.id": "184054",
        "database.server.name": "dbserver1",
        "database.whitelist": "inventory",
        "database.history.kafka.bootstrap.servers": "kafka:9092",
        "database.history.kafka.topic": "schema-changes.inventory",
        "transforms": "route",
        "transforms.route.type": "org.apache.kafka.connect.transforms.RegexRouter",
        "transforms.route.regex": "([^.]+)\\.([^.]+)\\.([^.]+)",
        "transforms.route.replacement": "$3"
    }
}

这是jdbc-sink.json文件的内容

{
    "name": "jdbc-sink",
    "config": {
        "connector.class": "io.confluent.connect.jdbc.JdbcSinkConnector",
        "tasks.max": "1",
        "topics": "customers",
        "connection.url": "jdbc:postgresql://postgres:5432/inventory?user=postgresuser&password=postgrespw",
        "transforms": "unwrap",
        "transforms.unwrap.type": "io.debezium.transforms.UnwrapFromEnvelope",
        "auto.create": "true",
        "insert.mode": "upsert",
        "pk.fields": "id",
        "pk.mode": "record_value"
    }
}

我也尝试设置“pk.mode”：“record_key”和“delete.enabled”：“true”(bug fix suggestion),但这种修改似乎不起作用.

最佳答案 Confluent JDBC接收器当前不支持删除.有一个待处理的拉取请求(您已经链接到它),但尚未合并.

目前,您可以自己构建基于该分支的JDBC接收器连接器,或者创建一个简单的自定义接收器连接器,它只通过在目标数据库上执行相应的DELETE语句来处理逻辑删除事件.

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