【Flink1.14实战】Docker环境 Print SQL 连接器

Print SQL 连接器

Print 连接器允许将每一行写入标准输出流或者标准错误流。

设计目的：

• 简单的流作业测试。
• 对生产调试带来极大便利。

如何创建一张基于 Print 的表

CREATE TABLE print_table (
 f0 INT,
 f1 INT,
 f2 STRING,
 f3 DOUBLE
) WITH (
 'connector' = 'print'
)

或者，也可以通过 LIKE子句基于已有表的结构去创建新表。

CREATE TABLE print_table WITH ('connector' = 'print')
LIKE source_table (EXCLUDING ALL)

实战

基于docker-compose。

1、编辑 docker-compose.yml

version: "3"
services:
  jobmanager:
    image: flink:1.14.4-scala_2.11
    ports:
      - "8081:8081"
    command: jobmanager
    environment:
      - |
        FLINK_PROPERTIES=
        jobmanager.rpc.address: jobmanager        

  taskmanager:
    image: flink:1.14.4-scala_2.11
    depends_on:
      - jobmanager
    command: taskmanager
    scale: 1
    environment:
      - |
        FLINK_PROPERTIES=
        jobmanager.rpc.address: jobmanager
        taskmanager.numberOfTaskSlots: 4   

2、创建执行程序

package quick.table;



import org.apache.flink.table.api.EnvironmentSettings;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.TableEnvironment;


public class PrintSqlExample {
    public static void main(String[] args) throws Exception {
        String sql="CREATE TABLE source_table (\n" +
                "    user_id INT,\n" +
                "    cost DOUBLE,\n" +
                "    ts AS localtimestamp,\n" +
                "    WATERMARK FOR ts AS ts\n" +
                ") WITH (\n" +
                "    'connector' = 'datagen',\n" +
                "    'rows-per-second'='5',\n" +
                "\n" +
                "    'fields.user_id.kind'='random',\n" +
                "    'fields.user_id.min'='1',\n" +
                "    'fields.user_id.max'='10',\n" +
                "\n" +
                "    'fields.cost.kind'='random',\n" +
                "    'fields.cost.min'='1',\n" +
                "    'fields.cost.max'='100'\n" +
                ")\n";
        String sinkSql="CREATE TABLE print_table (\n" +
                " user_id INT,\n" +
                " cost DOUBLE\n" +
                ") WITH (\n" +
                " 'connector' = 'print'\n" +
                ")";
        EnvironmentSettings settings = EnvironmentSettings.newInstance().build();
        TableEnvironment tEnv = TableEnvironment.create(settings);

        tEnv.executeSql(sql);

        tEnv.executeSql(sinkSql);
        // 执行查询
        Table table = tEnv.sqlQuery("select user_id,cost from source_table");

        table.executeInsert("print_table");
    }
}

3、启动服务

$ docker-compose up -d

4、打印结果

然后，将打包应用程序提交，Flink 的Web UI来提交作业监控集群的状态和正在运行的作业。

$ docker-compose logs -f taskmanager