Flink CDC 2.0原理详解和生产实践
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Flink CDC 概念
CDC 的全称是 Change Data Capture ，在广义的概念上，只要能捕获数据变更的技术，我们都可以称为 CDC 。通常我们说的 CDC 技术主要面向 数据库的变更，是一种用于捕获数据库中数据变更的技术。
应用场景
数据同步，用于备份，容灾
数据分发，一个数据源分发给多个下游
数据采集(E)，面向数据仓库/数据湖的 ETL 数据集成
CDC 技术
目前业界主流的实现机制的可以分为两种：
基于查询的 CDC
a.离线调度查询作业，批处理。
b.无法保障数据一致性。
c.不保障实时性。基于日志的 CDC
a.实时消费日志，流处理。
b.保障数据一致性。
c.提供实时数据。常见的开源 CDC 方案
Flink CDC 2.0 设计详解
Source 官网
https://github.com/ververica/flink-cdc-connectors支持的连接
实战应用
pom 文件
Flink-learning
com.wudl.flink
1.0-SNAPSHOT
4.0.0
Flink-cdc2.0
1.13.0
1.8
1.8
org.projectlombok
lombok
1.18.2
provided
org.apache.flink
flink-java
${flink-version}
org.apache.flink
flink-streaming-java_2.12
${flink-version}
org.apache.flink
flink-clients_2.12
${flink-version}
org.apache.hadoop
hadoop-client
3.1.3
mysql
mysql-connector-java
5.1.49
org.apache.flink
flink-table-planner-blink_2.12
${flink-version}
com.ververica
flink-connector-mysql-cdc
2.0.2
com.alibaba
fastjson
1.2.75
org.apache.flink
flink-connector-jdbc_2.12
1.13.3
org.apache.maven.plugins
maven-assembly-plugin
3.0.0
jar-with-dependencies
make-assembly
package
single
代码
package com.wud.cdc2;
import com.ververica.cdc.connectors.mysql.MySqlSource;
import com.ververica.cdc.connectors.mysql.table.StartupOptions;
import com.ververica.cdc.debezium.DebeziumDeserializationSchema;
import com.ververica.cdc.debezium.DebeziumSourceFunction;
import com.ververica.cdc.debezium.StringDebeziumDeserializationSchema;
import org.apache.flink.runtime.state.filesystem.FsStateBackend;
import org.apache.flink.streaming.api.CheckpointingMode;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.CheckpointConfig;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.environment.StreamPipelineOptions;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
import org.apache.flink.types.Row;
import static org.apache.flink.table.api.Expressions.$;
public class FlinkCDC {
public static void main(String[] args) throws Exception {
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.setParallelism(1);
StreamTableEnvironment tabEnv = StreamTableEnvironment.create(env);
env.enableCheckpointing(5000L);
env.getCheckpointConfig().setCheckpointingMode(CheckpointingMode.EXACTLY_ONCE);
// 设置任务关闭时候保留最后一次checkpoint 的数据
env.getCheckpointConfig().enableExternalizedCheckpoints(CheckpointConfig.ExternalizedCheckpointCleanup.RETAIN_ON_CANCELLATION);
// 指定ck 的自动重启策略
env.setStateBackend(new FsStateBackend("hdfs://192.168.1.161:8020/cdc2.0-test/ck"));
// 设置hdfs 的访问用户名
System.setProperty("HADOOP_USER_NAME","hdfs");
DebeziumSourceFunction mySqlSource = MySqlSource.builder()
.hostname("192.168.1.180")
.port(3306)
.username("root")
.password("123456")
.databaseList("test")
.tableList("test.Flink_iceberg")
.deserializer(new StringDebeziumDeserializationSchema())
.startupOptions(StartupOptions.initial())
.build();
DataStreamSource dataStreamSource = env.addSource(mySqlSource);
dataStreamSource.print();
env.execute();
}
} 执行结果
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10011,name=flink-mysql,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585007,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585013}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10012,name=flink-mysqA,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585015,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585016}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10012,name=flink-mysqA,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585017,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585017}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10011,name=flink-mysql,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585017,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585017}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10011,name=flink-mysql,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585017,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585017}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10012,name=flink-mysqA,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585017,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585017}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10013,name=flink-mysqA3,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585017,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585017}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10014,name=flink-mysqA4,age=19,dt=2021-09-28},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585017,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585017}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10011,name=flink-mysql,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585017,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585017}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10012,name=flink-mysqA,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585017,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585018}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10012,name=flink-mysqA,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585018,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585018}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10011,name=flink-mysql,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585018,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585018}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10011,name=flink-mysql,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585018,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585018}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10012,name=flink-mysqA,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585018,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585018}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10013,name=flink-mysqA3,age=19,dt=2021-09-24},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585018,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585018}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765, snapshot=true}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10014,name=flink-mysqA4,age=19,dt=2021-09-28},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585018,snapshot=true,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585018}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1633178585, file=mysql-bin.000036, pos=765}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=10050,name=flink-cdc-add,age=21,dt=2021-10-2},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1633178585018,snapshot=last,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000036,pos=765,row=0},op=r,ts_ms=1633178585018}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}集群提交
执行命令
[root@basenode flink-1.13.2]# bin/flink run -c com.wud.cdc2.FlinkCDC /opt/datas/Flink-cdc2.0-1.0-SNAPSHOT-jar-with-dependencies.jar
Job has been submitted with JobID 137b680a6bb934e43568f14f6583b62c手动执行savepoint
给当前程序创建保存点-savepoint
[root@basenode flink-1.13.2]# bin/flink savepoint e8e918c2517a777e817c630cf1d6b932 hdfs://192.168.1.161:8020/cdc-test/savepoint
Triggering savepoint for job e8e918c2517a777e817c630cf1d6b932.
Waiting for response...
Savepoint completed. Path: hdfs://192.168.1.161:8020/cdc-test/savepoint/savepoint-e8e918-9ef094f349be
You can resume your program from this savepoint with the run command.
[root@basenode flink-1.13.2]#界面停止 flink 程序
然后再mysql中添加数据
启动flink 程序
[root@basenode flink-1.13.2]# bin/flink run -s hdfs://192.168.1.161:8020/cdc-test/savepoint/savepoint-e8e918-9ef094f349be -c com.wud.cdc2.FlinkCDC /opt/datas/Flink-cdc2.0-1.0-SNAPSHOT-jar-with-dependencies.jar
Job has been submitted with JobID 474a0da99820aa6025203f9806b9fcad查看日志：
接下来 flink cdc 2.0 的自定义序列号函数
从上面可以看出flink cdc 的原始结构
SourceRecord{sourcePartition={server=mysql_binlog_source},
sourceOffset={file=mysql-bin.000063, pos=154}}
ConnectRecord{topic='mysql_binlog_source.wudl-gmall.user_info', kafkaPartition=null, key=Struct{id=4000}, keySchema=Schema{mysql_binlog_source.wudl_gmall.user_info.Key:STRUCT}, value=Struct{after=Struct{id=4000,login_name=i0v0k9,nick_name=xxx,name=xxx,phone_num=137xxxxx,[email protected],user_level=1,birthday=1969-12-04,gender=F,create_time=2020-12-04 23:28:45},source=Struct{version=1.4.1.Final,connector=mysql,name=mysql_binlog_source,ts_ms=0,snapshot=last,db=wudl-gmall,table=user_info,server_id=0,file=mysql-bin.000063,pos=154,row=0},op=c,ts_ms=1636255826014}, valueSchema=Schema{mysql_binlog_source.wudl_gmall.user_info.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}我们可以自定义序列化：
package com.wud.cdc2;
import com.alibaba.fastjson.JSONObject;
import com.ververica.cdc.debezium.DebeziumDeserializationSchema;
import io.debezium.data.Envelope;
import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.util.Collector;
import org.apache.kafka.connect.data.Field;
import org.apache.kafka.connect.data.Schema;
import org.apache.kafka.connect.data.Struct;
import org.apache.kafka.connect.source.SourceRecord;
import java.util.List;
public class CustomerDeserialization implements DebeziumDeserializationSchema {
/**
*
* SourceRecord{sourcePartition={server=mysql_binlog_source}, sourceOffset={ts_sec=1636269821, file=mysql-bin.000063, pos=6442}} ConnectRecord{topic='mysql_binlog_source.test.Flink_iceberg', kafkaPartition=null, key=null, keySchema=null, value=Struct{after=Struct{id=102,name=flinksql,age=25,dt=2021-11-08},source=Struct{version=1.5.2.Final,connector=mysql,name=mysql_binlog_source,ts_ms=1636269821531,snapshot=last,db=test,table=Flink_iceberg,server_id=0,file=mysql-bin.000063,pos=6442,row=0},op=r,ts_ms=1636269821531}, valueSchema=Schema{mysql_binlog_source.test.Flink_iceberg.Envelope:STRUCT}, timestamp=null, headers=ConnectHeaders(headers=)}
*
*
*
*
*
* @param sourceRecord 返回一行数据
* @param collector 数据输出
* @throws Exception
*/
@Override
public void deserialize(SourceRecord sourceRecord, Collector collector) throws Exception {
JSONObject result = new JSONObject();
String topic = sourceRecord.topic();
String[] fields = topic.split("\\.");
result.put("db",fields[1]) ;
result.put("tableName",fields[2]);
// 获取before 数据
Struct value = (Struct) sourceRecord.value();
Struct before = value.getStruct("before");
JSONObject beforeJson = new JSONObject();
if (before !=null)
{
//获取列信息
Schema schema = before.schema();
List fieldList = schema.fields();
for (Field field:fieldList)
{
beforeJson.put(field.name(),before.get(field));
}
}
result.put("before",beforeJson);
// 获取after 数据
Struct after = value.getStruct("after");
JSONObject afterJson = new JSONObject();
if (after !=null)
{
Schema schema = after.schema();
List afterFields = schema.fields();
for (Field field:afterFields)
{
afterJson.put(field.name(),after.get(field));
}
}
result.put("after", afterJson);
//获取操作类型
Envelope.Operation operation = Envelope.operationFor(sourceRecord);
result.put("op", operation);
//输出数据
collector.collect(result.toJSONString());
}
@Override
public TypeInformation getProducedType() {
return BasicTypeInfo.STRING_TYPE_INFO;
}
} 调用flink cdc 的自定义函数
package com.wud.cdc2;
import com.ververica.cdc.connectors.mysql.MySqlSource;
import com.ververica.cdc.connectors.mysql.table.StartupOptions;
import com.ververica.cdc.debezium.DebeziumDeserializationSchema;
import com.ververica.cdc.debezium.DebeziumSourceFunction;
import com.ververica.cdc.debezium.StringDebeziumDeserializationSchema;
import org.apache.flink.runtime.state.filesystem.FsStateBackend;
import org.apache.flink.streaming.api.CheckpointingMode;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.CheckpointConfig;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.environment.StreamPipelineOptions;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
import org.apache.flink.types.Row;
public class FlinkCDC {
public static void main(String[] args) throws Exception {
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.setParallelism(1);
// env.enableCheckpointing(5000L);
// env.getCheckpointConfig().setCheckpointingMode(CheckpointingMode.EXACTLY_ONCE);
// // 设置任务关闭时候保留最后一次checkpoint 的数据
// env.getCheckpointConfig().enableExternalizedCheckpoints(CheckpointConfig.ExternalizedCheckpointCleanup.RETAIN_ON_CANCELLATION);
// // 指定ck 的自动重启策略
// env.setStateBackend(new FsStateBackend("hdfs://192.168.1.161:8020/cdc2.0-test/ck"));
// // 设置hdfs 的访问用户名
// System.setProperty("HADOOP_USER_NAME","hdfs");
DebeziumSourceFunction mySqlSource = MySqlSource.builder()
.hostname("192.168.1.180")
.port(3306)
.username("root")
.password("123456")
.databaseList("test")
.tableList("test.Flink_iceberg")
// .deserializer(new StringDebeziumDeserializationSchema())
.deserializer(new CustomerDeserialization())
.startupOptions(StartupOptions.initial())
.build();
DataStreamSource dataStreamSource = env.addSource(mySqlSource);
dataStreamSource.print();
env.execute();
}
} 新增一条数据可以看出 控制台输出结果：
{"op":"UPDATE","before":{"dt":"2021-11-07","name":"spark","id":104,"age":22},"after":{"dt":"2021-11-07","name":"spark02","id":104,"age":22},"db":"test","tableName":"Flink_iceberg"}Flink CDC 2.0 SQL 可以做一个 ETL
需要注意的是必须要有主键 否则更新数据是新增一列，加主键后，更新数据不会新增。
数据库表结构:
CREATE TABLE `Flink_iceberg` (
`id` bigint(64) DEFAULT NULL,
`name` varchar(64) DEFAULT NULL,
`age` int(20) DEFAULT NULL,
`dt` varchar(64) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1实现代码:
package com.wud.cdc2;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
public class FlinkCdc20MysqlToMysql {
public static void main(String[] args) throws Exception {
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.setParallelism(1);
StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env);
String sourceSql = "CREATE TABLE IF NOT EXISTS mySqlSource (" +
"id BIGINT primary key, " +
"name string ," +
"age int," +
"dt string" +
") with ( " +
" 'connector' = 'mysql-cdc', " +
" 'scan.startup.mode' = 'latest-offset', " +
" 'hostname' = '192.168.1.180', " +
" 'port' = '3306', " +
" 'username' = 'root', " +
" 'password' = '123456', " +
" 'database-name' = 'test', " +
" 'table-name' = 'Flink_iceberg' " +
")";
String sinkSql = " CREATE TABLE IF NOT EXISTS mySqlSink (" +
"id BIGINT primary key , " +
"name string ," +
"age int," +
"dt string" +
") with (" +
" 'connector' = 'jdbc'," +
" 'url' = 'jdbc:mysql://192.168.1.180:3306/test'," +
"'table-name' = 'Flink_iceberg-cdc'," +
" 'username' = 'root'," +
" 'password' = '123456' " +
" )";
tableEnv.executeSql(sourceSql);
tableEnv.executeSql(sinkSql);
tableEnv.executeSql("insert into mySqlSink select * from mySqlSource ");
// env.execute("FlinkCdc20MysqlToMysql");
}
}新增一条数据和更新数据显示
{"op":"READ","before":{},"after":{"dt":"2021-09-24","name":"flink-mysqA","id":10012,"age":19},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-09-24","name":"flink-mysqA","id":10012,"age":19},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-09-24","name":"flink-mysql","id":10011,"age":19},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-09-24","name":"flink-mysql","id":10011,"age":19},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-09-24","name":"flink-mysqA","id":10012,"age":19},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-09-24","name":"flink-mysqA3","id":10013,"age":19},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-09-28","name":"flink-mysqA4","id":10014,"age":19},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-09-24","name":"flink-mysql","id":10011,"age":19},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-11-07","name":"flink","id":101,"age":20},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-11-08","name":"flinksql","id":102,"age":25},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-11-09","name":"flink-table","id":103,"age":21},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-11-07","name":"spark","id":104,"age":22},"db":"test","tableName":"Flink_iceberg"}
{"op":"READ","before":{},"after":{"dt":"2021-11-07","name":"hbase","id":105,"age":25},"db":"test","tableName":"Flink_iceberg"}
{"op":"UPDATE","before":{"dt":"2021-11-07","name":"spark","id":104,"age":22},"after":{"dt":"2021-11-07","name":"spark02","id":104,"age":22},"db":"test","tableName":"Flink_iceberg"}
{"op":"CREATE","before":{},"after":{"dt":"2021-11-07","name":"flinkcdc","id":106,"age":22},"db":"test","tableName":"Flink_iceberg"}如果这个文章对你有帮助，不要忘记 「在看」 「点赞」 「收藏」 三连啊喂！
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