系列文章目录
- 数仓场景:即席查询案例
 6.1 场景介绍
 6.2 方案架构
 6.3 方案特点
 6.4 操作流程
 6.4.1 步骤一:创建MySQL源数据表
 6.4.2 步骤二:创建StarRocks表
 6.4.3 步骤三:执行Flink任务,启动数据流
 6.4.4 步骤四:验证数据
文章目录
- 系列文章目录
- 前言
- 6. 数仓场景:即席查询案例
- 6.1 场景介绍
- 6.2 方案架构
- 6.3 方案特点
 
- 6.4 操作流程
- 6.4.1 步骤一:创建MySQL源数据表
- 6.4.2 步骤二:创建StarRocks表
- 6.4.3 步骤三:执行Flink任务,启动数据流
- 6.4.4 步骤四:验证数据
 
 
前言
本文为Flink-StarRocks详解后续章节:主要详解StarRocks数仓场景:即席查询大案例
6. 数仓场景:即席查询案例
本文通过示例介绍如何基于EMR Serverless StarRocks的视图能力构建数仓场景-即席查询解决方案。
6.1 场景介绍
随着向量化、CBO(Cost Based Optimizer,基于代价的优化器)、单机多核调度等技术的应用,StarRocks的计算能力逐步提升。很多时候在使用StarRocks进行数仓分层建模时,大部分将数据建模到DWD层(基础整合层)或DWS层(维度宽度)。在实际业务中,运用StarRocks的计算能力,可以直接查询DWD或DWS层数据,还可以灵活地交互式即席查询。
6.2 方案架构
使用StarRocks实现数仓场景即席查询的基本架构如下图所示。
 
整体数据流如下:
 (1)Flink清洗导入Kafka的日志或者通过Flink-CDC-StarRocks工具读取MySQL Binlog导入StarRocks。根据需要选用明细、聚合、更新或主键各种模型,只物理落地ODS层(格式整理层)。
 (2)向上采用StarRocks View视图能力,利用StarRocks向量化极速查询和CBO优化器满足多表关联、嵌套子查询等复杂SQL,查询时现场计算指标结果,保证指标上卷和下钻高度同源一致。
6.3 方案特点
该方案主要特点是,计算逻辑在StarRocks侧(现场查询),适用于业务库高频数据更新的场景,实体数据只在ODS或DWD层存储。
  方案优势
  灵活性强,可随时根据业务逻辑调整View。
  指标修正简单,上层都是View逻辑封装,只需要更新底表数据。
  方案缺点
 当View的逻辑较为复杂,数据量较多时,查询性能较低。
  适用场景
  数据来源于数据库和埋点系统,适合对QPS要求不高,对灵活性要求比较高,且计算资源较为充足的场景。
  实时要求非常高,要求写入即可查,更新即反馈。适合有即席查询需求,且资源较为充足,查询复杂度较低的场景。
6.4 操作流程
6.4.1 步骤一:创建MySQL源数据表
(1)登录DMS
 (2)创建库和表
CREATE DATABASE IF NOT EXISTS flink_cdc;
create table flink_cdc.orders (
   order_id INT NOT NULL AUTO_INCREMENT,
   order_revenue FLOAT NOT NULL,
   order_region VARCHAR(40) NOT NULL,
   customer_id INT NOT NULL,
   PRIMARY KEY ( order_id )
);
create table flink_cdc.customers (
   customer_id INT NOT NULL,
   customer_age INT NOT NULL,
   customer_name VARCHAR(40) NOT NULL,
   PRIMARY KEY ( customer_id )
);
6.4.2 步骤二:创建StarRocks表
(1)登录EMR StarRocks Manager
 (2)创建库和表
CREATE DATABASE IF NOT EXISTS `flink_cdc`;
CREATE TABLE IF NOT EXISTS `flink_cdc`.`customers` (
  `customer_id` INT NOT NULL  COMMENT "",
  `customer_age` FLOAT NOT NULL  COMMENT "",
  `customer_name` STRING NOT NULL  COMMENT ""
) ENGINE=olap
PRIMARY KEY(`customer_id`)
COMMENT ""
DISTRIBUTED BY HASH(`customer_id`) BUCKETS 1
PROPERTIES (
  "replication_num" = "1"
);
CREATE TABLE IF NOT EXISTS `flink_cdc`.`orders` (
  `order_id` INT NOT NULL  COMMENT "",
  `order_revenue` FLOAT NOT NULL  COMMENT "",
  `order_region` STRING NOT NULL  COMMENT "",
  `customer_id` INT NOT NULL  COMMENT ""
) ENGINE=olap
PRIMARY KEY(`order_id`)
COMMENT ""
DISTRIBUTED BY HASH(`order_id`) BUCKETS 1
PROPERTIES (
  "replication_num" = "1"
);
(3)基于ODS表创建DWD视图
CREATE VIEW flink_cdc.dwd_order_customer_valid (
  order_id,
  order_revenue,
  order_region,
  customer_id,
  customer_age,
  customer_name
)
AS
SELECT o.order_id, o.order_revenue, o.order_region, c.customer_id, c.customer_age, c.customer_name
FROM flink_cdc.customers c JOIN flink_cdc.orders o
ON c.customer_id=o.customer_id
WHERE c.customer_id != -1;
(4)基于DWD表创建DWS视图
CREATE VIEW flink_cdc.dws_agg_by_region (
  order_region,
  order_cnt,
  order_total_revenue)
AS
SELECT order_region, count(order_region), sum(order_revenue)
FROM flink_cdc.dwd_order_customer_valid
GROUP BY order_region;
6.4.3 步骤三:执行Flink任务,启动数据流
(1)打开阿里云flink控制台
 (2)创建MySQL CDC映射表
 注意:hostname等需要根据自己的实际情况进行修改。
CREATE DATABASE IF NOT EXISTS `vvp`.`flinkcdc`;
CREATE TABLE IF NOT EXISTS `vvp`.`flinkcdc`.`customers_src` (
  `customer_id` INT NOT NULL,
  `customer_age` FLOAT NOT NULL,
  `customer_name` STRING NOT NULL,
  PRIMARY KEY(`customer_id`) NOT ENFORCED
) with (
 'connector' = 'mysql',
 'hostname' = 'rm-cn-x0r3fp1lj000qa.rwlb.rds.aliyuncs.com',
 'port' = '3306',
 'username' = 'xxxxxx',
 'password' = 'xxxxxx',
 'database-name' = 'flink_cdc',
 'table-name' = 'customers'
);
CREATE TABLE IF NOT EXISTS `vvp`.`flinkcdc`.`orders_src` (
  `order_id` INT NOT NULL,
  `order_revenue` FLOAT NOT NULL,
  `order_region` STRING NOT NULL,
  `customer_id` INT NOT NULL,
  PRIMARY KEY(`order_id`) NOT ENFORCED
) with (
  'connector' = 'mysql',
  'hostname' = 'rm-cn-x0r3fp1lj000qa.rwlb.rds.aliyuncs.com',
  'port' = '3306',
  'username' = 'xxxx',
  'password' = 'xxxxxx!',
  'database-name' = 'flink_cdc',
  'table-name' = 'orders'
);
(3)创建StarRocks映射表
 注意:jdbc-url、load-url等需要根据自己的实际情况进行修改。查询位置为EMR控制台-》StarRocks-》点击实例-》实例详情
CREATE TABLE IF NOT EXISTS `vvp`.`flinkcdc`.`customers_sink` (
  `customer_id` INT NOT NULL,
  `customer_age` FLOAT NOT NULL,
  `customer_name` STRING NOT NULL,
  PRIMARY KEY(`customer_id`)
 NOT ENFORCED
) with (
  'connector' = 'starrocks'
  ,'jdbc-url' = 'jdbc:mysql://fe-c-838fd7a4db1550a6-internal.starrocks.aliyuncs.com:9030'
  ,'load-url' = 'fe-c-838fd7a4db1550a6-internal.starrocks.aliyuncs.com:8030'
  ,'database-name' = 'flink_cdc'
  ,'table-name' = 'customers'
  ,'username' = 'xxxxxx'
  ,'password' = 'xxxxxx'
  ,'sink.buffer-flush.interval-ms' = '5000'
  ,'sink.semantic' = 'exactly-once'
);
CREATE TABLE IF NOT EXISTS `vvp`.`flinkcdc`.`orders_sink` (
  `order_id` INT NOT NULL,
  `order_revenue` FLOAT NOT NULL,
  `order_region` STRING NOT NULL,
  `customer_id` INT NOT NULL,
  PRIMARY KEY(`order_id`)
 NOT ENFORCED
) with (
  'connector' = 'starrocks'
  ,'jdbc-url' = 'jdbc:mysql://fe-c-838fd7a4db1550a6-internal.starrocks.aliyuncs.com:9030'
  ,'load-url' = 'fe-c-838fd7a4db1550a6-internal.starrocks.aliyuncs.com:8030'
  ,'database-name' = 'flink_cdc'
  ,'table-name' = 'orders'
  ,'username' = 'xxxxxx''
  ,'password' = 'xxxxxx'
  ,'sink.buffer-flush.interval-ms' = '5000'
  ,'sink.semantic' = 'exactly-once'
);
 参数含义
 
 
(4)将MySQL数据插入到StarRocks
 以下代码写到一个流作业中,然后部署运行。
 需要无状态启动,并且设置checkpoint周期为5秒
 
BEGIN STATEMENT SET;
INSERT INTO `vvp`.`flinkcdc`.`customers_sink` SELECT * FROM `vvp`.`flinkcdc`.`customers_src`;
INSERT INTO `vvp`.`flinkcdc`.`orders_sink` SELECT * FROM `vvp`.`flinkcdc`.`orders_src`;
END;
6.4.4 步骤四:验证数据
(1)在RDS数据库窗口执行以下命令,向表orders和customers中插入数据。
INSERT INTO flink_cdc.orders(order_id,order_revenue,order_region,customer_id) VALUES(1,10,"beijing",1);
INSERT INTO flink_cdc.orders(order_id,order_revenue,order_region,customer_id) VALUES(2,10,"beijing",1);
INSERT INTO flink_cdc.customers(customer_id,customer_age,customer_name) VALUES(1, 22, "emr_test");
(2)在EMR StarRocks Manager中进行查询
 1)查看orders表信息
select * from flink_cdc.orders;

2)查看customers表信息
select * from flink_cdc.customers;

3)查询DWD层数据
select * from flink_cdc.dwd_order_customer_valid;

4)查询DWS层数据
select * from flink_cdc.dws_agg_by_region;

(3)在RDS数据库窗口执行以下命令,从orders表中删除一条记录
DELETE FROM flink_cdc.orders where order_id = 2;
(4)再次在EMR StarRocks Manager中进行查询,查看变化
 1)查询DWD层数据
select * from flink_cdc.dwd_order_customer_valid;

2)查询DWS层数据
select * from flink_cdc.dws_agg_by_region;




















