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使用Flink CDC实现 Oracle数据库数据同步

2024-11-30数据库40

Flink CDC 是一个基于流的数据集成工具,旨在为用户提供一套功能更加全面的编程接口(API)。 该工具使得用户能够以 YAML 配置文件的形式实现数据库同步,同时也提供了Flink CDC Source Connector API。 Flink CDC 在任务提交过程中进行了优化,并且增加了一些高级特性,如表结构变更自动同步(Schema Evolution)、数据转换(Data Transformation)、整库同步(Full Database Synchronization)以及 精确一次(Exactly-once)语义。
本文通过flink-connector-oracle-cdc来实现Oracle数据库的数据同步。

一、开启归档日志

1)数据库服务器终端,使用sysdba角色连接数据库

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sqlplus / as sysdba
sqlplus /nolog
CONNECT sys/password AS SYSDBA;

2)检查归档日志是否开启

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archive log list;

(“Database log mode: No Archive Mode”,日志归档未开启)
(“Database log mode: Archive Mode”,日志归档已开启)
3)启用归档日志

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alter system set db_recovery_file_dest_size = 10G;
alter system set db_recovery_file_dest = '/opt/oracle/oradata/recovery_area' scope=spfile;
shutdown immediate;
startup mount;
alter database archivelog;
alter database open;

注意:
启用归档日志需要重启数据库。
归档日志会占用大量的磁盘空间,应定期清除过期的日志文件
4)启动完成后重新执行 archive log list; 查看归档打开状态

二、创建flinkcdc专属用户

2.1 对于Oracle 非CDB数据库,执行如下sql

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CREATE USER flinkuser IDENTIFIED BY flinkpw DEFAULT TABLESPACE LOGMINER_TBS QUOTA UNLIMITED ON LOGMINER_TBS;
GRANT CREATE SESSION TO flinkuser;
GRANT SET CONTAINER TO flinkuser;
GRANT SELECT ON V_$DATABASE to flinkuser;
GRANT FLASHBACK ANY TABLE TO flinkuser;
GRANT SELECT ANY TABLE TO flinkuser;
GRANT SELECT_CATALOG_ROLE TO flinkuser;
GRANT EXECUTE_CATALOG_ROLE TO flinkuser;
GRANT SELECT ANY TRANSACTION TO flinkuser;
GRANT LOGMINING TO flinkuser;
GRANT ANALYZE ANY TO flinkuser;
GRANT CREATE TABLE TO flinkuser;
-- need not to execute if set scan.incremental.snapshot.enabled=true(default)
GRANT LOCK ANY TABLE TO flinkuser;
GRANT ALTER ANY TABLE TO flinkuser;
GRANT CREATE SEQUENCE TO flinkuser;
GRANT EXECUTE ON DBMS_LOGMNR TO flinkuser;
GRANT EXECUTE ON DBMS_LOGMNR_D TO flinkuser;
GRANT SELECT ON V_$LOG TO flinkuser;
GRANT SELECT ON V_$LOG_HISTORY TO flinkuser;
GRANT SELECT ON V_$LOGMNR_LOGS TO flinkuser;
GRANT SELECT ON V_$LOGMNR_CONTENTS TO flinkuser;
GRANT SELECT ON V_$LOGMNR_PARAMETERS TO flinkuser;
GRANT SELECT ON V_$LOGFILE TO flinkuser;
GRANT SELECT ON V_$ARCHIVED_LOG TO flinkuser;
GRANT SELECT ON V_$ARCHIVE_DEST_STATUS TO flinkuser;

2.2 对于Oracle CDB数据库,执行如下sql

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CREATE USER flinkuser IDENTIFIED BY flinkpw DEFAULT TABLESPACE logminer_tbs QUOTA UNLIMITED ON logminer_tbs CONTAINER=ALL;
GRANT CREATE SESSION TO flinkuser CONTAINER=ALL;
GRANT SET CONTAINER TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$DATABASE to flinkuser CONTAINER=ALL;
GRANT FLASHBACK ANY TABLE TO flinkuser CONTAINER=ALL;
GRANT SELECT ANY TABLE TO flinkuser CONTAINER=ALL;
GRANT SELECT_CATALOG_ROLE TO flinkuser CONTAINER=ALL;
GRANT EXECUTE_CATALOG_ROLE TO flinkuser CONTAINER=ALL;
GRANT SELECT ANY TRANSACTION TO flinkuser CONTAINER=ALL;
GRANT LOGMINING TO flinkuser CONTAINER=ALL;
GRANT CREATE TABLE TO flinkuser CONTAINER=ALL;
-- need not to execute if set scan.incremental.snapshot.enabled=true(default)
GRANT LOCK ANY TABLE TO flinkuser CONTAINER=ALL;
GRANT CREATE SEQUENCE TO flinkuser CONTAINER=ALL;
GRANT EXECUTE ON DBMS_LOGMNR TO flinkuser CONTAINER=ALL;
GRANT EXECUTE ON DBMS_LOGMNR_D TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$LOG TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$LOG_HISTORY TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$LOGMNR_LOGS TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$LOGMNR_CONTENTS TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$LOGMNR_PARAMETERS TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$LOGFILE TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$ARCHIVED_LOG TO flinkuser CONTAINER=ALL;
GRANT SELECT ON V_$ARCHIVE_DEST_STATUS TO flinkuser CONTAINER=ALL;

三、指定oracle表、库级启用

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-- 指定表启用补充日志记录:
ALTER TABLE databasename.tablename ADD SUPPLEMENTAL LOG DATA (ALL) COLUMNS;
-- 为数据库的所有表启用
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (ALL) COLUMNS;
-- 指定数据库启用补充日志记录
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

四、使用flink-connector-oracle-cdc实现数据库同步

4.1 引入pom依赖

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<dependency>
    <groupId>com.ververica</groupId>
    <artifactId>flink-connector-oracle-cdc</artifactId>
    <version>2.4.0</version>
</dependency>

4.2 Java主代码

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package test.datastream.cdc.oracle;
import com.ververica.cdc.connectors.oracle.OracleSource;
import com.ververica.cdc.debezium.JsonDebeziumDeserializationSchema;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.source.SourceFunction;
import org.apache.flink.streaming.api.windowing.assigners.TumblingProcessingTimeWindows;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.types.Row;
import test.datastream.cdc.oracle.function.CacheDataAllWindowFunction;
import test.datastream.cdc.oracle.function.CdcString2RowMap;
import test.datastream.cdc.oracle.function.DbCdcSinkFunction;
import java.util.Properties;
public class OracleCdcExample {
    public static void main(String[] args) throws Exception {
        Properties properties = new Properties();
        //数字类型数据 转换为字符
        properties.setProperty("decimal.handling.mode", "string");
        SourceFunction<String> sourceFunction = OracleSource.<String>builder()
//                .startupOptions(StartupOptions.latest()) // 从最晚位点启动
                .url("jdbc:oracle:thin:@localhost:1521:orcl")
                .port(1521)
                .database("ORCL") // monitor XE database
                .schemaList("c##flink_user") // monitor inventory schema
                .tableList("c##flink_user.TEST2") // monitor products table
                .username("c##flink_user")
                .password("flinkpw")
                .debeziumProperties(properties)
                .deserializer(new JsonDebeziumDeserializationSchema()) // converts SourceRecord to JSON String
                .build();
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        DataStreamSource<String> source = env.addSource(sourceFunction).setParallelism(1);// use parallelism 1 for sink to keep message ordering
        SingleOutputStreamOperator<Row> mapStream = source.flatMap(new CdcString2RowMap());
        SingleOutputStreamOperator<Row[]> winStream = mapStream.windowAll(TumblingProcessingTimeWindows.of(Time.seconds(5)))
                .process(new CacheDataAllWindowFunction());
        //批量同步
        winStream.addSink(new DbCdcSinkFunction(null));
        env.execute();
    }
}

4.3json转换为row

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package test.datastream.cdc.oracle.function;
import cn.com.victorysoft.common.configuration.VsConfiguration;
import org.apache.flink.api.common.functions.RichFlatMapFunction;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.types.Row;
import org.apache.flink.types.RowKind;
import org.apache.flink.util.Collector;
import test.datastream.cdc.CdcConstants;
import java.sql.Timestamp;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
 * @desc cdc json解析,并转换为Row
 */
public class CdcString2RowMap extends RichFlatMapFunction<String, Row> {
    private Map<String,Integer> columnMap =new HashMap<>();
    @Override
    public void open(Configuration parameters) throws Exception {
        columnMap.put("ID",0);
        columnMap.put("NAME",1);
        columnMap.put("DESCRIPTION",2);
        columnMap.put("AGE",3);
        columnMap.put("CREATE_TIME",4);
        columnMap.put("SCORE",5);
        columnMap.put("C_1",6);
        columnMap.put("B_1",7);
    }
    @Override
    public void flatMap(String s, Collector<Row> collector) throws Exception {
        System.out.println("receive: "+s);
        VsConfiguration conf=VsConfiguration.from(s);
        String op = conf.getString(CdcConstants.K_OP);
        VsConfiguration before = conf.getConfiguration(CdcConstants.K_BEFORE);
        VsConfiguration after = conf.getConfiguration(CdcConstants.K_AFTER);
        Row row =null;
        if(CdcConstants.OP_C.equals(op)){
            //插入,使用after数据
            row = convertToRow(after);
            row.setKind(RowKind.INSERT);
        }else if(CdcConstants.OP_U.equals(op)){
            //更新,使用after数据
            row = convertToRow(after);
            row.setKind(RowKind.UPDATE_AFTER);
        }else if(CdcConstants.OP_D.equals(op)){
            //删除,使用before数据
            row = convertToRow(before);
            row.setKind(RowKind.DELETE);
        }else {
            //r 操作,使用after数据
            row = convertToRow(after);
            row.setKind(RowKind.INSERT);
        }
        collector.collect(row);
    }
    private Row convertToRow(VsConfiguration data){
        Set<String> keys = data.getKeys();
        int size = keys.size();
        Row row=new Row(8);
        int i=0;
        for (String key:keys) {
            Integer index = this.columnMap.get(key);
            Object value=data.get(key);
            if(key.equals("CREATE_TIME")){
                //long日期转timestamp
                value=long2Timestamp((Long)value);
            }
            row.setField(index,value);
        }
        return row;
    }
    private static  java.sql.Timestamp long2Timestamp(Long time){
        Timestamp timestamp = new Timestamp(time/1000);
        System.out.println(timestamp);
        return timestamp;
    }
}