系列文章目次
- 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 利用流程
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-即席查询办理方案。
6.1 场景介绍
随着向量化、CBO(Cost Based Optimizer,基于代价的优化器)、单机多核调理等技术的应用,StarRocks的盘算能力逐步提升。许多时候在使用StarRocks举行数仓分层建模时,大部门将数据建模到DWD层(底子整合层)或DWS层(维度宽度)。在实际业务中,运用StarRocks的盘算能力,可以直接查询DWD或DWS层数据,还可以机动地交互式即席查询。
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洗濯导入Kafka的日志大概通过Flink-CDC-StarRocks工具读取MySQL Binlog导入StarRocks。根据需要选用明细、聚合、更新或主键各种模子,只物理落地ODS层(格式整理层)。
(2)向上接纳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,查询时现场盘算指标结果,保证指标上卷和下钻高度同源同等。
6.3 方案特点
该方案主要特点是,盘算逻辑在StarRocks侧(现场查询),实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
机动性强,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。
实用场景
数据泉源于数据库和埋点系统,适合对QPS要求不高,对机动性要求比力高,且盘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 利用流程
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 )
- );
复制代码 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"
- );
复制代码 (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;
复制代码 (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;
复制代码 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举行修改。
- 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'
- );
复制代码 (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举行修改。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'
- );
复制代码 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,然后摆设运行。
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;
复制代码 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");
复制代码 (2)在EMR StarRocks Manager中举行查询
1)查看orders表信息
- select * from flink_cdc.orders;
复制代码
2)查看customers表信息
- select * from flink_cdc.customers;
复制代码
3)查询DWD层数据
- select * from flink_cdc.dwd_order_customer_valid;
复制代码
4)查询DWS层数据
- select * from flink_cdc.dws_agg_by_region;
复制代码
(3)在RDS数据库窗口执行以下命令,从orders表中删除一条记载
- DELETE FROM flink_cdc.orders where order_id = 2;
复制代码 (4)再次在EMR StarRocks Manager中举行查询,查看变化
1)查询DWD层数据
- select * from flink_cdc.dwd_order_customer_valid;
复制代码
2)查询DWS层数据
- select * from flink_cdc.dws_agg_by_region;
复制代码
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