Flink CDC 实时同步 Oracle

Flink CDC

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Flink CDC 实时同步 MySQL
Flink CDC 实时同步 Oracle

准备工作

Oracle 数据库（version: 11g）

开启归档日志

sqlplus /nolog

SQL> conn /as sysdba;

-- 立即关闭数据库
SQL> shutdown immediate;

-- 以mount模式启动数据库
SQL> startup mount;

-- 启用数据库归档日志模式
SQL> alter database archivelog;

-- 打开数据库，允许用户访问
SQL> alter database open;

-- 查看归档日志是否启用
SQL> archive log list;

备注：启用日志归档需要重启数据库。归档日志将占用大量的磁盘空间，因此需要定期清理过期的日志。

开启增量日志

sqlplus /nolog

SQL> conn /as sysdba;

SQL> ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

以 DBA 权限登录数据库，赋予用户操作权限

sqlplus /nolog

SQL> conn /as sysdba;

-- 创建一个名为"cdc"的用户，密码为"123456"
SQL> CREATE USER cdc IDENTIFIED BY 123456;

-- 允许"cdc"用户创建会话，即允许该用户连接到数据库。
SQL> GRANT CREATE SESSION TO cdc;

-- （不支持Oracle 11g）允许"cdc"用户在多租户数据库（CDB）中设置容器。
-- SQL> GRANT SET CONTAINER TO cdc;

-- 允许"cdc"用户查询V_$DATABASE视图，该视图包含有关数据库实例的信息。
SQL> GRANT SELECT ON V_$DATABASE TO cdc;

-- 允许"cdc"用户执行任何表的闪回操作。
SQL> GRANT FLASHBACK ANY TABLE TO cdc;

-- 允许"cdc"用户查询任何表的数据。
SQL> GRANT SELECT ANY TABLE TO cdc;

-- 允许"cdc"用户拥有SELECT_CATALOG_ROLE角色，该角色允许查询数据字典和元数据。
SQL> GRANT SELECT_CATALOG_ROLE TO cdc;

-- 允许"cdc"用户拥有EXECUTE_CATALOG_ROLE角色，该角色允许执行一些数据字典中的过程和函数。
SQL> GRANT EXECUTE_CATALOG_ROLE TO cdc;

-- 允许"cdc"用户查询任何事务。
SQL> GRANT SELECT ANY TRANSACTION TO cdc;

-- （不支持Oracle 11g）允许"cdc"用户进行数据变更追踪（LogMiner）。
-- SQL> GRANT LOGMINING TO cdc;

-- 允许"cdc"用户创建表。
SQL> GRANT CREATE TABLE TO cdc;

-- 允许"cdc"用户锁定任何表。
SQL> GRANT LOCK ANY TABLE TO cdc;

-- 允许"cdc"用户修改任何表。
SQL> GRANT ALTER ANY TABLE TO cdc;

-- 允许"cdc"用户创建序列。
SQL> GRANT CREATE SEQUENCE TO cdc;

-- 允许"cdc"用户执行DBMS_LOGMNR包中的过程。
SQL> GRANT EXECUTE ON DBMS_LOGMNR TO cdc;

-- 允许"cdc"用户执行DBMS_LOGMNR_D包中的过程。
SQL> GRANT EXECUTE ON DBMS_LOGMNR_D TO cdc;

-- 允许"cdc"用户查询V_$LOG视图，该视图包含有关数据库日志文件的信息。
SQL> GRANT SELECT ON V_$LOG TO cdc;

-- 允许"cdc"用户查询V_$LOG_HISTORY视图，该视图包含有关数据库历史日志文件的信息。
SQL> GRANT SELECT ON V_$LOG_HISTORY TO cdc;

-- 允许"cdc"用户查询V_$LOGMNR_LOGS视图，该视图包含有关LogMiner日志文件的信息。
SQL> GRANT SELECT ON V_$LOGMNR_LOGS TO cdc;

-- 允许"cdc"用户查询V_$LOGMNR_CONTENTS视图，该视图包含LogMiner日志文件的内容。
SQL> GRANT SELECT ON V_$LOGMNR_CONTENTS TO cdc;

-- 允许"cdc"用户查询V_$LOGMNR_PARAMETERS视图，该视图包含有关LogMiner的参数信息。
SQL> GRANT SELECT ON V_$LOGMNR_PARAMETERS TO cdc;

-- 允许"cdc"用户查询V_$LOGFILE视图，该视图包含有关数据库日志文件的信息。
SQL> GRANT SELECT ON V_$LOGFILE TO cdc;

-- 允许"cdc"用户查询V_$ARCHIVED_LOG视图，该视图包含已归档的数据库日志文件的信息。
SQL> GRANT SELECT ON V_$ARCHIVED_LOG TO cdc;

-- 允许"cdc"用户查询V_$ARCHIVE_DEST_STATUS视图，该视图包含有关归档目标状态的信息。
SQL> GRANT SELECT ON V_$ARCHIVE_DEST_STATUS TO cdc;

Flink (version : 1.18.1)，添加以下 jar 包到 flink/lib：
- flink-connector-jdbc-3.2.0-1.18.jar
- flink-sql-connector-oracle-cdc-3.2-SNAPSHOT.jar
- ojdbc8-19.3.0.0.jar
  
  注意，这里添加的 flink-sql-connector-oracle-cdc 的版本是 3.2-SHAPSHOT, 这是我基于源码自主构建的，因为目前最新的 3.1.0 版本在同步 Oracle 时有 bug，截至版本 3.1.0 发布，尚未对此问题进行修复，但是改动已经合并到了 Master 分支，我们只能基于源码自主构建。详见 flink cdc 源码构建过程

准备待同步源端表和目标端表

源端表：CDC_TEST.PLAYER_SOURCE

CREATE TABLE "CDC_TEST"."PLAYER_SOURCE" (
  "ID" NUMBER(5,0) NOT NULL,
  "NAME" VARCHAR2(255 BYTE)
);

准备目标端表

在目标端创建和源端同构的表：CDC_TEST.PLAYER_TARGET

CREATE TABLE "CDC_TEST"."PLAYER_TARGET" (
  "ID" NUMBER(5,0) NOT NULL,
  "NAME" VARCHAR2(255 BYTE)
);

SQL-Client 实现数据同步

使用 Flink 的 sql-client 实现数据同步

启动 Flink

./bin/start-cluster.sh

启动 sql-client

sudo ./bin/sql-client.sh

注意，这里启动 sql-client 时需要加 sudo，不然可能会报错，参见 [启动 sql-client 报错](#启动 sql-client 报错)

数据同步任务创建

创建源端表对应的逻辑表，参照 Oracle 字段类型和 FlinkSQL 字段类型的映射关系

CREATE TABLE player_source(
    `ID` INT NOT NULL,
    `NAME` STRING,
    PRIMARY KEY(ID) NOT ENFORCED
) WITH (
    'connector' = 'oracle-cdc',
    'hostname' = '127.0.0.1',
    'port' = '1521',
    'username' = 'username',
    'password' = 'password',
    'database-name' = 'cdc',
    'schema-name' = 'CDC_TEST',
    'table-name' = 'PLAYER_SOURCE',
    'debezium.log.mining.strategy' = 'online_catalog',
    'debezium.log.mining.continuous.mine' = 'true'
);

为了解决 Oracle 同步延迟的问题，添加了两个配置项：

'debezium.log.mining.strategy'='online_catalog',
'debezium.log.mining.continuous.mine'='true'

创建目标端表对应的逻辑表

CREATE TABLE player_target(
    `ID` INT NOT NULL,
    `NAME` STRING,
    PRIMARY KEY (`ID`) NOT ENFORCED
) WITH (
    'connector' = 'jdbc',
    'url' = 'jdbc:oracle:thin:@//127.0.0.1:1521/cdc',
    'username' = 'username',
    'password' = 'password',
    'table-name' = 'PLAYER_TARGET',
    'sink.parallelism' = '1'
);

建立源端逻辑表和目标端逻辑表的连接

INSERT INTO player_target SELECT ID, NAME FROM player_source;

任务创建成功：
Flink Web 查看提交的任务：
源端表中进行更新、删除操作，查看目标端表是否自动完成同步

TableAPI 实现数据同步

引入 maven 依赖：

<properties>
    <flink.version>1.18.1</flink.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-table-runtime</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <dependency>
    	<groupId>org.apache.flink</groupId>
	  	<artifactId>flink-table-planner-loader</artifactId>
	  	<version>${flink.version}</version>
	</dependency>
	<dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-runtime-web</artifactId>
        <version>${flink.version}</version>
    </dependency>
    <dependency>
		<groupId>org.apache.flink</groupId>
	    <artifactId>flink-connector-base</artifactId>
	    <version>${flink.version}</version>
	</dependency>
    <dependency>
    	<groupId>org.apache.flink</groupId>
	    <artifactId>flink-connector-jdbc</artifactId>
	    <version>3.1.2-1.18</version>
	</dependency>
	<dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-connector-oracle-cdc</artifactId>
        <version>3.2-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>cn.easyproject</groupId>
        <artifactId>orai18n</artifactId>
        <version>12.1.0.2.0</version>
    </dependency>
<dependencies>

程序实现：

package test.legacy.oracle;

import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.StatementSet;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;

public class FlinkSQL {

	public static void main(String[] args) throws Exception {
        Configuration configuration = new Configuration();
        configuration.setInteger("rest.port", 9091);
        StreamExecutionEnvironment env = StreamExecutionEnvironment.createLocalEnvironmentWithWebUI(configuration);        
        StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env);
        
        // 创建源端逻辑表
        String createSourceTableSQL = "CREATE TABLE player_source (" +
        			"`ID` INT NOT NULL, " +
        			"`NAME` STRING, " +
        			"PRIMARY KEY (`ID`) NOT ENFORCED" +
                ") WITH (" +
                	"'connector' = 'oracle-cdc', " +
                	"'hostname' = '127.0.0.1', " +
                	"'port' = '1521', " +
                	"'username' = 'username', " +
                	"'password' = 'password', " +
                	"'database-name' = 'cdc', " +
                	"'schema-name' = 'CDC_TEST', " +
                	"'table-name' = 'PLAYER_SOURCE', " +
                	"'scan.startup.mode' = 'latest-offset', " +
                	"'debezium.log.mining.strategy' = 'online_catalog', " +
                	"'debezium.log.mining.continuous.mine' = 'true'" +
                ");";
        tableEnv.executeSql(createSourceTableSQL);

        // 创建目标端逻辑表
        String createSinkTableSQL = "CREATE TABLE player_target (" +
        			"`ID` INT NOT NULL, " +
        			"`NAME` STRING, " +
        			"PRIMARY KEY (`ID`) NOT ENFORCED" +
                ") WITH (" +
                	"'connector' = 'jdbc', " +
                	"'url' = 'jdbc:oracle:thin:@//127.0.0.1:1521/cdc', " +
                	"'username' = 'username', " +
                	"'password' = 'password', " +
                	"'table-name' = 'PLAYER_TARGET', " +
                	"'sink.parallelism' = '1'" +
                ");";
        tableEnv.executeSql(createSinkTableSQL);

        // 建立源端逻辑表和目标端逻辑表的连接
        String insertSQL = "INSERT INTO player_target SELECT * FROM player_source;";
        
        StatementSet statementSet = tableEnv.createStatementSet();
        statementSet.addInsertSql(insertSQL);
        statementSet.execute();
    }
}

我们在 Configuration 中设置了 rest.port = 9091, 程序启动成功后，可以在浏览器打开 localhost:9091 看到提交运行的任务。

遇到的问题

启动 sql-client 报错

Exception in thread "main" org.apache.flink.table.client.SqlClientException: Could not read from command line.
        at org.apache.flink.table.client.cli.CliClient.getAndExecuteStatements(CliClient.java:221)
        at org.apache.flink.table.client.cli.CliClient.executeInteractive(CliClient.java:179)
        at org.apache.flink.table.client.cli.CliClient.executeInInteractiveMode(CliClient.java:121)
        at org.apache.flink.table.client.cli.CliClient.executeInInteractiveMode(CliClient.java:114)
        at org.apache.flink.table.client.SqlClient.openCli(SqlClient.java:169)
        at org.apache.flink.table.client.SqlClient.start(SqlClient.java:118)
        at org.apache.flink.table.client.SqlClient.startClient(SqlClient.java:228)
        at org.apache.flink.table.client.SqlClient.main(SqlClient.java:179)
Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.apache.flink.table.client.config.SqlClientOptions
        at org.apache.flink.table.client.cli.parser.SqlClientSyntaxHighlighter.highlight(SqlClientSyntaxHighlighter.java:59)
        at org.jline.reader.impl.LineReaderImpl.getHighlightedBuffer(LineReaderImpl.java:3633)
        at org.jline.reader.impl.LineReaderImpl.getDisplayedBufferWithPrompts(LineReaderImpl.java:3615)
        at org.jline.reader.impl.LineReaderImpl.redisplay(LineReaderImpl.java:3554)
        at org.jline.reader.impl.LineReaderImpl.doCleanup(LineReaderImpl.java:2340)
        at org.jline.reader.impl.LineReaderImpl.cleanup(LineReaderImpl.java:2332)
        at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:626)
        at org.apache.flink.table.client.cli.CliClient.getAndExecuteStatements(CliClient.java:194)
        ... 7 more

是权限问题，只要在启动时添加 sudo 就可以解决：

sudo ./bin/sql-client.sh

启动后还遇到报错：

Please specify JAVA_HOME. Either in Flink config ./conf/flink-conf.yaml or as system-wide JAVA_HOME.

需要在 flink-conf.yaml 中添加：

env.java.home: /opt/java-1.8.0

table or view does not exist

Caused by: java.sql.BatchUpdateException: ORA-00942: table or view does not exist
		at oracle.jdbc.driver.OraclePreparedStatement.executeLargeBatch(OraclePreparedStatement.java:9711)
		at oracle.jdbc.driver.T4CPreparedStatement.executeLargeBatch(T4CPreparedStatement.java:1447)
		at oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:9487)
		at oracle.jdbc.driver.OracleStatementWrapper.executeBatch(OracleStatementWrapper.java:237)
		at org.apache.flink.connector.jdbc.statement.FieldNamedPreparedStatementImpl.executeBatch(FieldNamedPreparedStatementImpl.java:65)
		at org.apache.flink.connector.jdbc.internal.executor.TableSimpleStatementExecutor.executeBatch(TableSimpleStatementExecutor.java:64)
		at org.apache.flink.connector.jdbc.internal.executor.TableBufferReducedStatementExecutor.executeBatch(TableBufferReducedStatementExecutor.java:98)
		at org.apache.flink.connector.jdbc.internal.JdbcOutputFormat.attemptFlush(JdbcOutputFormat.java:202)
		at org.apache.flink.connector.jdbc.internal.JdbcOutputFormat.flush(JdbcOutputFormat.java:172)
		... 8 more

这是 Oracle 11g 对表名大小写敏感的问题。

如果 源端 表名存在小写字母，需要新增以下配置：

'debezium.database.tablename.case.insensitive' = 'true'

如果 目标端 表名存在小写字母，需要用双引号修正表名的大小写：

file is not a valid filed name

Caused by: com.ververica.cdc.connectors.shaded.org.apache.kafka.connect.errors.DataException: file is not a valid field name
	at com.ververica.cdc.connectors.shaded.org.apache.kafka.connect.data.Struct.lookupField(Struct.java:254)
	at com.ververica.cdc.connectors.shaded.org.apache.kafka.connect.data.Struct.getCheckType(Struct.java:261)
	at com.ververica.cdc.connectors.shaded.org.apache.kafka.connect.data.Struct.getString(Struct.java:158)
	at com.ververica.cdc.connectors.base.relational.JdbcSourceEventDispatcher$SchemaChangeEventReceiver.schemaChangeRecordValue(JdbcSourceEventDispatcher.java:193)
	at com.ververica.cdc.connectors.base.relational.JdbcSourceEventDispatcher$SchemaChangeEventReceiver.schemaChangeEvent(JdbcSourceEventDispatcher.java:223)
	at io.debezium.connector.oracle.OracleSchemaChangeEventEmitter.emitSchemaChangeEvent(OracleSchemaChangeEventEmitter.java:122)
	at com.ververica.cdc.connectors.base.relational.JdbcSourceEventDispatcher.dispatchSchemaChangeEvent(JdbcSourceEventDispatcher.java:147)
	at com.ververica.cdc.connectors.base.relational.JdbcSourceEventDispatcher.dispatchSchemaChangeEvent(JdbcSourceEventDispatcher.java:62)
	at io.debezium.connector.oracle.logminer.processor.AbstractLogMinerEventProcessor.dispatchSchemaChangeEventAndGetTableForNewCapturedTable(AbstractLogMinerEventProcessor.java:1018)
	at io.debezium.connector.oracle.logminer.processor.AbstractLogMinerEventProcessor.getTableForDataEvent(AbstractLogMinerEventProcessor.java:913)
	at io.debezium.connector.oracle.logminer.processor.AbstractLogMinerEventProcessor.handleDataEvent(AbstractLogMinerEventProcessor.java:835)
	at io.debezium.connector.oracle.logminer.processor.AbstractLogMinerEventProcessor.processRow(AbstractLogMinerEventProcessor.java:321)
	at com.ververica.cdc.connectors.oracle.source.reader.fetch.EventProcessorFactory$CDCMemoryLogMinerEventProcessor.processRow(EventProcessorFactory.java:151)
	at io.debezium.connector.oracle.logminer.processor.AbstractLogMinerEventProcessor.processResults(AbstractLogMinerEventProcessor.java:262)
	at io.debezium.connector.oracle.logminer.processor.AbstractLogMinerEventProcessor.process(AbstractLogMinerEventProcessor.java:198)
	at io.debezium.connector.oracle.logminer.LogMinerStreamingChangeEventSource.execute(LogMinerStreamingChangeEventSource.java:249)
	... 8 more

这个是 flink-cdc 的 bug，参见 Github 关于此问题的讨论和最新进展：

https://github.com/apache/flink-cdc/pull/2315

https://github.com/apache/flink-cdc/issues/1792

截至目前，3.1 发布版本中尚未对此问题进行修复，但是改动已经合并到了 Master 分支，我们只能基于源码自主构建：

flink cdc 源码构建过程

git clone https://github.com/ververica/flink-cdc-connectors.git
cd flink-cdc-connector
mvn clean install -DskipTests

打包完成后，将 flink-sql-connector-oracle-cdc-3.2-SNAPSHOT.jar 放到 flink/lib 目录下，重启 flink 和 sql-client。

Read the redoLog offset error

Caused by: org.apache.flink.util.FlinkRuntimeException: Read the redoLog offset error
	at org.apache.flink.cdc.connectors.oracle.source.OracleDialect.displayCurrentOffset(OracleDialect.java:70)
	at org.apache.flink.cdc.connectors.oracle.source.OracleDialect.displayCurrentOffset(OracleDialect.java:52)
	at org.apache.flink.cdc.connectors.base.source.reader.external.AbstractScanFetchTask.execute(AbstractScanFetchTask.java:60)
	at org.apache.flink.cdc.connectors.base.source.reader.external.IncrementalSourceScanFetcher.lambda$submitTask$1(IncrementalSourceScanFetcher.java:99)
	... 3 more
Caused by: org.apache.flink.util.FlinkRuntimeException: Cannot read the redo log position via 'SELECT CURRENT_SCN FROM V$DATABASE'. Make sure your server is correctly configured
	at org.apache.flink.cdc.connectors.oracle.source.utils.OracleConnectionUtils.currentRedoLogOffset(OracleConnectionUtils.java:82)
	at org.apache.flink.cdc.connectors.oracle.source.OracleDialect.displayCurrentOffset(OracleDialect.java:68)
	... 6 more

可能是用户权限问题，没有查看 V$DATABASE 的权限。需要 DBA 给用户赋权。

Supplemental logging not configured

Caused by: io.debezium.DebeziumException: Supplemental logging not properly configured. Use: ALTER DATABASE ADD SUPPLEMENTAL LOG DATA
	at io.debezium.connector.oracle.logminer.LogMinerStreamingChangeEventSource.checkDatabaseAndTableState(LogMinerStreamingChangeEventSource.java:860)
	at io.debezium.connector.oracle.logminer.LogMinerStreamingChangeEventSource.execute(LogMinerStreamingChangeEventSource.java:173)
	... 7 more

提示增量日志未开启，切换至 SYS 用户，以 DBA 的权限登录数据库，为数据库启用增量日志：

sqlplus /nolog
SQL> conn /as sysdba;
SQL> ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

posted @ 2024-06-20 07:56 watermark's 阅读(1037) 评论(0) 编辑收藏举报

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watermark

少年辛苦终身事，莫向光阴惰寸功。

Flink CDC 实时同步 Oracle

准备工作

SQL-Client 实现数据同步

启动 Flink

启动 sql-client

数据同步任务创建

TableAPI 实现数据同步

遇到的问题

启动 sql-client 报错

table or view does not exist

file is not a valid filed name

Read the redoLog offset error

Supplemental logging not configured

公告

watermark

少年辛苦终身事， 莫向光阴惰寸功。

Flink CDC 实时同步 Oracle

准备工作

SQL-Client 实现数据同步

启动 Flink

启动 sql-client

数据同步任务创建

TableAPI 实现数据同步

遇到的问题

启动 sql-client 报错

table or view does not exist

file is not a valid filed name

Read the redoLog offset error

Supplemental logging not configured

公告

少年辛苦终身事，莫向光阴惰寸功。