1、hudi介绍：

Hudi 是一个开源的大数据存储和处理框架，通过提供数据表、写入、读取、更新和删除等功能，实现了高效的增量数据处理和数据管理。它广泛应用于大数据领域，为数据湖环境下的数据操作提供了强大的支持。不仅可以存储数据，也可以将元数据存在在其中。

优点：不在只依赖于分布式的文件存储系统，对分布式具有解耦合，数据的存储位置可以不用固定，数据并不是只能存储在hdfs中了。

主要的作用：计算引擎可以是Spark、Flink ，存储系统可以是HDFS、OSS、S3，所以可以解除计算引擎和存储系统之间的强耦合。

2、Flink 整合 hudi

# 1、上传jar包到flink lib目录下
hudi-flink1.15-bundle-0.13.1.jar

# 2、重启flink集群
yarn application -list
yarn application -kill application_1699579932721_0004
yarn-session.sh -d -s 4[指定任务的并行度是4，这是hudi官网推荐的]    

批处理：


-- sets up the result mode to tableau to show the results directly in the CLI
set sql-client.execution.result-mode = tableau;

CREATE TABLE t1(
  uuid VARCHAR(20) PRIMARY KEY NOT ENFORCED,
  name VARCHAR(10),
  age INT,
  ts TIMESTAMP(3),
  `partition` VARCHAR(20)
)
PARTITIONED BY (`partition`)
WITH (
  'connector' = 'hudi',
  'path' = 'hdfs://master:9000/data/hudi/t1',
  'table.type' = 'MERGE_ON_READ' -- this creates a MERGE_ON_READ table, by default is COPY_ON_WRITE
);

-- insert data using values
INSERT INTO t1 VALUES
  ('id1','Danny',23,TIMESTAMP '1970-01-01 00:00:01','par1'),
  ('id2','Stephen',33,TIMESTAMP '1970-01-01 00:00:02','par1'),
  ('id3','Julian',53,TIMESTAMP '1970-01-01 00:00:03','par2'),
  ('id4','Fabian',31,TIMESTAMP '1970-01-01 00:00:04','par2'),
  ('id5','Sophia',18,TIMESTAMP '1970-01-01 00:00:05','par3'),
  ('id6','Emma',20,TIMESTAMP '1970-01-01 00:00:06','par3'),
  ('id7','Bob',44,TIMESTAMP '1970-01-01 00:00:07','par4'),
  ('id8','Han',56,TIMESTAMP '1970-01-01 00:00:08','par4');

想要变成流处理，需要在建表的时候指定参数：

-- 查询表
select * from t1;

'read.streaming.enabled' = 'true', 'read.start-commit' = '20210316134557','read.streaming.check-interval' = '4'

-- 流式查询，可以使用hint，修改其中的参数：
select * from t1 /*+OPTIONS('read.streaming.enabled' = 'true', 'read.start-commit' = '20210316134557','read.streaming.check-interval' = '4') */

-- 插入新的数据
INSERT INTO t1 VALUES
('id1','Danny',23,TIMESTAMP '1970-01-01 00:00:01','par1');

--只适用于batch模式：  
UPDATE t1 SET age=19 WHERE uuid in ('id1', 'id2');

3、Flink CDC 整合 hudi

-- 创建Flink CDC 表：

CREATE TABLE students_cdc (
    id BIGINT,
    name STRING,
    age BIGINT,
    gender STRING,
    clazz STRING,
    PRIMARY KEY (id) NOT ENFORCED -- 主键
) WITH (
 'connector' = 'mysql-cdc',
 'hostname' = 'master',
 'port' = '3306',
 'username' = 'root',
 'password' = '123456',
 'database-name' = 'student',
 'table-name' = 'student'
);




-- 创建hudi表
CREATE TABLE students_hudi(
    id BIGINT,
    name STRING,
    age BIGINT,
    gender STRING,
    clazz STRING,
    PRIMARY KEY (id) NOT ENFORCED -- 主键
)
WITH (
  'connector' = 'hudi',
  'path' = 'hdfs://master:9000/data/hudi/students',
  'table.type' = 'MERGE_ON_READ' -- this creates a MERGE_ON_READ table, by default is COPY_ON_WRITE
);

-- 查询cdc表将数据实时写入hudi表中
insert into students_hudi
select * from 
students_cdc;


select * from  students_hudi
/*+OPTIONS('read.streaming.enabled' = 'true', 'read.start-commit' = '20210316134557','read.streaming.check-interval' = '4') */;