flink table&sql canal使用案例

本文项目源码见github：https://github.com/felixzh2020/felixzh-learning-flink/tree/master/canal

版本信息

产品	版本
Flink	1.11.1
flink-cdc-connectors	1.1.0
Java	1.8.0_231
MySQL	5.7.16

Mavan依赖

• pom.xml 依赖部分
  

  <properties>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      <flink.version>1.11.1</flink.version>
  </properties>
  
  <dependencies>
      <dependency>
          <groupId>org.apache.flink</groupId>
          <artifactId>flink-table-common</artifactId>
          <version>${flink.version}</version>
      </dependency>
      <dependency>
          <groupId>org.apache.flink</groupId>
          <artifactId>flink-java</artifactId>
          <version>${flink.version}</version>
      </dependency>
      <dependency>
          <groupId>org.apache.flink</groupId>
          <artifactId>flink-clients_2.11</artifactId>
          <version>${flink.version}</version>
      </dependency>
      <dependency>
          <groupId>org.apache.flink</groupId>
          <artifactId>flink-streaming-java_2.11</artifactId>
          <version>${flink.version}</version>
      </dependency>
      <dependency>
          <groupId>org.apache.flink</groupId>
          <artifactId>flink-table-api-java-bridge_2.11</artifactId>
          <version>${flink.version}</version>
      </dependency>
      <dependency>
          <groupId>org.apache.flink</groupId>
          <artifactId>flink-table-api-java</artifactId>
          <version>${flink.version}</version>
      </dependency>
      <dependency>
          <groupId>org.apache.flink</groupId>
          <artifactId>flink-table-planner-blink_2.11</artifactId>
          <version>${flink.version}</version>
      </dependency>
      <dependency>
          <groupId>org.apache.flink</groupId>
          <artifactId>flink-table-planner-blink_2.11</artifactId>
          <version>${flink.version}</version>
          <type>test-jar</type>
      </dependency>
      <!-- Flink-CDC -->
      <dependency>
          <groupId>com.alibaba.ververica</groupId>
          <artifactId>flink-connector-mysql-cdc</artifactId>
          <version>1.1.0</version>
      </dependency>
  
  </dependencies>

  主从同步配置、数据准备

  • 关闭MySQL服务
  • 在需要被同步的MySQL节点，添加如下配置（可供参考的文档）

    [mysqld]
    # 前面还有其他配置
    # 添加的部分
    server-id = 12345
    log-bin = mysql-bin
    # 必须为ROW
    binlog_format = ROW
    # 必须为FULL，MySQL-5.7后才有该参数
    binlog_row_image  = FULL
    expire_logs_days  = 10

  • 启动MySQL服务
  • 使用如下命令，可查看binlog相关变量配置

    SHOW VARIABLES LIKE '%binlog%';

  • 创建待测试的库、表、数据

    CREATE DATABASE db_inventory_cdc;
    
    CREATE TABLE tb_products_cdc(
    	id INT PRIMARY KEY AUTO_INCREMENT,
    	name VARCHAR(64),
    	description VARCHAR(128)
    );
    
    INSERT INTO tb_products_cdc
    VALUES 
    	(DEFAULT, 'zhangsan', 'aaa'),
    	(DEFAULT, 'lisi', 'bbb'),
    	(DEFAULT, 'wangwu', 'ccc');

  • 创建用于同步的用户，并给予权限（可供参考的文档）

    -- 设置拥有同步权限的用户
    CREATE USER 'flinkuser' IDENTIFIED BY 'flinkpassword';
    -- 赋予同步相关权限
    GRANT SELECT, RELOAD, SHOW DATABASES, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'flinkuser';

  • 创建用户并赋予权限成功后，使用该用户登录MySQL，可以使用以下命令查看主从同步相关信息

    SHOW MASTER STATUS
    SHOW SLAVE STATUS
    SHOW BINARY LOGS

  使用Flink-CDC

  • sql-cli点击查看
  编码方式，方便提交jar包，示例如下
  import org.apache.flink.streaming.api.environment.StreamExecutionEnvironimport org.apache.flink.table.api.EnvironmentSettings;

  import org.apache.flink.table.api.TableResult;
  import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
  import org.apache.flink.table.planner.factories.TestValuesTableFactory;
  public class FlinkCDCSQLTest {
  
      public static void main(String[] args) throws Exception {
          EnvironmentSettings fsSettings = EnvironmentSettings.newInstance()
                  .useBlinkPlanner()
                  .inStreamingMode()
                  .build();
          StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
          env.setParallelism(1);
          StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env, fsSettings);
          
          // 数据源表
          String sourceDDL =
                  "CREATE TABLE mysql_binlog (\n" +
                  " id INT NOT NULL,\n" +
                  " name STRING,\n" +
                  " description STRING\n" +
                  ") WITH (\n" +
                  " 'connector' = 'mysql-cdc',\n" +
                  " 'hostname' = 'localhost',\n" +
                  " 'port' = '3306',\n" +
                  " 'username' = 'flinkuser',\n" +
                  " 'password' = 'flinkpassword',\n" +
                  " 'database-name' = 'db_inventory_cdc',\n" +
                  " 'table-name' = 'tb_products_cdc'\n" +
                  ")";
          // 输出目标表
          String sinkDDL =
                  "CREATE TABLE tb_sink (\n" +
                  " name STRING,\n" +
                  " countSum BIGINT,\n" +
                  " PRIMARY KEY (name) NOT ENFORCED\n" +
                  ") WITH (\n" +
                  " 'connector' = 'print'\n" +
                  ")";
          // 简单的聚合处理
          String transformSQL =
                  "INSERT INTO tb_sink " +
                  "SELECT name, COUNT(1) " +
                  "FROM mysql_binlog " +
                  "GROUP BY name";
                  
          tableEnv.executeSql(sourceDDL);
          tableEnv.executeSql(sinkDDL);
          TableResult result = tableEnv.executeSql(transformSQL);
          
          // 等待flink-cdc完成快照
          waitForSnapshotStarted("tb_sink");
          result.print();
          
          result.getJobClient().get().cancel().get();
      }
  
      private static void waitForSnapshotStarted(String sinkName) throws InterruptedException {
          while (sinkSize(sinkName) == 0) {
              Thread.sleep(100);
          }
      }
  
      private static int sinkSize(String sinkName) {
          synchronized (TestValuesTableFactory.class) {
              try {
                  return TestValuesTableFactory.getRawResults(sinkName).size();
              } catch (IllegalArgumentException e) {
                  // job is not started yet
                  return 0;
              }
          }
      }
  
  }

  简单的测试

  • 进行简单测试，开始修改MySQL表的数据

    -- SQL测试数据，对照Flink应用
    
    INSERT INTO tb_products_cdc VALUE(DEFAULT, 'lisi', 'ddd');
    
    DELETE FROM tb_products_cdc WHERE id=4;
    
    UPDATE tb_products_cdc SET name='wangwu' WHERE id=2;

  • 执行一条SQL，查看一下Flink的结果变化