SpringCloud Alibaba Seata处理分布式事务

技术2023-07-19 81

一、分布式事务问题

1.1 分布式前

单机单库没这个问题

从1：1 -> 1:N -> N: N

1.2 分布式之后

一句话，一次业务操作需要跨多个数据源或需要跨多个系统进行远程调用，就会产生分布式事务问题。

二、Seata简介

2.1 是什么

Seata是一款开源的分布式事务解决方案，致力于在微服务架构下提供高性能和简单易用的分布式事务服务。

2.1.1 官网地址

http://seata.io/zh-cn/

2.2 能干嘛

2.2.1 一个典型的分布式事务过程

分布式事务处理过程的-ID+三组件模型

Transaction ID XID 全局唯一的事务ID

3组件概念

Transaction Coordinator(TC)：事务协调器，维护全局事务的运行状态，负责协调并驱动全局事务的提交或回滚。Transaction Manager(TM): 控制全局事务的边界，负责开启一个全局事务，并最终发起全局提交或全局回滚的决议。Resource Manager(RM): 控制分支事务，负责分支注册，状态汇报，并接收事务协调器的指令，驱动分支(本地)事务的提交和回滚。

2.2.2 处理过程

2.3 去哪下

发布说明:https://github.com/seata/seata/releases

2.4 怎么玩

本地@Transactional

全局@GlobalTransactinal

2.4.1 Seata的分布式交易解决方案

三、Seata-Server安装

3.1 官网地址

http://seata.io/zh-cn/

3.2 下载版本

seata-server-0.9.0.zip

3.3 seata-server-0.9.0.zip解压到指定目录并修改conf目录下的file.conf配置文件

先备份原始file.conf文件

主要修改：自定义事务组名称+事务日志存储模式为db+数据库连接信息

file.conf

service模块:

vgroup_mapping.my_test_tx_group = "fsp_tx_group"

store模块:

mode = "db" url = "jdbc:mysql://localhost:3306/seata" user = "root" password = "root"

3.4 mysql5.7数据库新建库seata

3.5 在seata库里建表

建表db_store.sql在\seata-server-0.9.0\seata\conf目录里面 db_store.sql

-- the table to store GlobalSession data drop table if exists `global_table`; create table `global_table` ( `xid` varchar(128) not null, `transaction_id` bigint, `status` tinyint not null, `application_id` varchar(32), `transaction_service_group` varchar(32), `transaction_name` varchar(128), `timeout` int, `begin_time` bigint, `application_data` varchar(2000), `gmt_create` datetime, `gmt_modified` datetime, primary key (`xid`), key `idx_gmt_modified_status` (`gmt_modified`, `status`), key `idx_transaction_id` (`transaction_id`) ); -- the table to store BranchSession data drop table if exists `branch_table`; create table `branch_table` ( `branch_id` bigint not null, `xid` varchar(128) not null, `transaction_id` bigint , `resource_group_id` varchar(32), `resource_id` varchar(256) , `lock_key` varchar(128) , `branch_type` varchar(8) , `status` tinyint, `client_id` varchar(64), `application_data` varchar(2000), `gmt_create` datetime, `gmt_modified` datetime, primary key (`branch_id`), key `idx_xid` (`xid`) ); -- the table to store lock data drop table if exists `lock_table`; create table `lock_table` ( `row_key` varchar(128) not null, `xid` varchar(96), `transaction_id` long , `branch_id` long, `resource_id` varchar(256) , `table_name` varchar(32) , `pk` varchar(36) , `gmt_create` datetime , `gmt_modified` datetime, primary key(`row_key`) );

3.6 修改seata-server-0.9.0\seata\conf目录下的registry.conf配置文件

目的是：指明注册中心为nacos，及修改nacos连接信息

3.7 先启动Nacos端口号8848

http://localhost:8848/nacos

3.8 再启动seata-server

安装成功

四、订单/库存/账户业务数据库准备

以下演示都需要先启动Nacos后启动Seata，保证两个都OK

Seata没启动报错no available server to connect

4.1 分布式事务业务说明

4.1.1 业务说明

下订单-->扣库存-->减账户（余额）

4.2 创建业务数据库

seata_order：存储订单的数据库seata_storage：存储库存的数据库seata_account：存储账户信息的数据库

4.2.1 建库SQL

CREATE DATABASE seata_order； CREATE DATABASE seata_storage； CREATE DATABASE seata_account；

4.3 安装上述3库分别建对应业务表

4.3.1 seata_order库下建t_order表

CREATE TABLE t_order( id BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY, user_id BIGINT(11) DEFAULT NULL COMMENT '用户id', product_id BIGINT(11) DEFAULT NULL COMMENT '产品id', count INT(11) DEFAULT NULL COMMENT '数量', money DECIMAL(11,0) DEFAULT NULL COMMENT '金额', status INT(1) DEFAULT NULL COMMENT '订单状态：0：创建中; 1：已完结' ) ENGINE=INNODB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8; SELECT * FROM t_order;

4.3.2 seata_storage库下建t_storage表

CREATE TABLE t_storage( id BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY, product_id BIGINT(11) DEFAULT NULL COMMENT '产品id', total INT(11) DEFAULT NULL COMMENT '总库存', used INT(11) DEFAULT NULL COMMENT '已用库存', residue INT(11) DEFAULT NULL COMMENT '剩余库存' ) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8; INSERT INTO seata_storage.t_storage(id,product_id,total,used,residue) VALUES('1','1','100','0','100'); SELECT * FROM t_storage;

4.3.3 seata_account库下建t_account表

CREATE TABLE t_account( id BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT 'id', user_id BIGINT(11) DEFAULT NULL COMMENT '用户id', total DECIMAL(10,0) DEFAULT NULL COMMENT '总额度', used DECIMAL(10,0) DEFAULT NULL COMMENT '已用余额', residue DECIMAL(10,0) DEFAULT '0' COMMENT '剩余可用额度' ) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8; INSERT INTO seata_account.t_account(id,user_id,total,used,residue) VALUES('1','1','1000','0','1000'); SELECT * FROM t_account;

4.4 按照上述3库分别建对应的回滚日志表

4.4.1 订单-库存-账户3个库下都需要建各自的回滚日志表

-- the table to store seata xid data -- 0.7.0+ add context -- you must to init this sql for you business databese. the seata server not need it. -- 此脚本必须初始化在你当前的业务数据库中，用于AT 模式XID记录。与server端无关（注：业务数据库） -- 注意此处0.3.0+ 增加唯一索引 ux_undo_log drop table `undo_log`; CREATE TABLE `undo_log` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `branch_id` bigint(20) NOT NULL, `xid` varchar(100) NOT NULL, `context` varchar(128) NOT NULL, `rollback_info` longblob NOT NULL, `log_status` int(11) NOT NULL, `log_created` datetime NOT NULL, `log_modified` datetime NOT NULL, `ext` varchar(100) DEFAULT NULL, PRIMARY KEY (`id`), UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

4.4.2 最终效果

五、订单/库存/账户业务微服务准备

5.1 业务需求

下订单->减库存->扣余额->改订单状态

5.2 新建订单Order-Module

5.2.1 建Module

seata-order-service2001

5.2.2 POM

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>cloud2020</artifactId> <groupId>com.atguigu.springcloud</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>seata-order-service2001</artifactId> <dependencies>  <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> </dependency>  <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-seata</artifactId> <exclusions> <exclusion> <artifactId>seata-all</artifactId> <groupId>io.seata</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>io.seata</groupId> <artifactId>seata-all</artifactId> <version>0.9.0</version> </dependency>  <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency>  <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency>  <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.37</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.0.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> </dependencies> </project>

5.2.3 YML

server: port: 2001 spring: application: name: seata-order-service cloud: alibaba: seata: #自定义事务组名称需要与seata-server中的对应 tx-service-group: fsp_tx_group nacos: discovery: server-addr: localhost:8848 datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/seata_order username: root password: root feign: hystrix: enabled: false logging: level: io: seata: info mybatis: mapperLocations: classpath:mapper/*.xml

5.2.4 file.conf

transport { # tcp udt unix-domain-socket type = "TCP" #NIO NATIVE server = "NIO" #enable heartbeat heartbeat = true #thread factory for netty thread-factory { boss-thread-prefix = "NettyBoss" worker-thread-prefix = "NettyServerNIOWorker" server-executor-thread-prefix = "NettyServerBizHandler" share-boss-worker = false client-selector-thread-prefix = "NettyClientSelector" client-selector-thread-size = 1 client-worker-thread-prefix = "NettyClientWorkerThread" # netty boss thread size,will not be used for UDT boss-thread-size = 1 #auto default pin or 8 worker-thread-size = 8 } shutdown { # when destroy server, wait seconds wait = 3 } serialization = "seata" compressor = "none" } service { vgroup_mapping.fsp_tx_group = "default" default.grouplist = "127.0.0.1:8091" enableDegrade = false disable = false max.commit.retry.timeout = "-1" max.rollback.retry.timeout = "-1" disableGlobalTransaction = false } client { async.commit.buffer.limit = 10000 lock { retry.internal = 10 retry.times = 30 } report.retry.count = 5 tm.commit.retry.count = 1 tm.rollback.retry.count = 1 } ## transaction log store store { ## store mode: file、db mode = "db" ## file store file { dir = "sessionStore" # branch session size , if exceeded first try compress lockkey, still exceeded throws exceptions max-branch-session-size = 16384 # globe session size , if exceeded throws exceptions max-global-session-size = 512 # file buffer size , if exceeded allocate new buffer file-write-buffer-cache-size = 16384 # when recover batch read size session.reload.read_size = 100 # async, sync flush-disk-mode = async } ## database store db { ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp) etc. datasource = "dbcp" ## mysql/oracle/h2/oceanbase etc. db-type = "mysql" driver-class-name = "com.mysql.jdbc.Driver" url = "jdbc:mysql://local:3306/seata" user = "root" password = "root" min-conn = 1 max-conn = 3 global.table = "global_table" branch.table = "branch_table" lock-table = "lock_table" query-limit = 100 } } lock { ## the lock store mode: local、remote mode = "remote" local { ## store locks in user's database } remote { ## store locks in the seata's server } } recovery { #schedule committing retry period in milliseconds committing-retry-period = 1000 #schedule asyn committing retry period in milliseconds asyn-committing-retry-period = 1000 #schedule rollbacking retry period in milliseconds rollbacking-retry-period = 1000 #schedule timeout retry period in milliseconds timeout-retry-period = 1000 } transaction { undo.data.validation = true undo.log.serialization = "jackson" undo.log.save.days = 7 #schedule delete expired undo_log in milliseconds undo.log.delete.period = 86400000 undo.log.table = "undo_log" } ## metrics settings metrics { enabled = false registry-type = "compact" # multi exporters use comma divided exporter-list = "prometheus" exporter-prometheus-port = 9898 } support { ## spring spring { # auto proxy the DataSource bean datasource.autoproxy = false } }

5.2.5 registry.conf

registry { # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa type = "nacos" nacos { serverAddr = "localhost:8848" namespace = "" cluster = "default" } eureka { serviceUrl = "http://localhost:8761/eureka" application = "default" weight = "1" } redis { serverAddr = "localhost:6379" db = "0" } zk { cluster = "default" serverAddr = "127.0.0.1:2181" session.timeout = 6000 connect.timeout = 2000 } consul { cluster = "default" serverAddr = "127.0.0.1:8500" } etcd3 { cluster = "default" serverAddr = "http://localhost:2379" } sofa { serverAddr = "127.0.0.1:9603" application = "default" region = "DEFAULT_ZONE" datacenter = "DefaultDataCenter" cluster = "default" group = "SEATA_GROUP" addressWaitTime = "3000" } file { name = "file.conf" } } config { # file、nacos 、apollo、zk、consul、etcd3 type = "file" nacos { serverAddr = "localhost" namespace = "" } consul { serverAddr = "127.0.0.1:8500" } apollo { app.id = "seata-server" apollo.meta = "http://192.168.1.204:8801" } zk { serverAddr = "127.0.0.1:2181" session.timeout = 6000 connect.timeout = 2000 } etcd3 { serverAddr = "http://localhost:2379" } file { name = "file.conf" } }

5.2.6 domain

package com.atguigu.springcloud.alibaba.domain; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; /** * @author by Jak * @date 2020/7/3 */ @Data @AllArgsConstructor @NoArgsConstructor public class CommonResult<T> { private Integer code; private String message; private T data; public CommonResult(Integer code, String message) { this(code, message, null); } } package com.atguigu.springcloud.alibaba.domain; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; import java.math.BigDecimal; @Data @AllArgsConstructor @NoArgsConstructor public class Order { private Long id; private Long userId; private Long productId; private Integer count; private BigDecimal money; private Integer status; //订单状态：0：创建中；1：已完结 }

5.2.7 Dao接口及实现

package com.atguigu.springcloud.alibaba.dao; import com.atguigu.springcloud.alibaba.domain.Order; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Param; /** * @author by Jak * @date 2020/7/3 */ @Mapper public interface OrderDao { //1 新建订单 void create(Order order); //2 修改订单状态，从零改为1 void update(@Param("userId") Long userId, @Param("status") Integer status); } <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.atguigu.springcloud.alibaba.dao.OrderDao"> <resultMap id="BaseResultMap" type="com.atguigu.springcloud.alibaba.domain.Order"> <id column="id" property="id" jdbcType="BIGINT"/> <result column="user_id" property="userId" jdbcType="BIGINT"/> <result column="product_id" property="productId" jdbcType="BIGINT"/> <result column="count" property="count" jdbcType="INTEGER"/> <result column="money" property="money" jdbcType="DECIMAL"/> <result column="status" property="status" jdbcType="INTEGER"/> </resultMap> <insert id="create"> insert into t_order (id,user_id,product_id,count,money,status) values (null,#{userId},#{productId},#{count},#{money},0); </insert> <update id="update"> update t_order set status = 1 where user_id=#{userId} and status = #{status}; </update> </mapper>

5.2.8 Service接口及实现

package com.atguigu.springcloud.alibaba.service; import com.atguigu.springcloud.alibaba.domain.Order; /** * @author by Jak * @date 2020/7/3 */ public interface OrderService { void create(Order order); } package com.atguigu.springcloud.alibaba.service.impl; import com.atguigu.springcloud.alibaba.dao.OrderDao; import com.atguigu.springcloud.alibaba.domain.Order; import com.atguigu.springcloud.alibaba.service.AccountService; import com.atguigu.springcloud.alibaba.service.OrderService; import com.atguigu.springcloud.alibaba.service.StorageService; import lombok.extern.slf4j.Slf4j; import org.springframework.stereotype.Service; import javax.annotation.Resource; /** * @author by Jak * @date 2020/7/3 */ @Service @Slf4j public class OrderServiceImpl implements OrderService { @Resource private OrderDao orderDao; @Resource private StorageService storageService; @Resource private AccountService accountService; /** * 创建订单->调用库存服务扣减库存->调用账户服务扣减账户余额->修改订单状态 * 简单说： * 下订单->减库存->减余额->该状态 * @param order */ @Override public void create(Order order) { //1 新建订单 log.info("----->开始新建订单"); orderDao.create(order); //2 扣减库存 log.info("----->订单微服务开始调用库存，做扣减Count"); storageService.decrease(order.getProductId(), order.getCount()); log.info("----->订单微服务开始调用库存，做扣减end"); //3 扣减账户 log.info("----->订单微服务开始调用账户，做扣减Money"); accountService.decrease(order.getUserId(), order.getMoney()); log.info("----->订单微服务开始调用账户，做扣减end"); //4 修改订单状态，从零到1代表已经完成 log.info("----->修改订单状态开始"); orderDao.update(order.getUserId(), 0); log.info("----->修改订单状态结束"); log.info("----->下订单结束了"); } } package com.atguigu.springcloud.alibaba.service; import com.atguigu.springcloud.alibaba.domain.CommonResult; import org.springframework.cloud.openfeign.FeignClient; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestParam; /** * @author by Jak * @date 2020/7/3 */ @FeignClient(value = "seata-storage-service") public interface StorageService { @PostMapping(value = "/storage/decrease") CommonResult decrease(@RequestParam("productId") Long productId, @RequestParam("count") Integer count); } package com.atguigu.springcloud.alibaba.service; import com.atguigu.springcloud.alibaba.domain.CommonResult; import org.springframework.cloud.openfeign.FeignClient; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestParam; import java.math.BigDecimal; /** * @author by Jak * @date 2020/7/3 */ @FeignClient(value = "seata-account-service") public interface AccountService { @PostMapping(value = "/account/decrease") CommonResult decrease(@RequestParam("userId") Long userId, @RequestParam("money")BigDecimal money); }

5.2.9 Controller

package com.atguigu.springcloud.alibaba.controller; import com.atguigu.springcloud.alibaba.domain.CommonResult; import com.atguigu.springcloud.alibaba.domain.Order; import com.atguigu.springcloud.alibaba.service.OrderService; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import javax.annotation.Resource; /** * @author by Jak * @date 2020/7/4 */ @RestController public class OrderController { @Resource private OrderService orderService; @GetMapping("/order/create") public CommonResult create(Order order) { orderService.create(order); return new CommonResult(200, "订单创建成功"); } }

5.2.10 Config配置

package com.atguigu.springcloud.alibaba.config; import org.mybatis.spring.annotation.MapperScan; import org.springframework.context.annotation.Configuration; @Configuration @MapperScan({"com.atguigu.springcloud.alibaba.dao"}) public class MyBatisConfig { } package com.atguigu.springcloud.alibaba.config; import com.alibaba.druid.pool.DruidDataSource; import io.seata.rm.datasource.DataSourceProxy; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.transaction.SpringManagedTransactionFactory; import org.springframework.beans.factory.annotation.Value; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import javax.sql.DataSource; @Configuration public class DataSourceProxyConfig { @Value("${mybatis.mapperLocations}") private String mapperLocations; @Bean @ConfigurationProperties(prefix = "spring.datasource") public DataSource druidDataSource(){ return new DruidDataSource(); } @Bean public DataSourceProxy dataSourceProxy(DataSource dataSource) { return new DataSourceProxy(dataSource); } @Bean public SqlSessionFactory sqlSessionFactoryBean(DataSourceProxy dataSourceProxy) throws Exception { SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean(); sqlSessionFactoryBean.setDataSource(dataSourceProxy); sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(mapperLocations)); sqlSessionFactoryBean.setTransactionFactory(new SpringManagedTransactionFactory()); return sqlSessionFactoryBean.getObject(); } }

5.2.11 主启动

package com.atguigu.springcloud.alibaba; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.openfeign.EnableFeignClients; @EnableDiscoveryClient @EnableFeignClients @SpringBootApplication(exclude = DataSourceAutoConfiguration.class)//取消数据源自动创建的配置 public class SeataOrderMainApp2001{ public static void main(String[] args) { SpringApplication.run(SeataOrderMainApp2001.class, args); } }

5.3 新建库存Storage-Module

5.3.1 seata-order-service2002

5.3.2 POM

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>cloud2020</artifactId> <groupId>com.atguigu.springcloud</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>seata-order-service2002</artifactId> <dependencies>  <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> </dependency>  <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-seata</artifactId> <exclusions> <exclusion> <artifactId>seata-all</artifactId> <groupId>io.seata</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>io.seata</groupId> <artifactId>seata-all</artifactId> <version>0.9.0</version> </dependency>  <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.0.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.37</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> </dependencies> </project>

5.3.3 YML

server: port: 2002 spring: application: name: seata-storage-service cloud: alibaba: seata: tx-service-group: fsp_tx_group nacos: discovery: server-addr: localhost:8848 datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/seata_storage username: root password: root logging: level: io: seata: info mybatis: mapperLocations: classpath:mapper/*.xml

5.3.4 file.conf

5.3.5 registry.conf

5.3.6 domain

package com.atguigu.springcloud.alibaba.domain; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; @Data @AllArgsConstructor @NoArgsConstructor public class CommonResult<T> { private Integer code; private String message; private T data; public CommonResult(Integer code, String message) { this(code,message,null); } } package com.atguigu.springcloud.alibaba.domain; import lombok.Data; @Data public class Storage { private Long id; // 产品id private Long productId; //总库存 private Integer total; //已用库存 private Integer used; //剩余库存 private Integer residue; }

5.3.7 Dao接口及实现

package com.atguigu.springcloud.alibaba.dao; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Param; @Mapper public interface StorageDao { //扣减库存信息 void decrease(@Param("productId") Long productId, @Param("count") Integer count); } <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.atguigu.springcloud.alibaba.dao.StorageDao"> <resultMap id="BaseResultMap" type="com.atguigu.springcloud.alibaba.domain.Storage"> <id column="id" property="id" jdbcType="BIGINT"/> <result column="product_id" property="productId" jdbcType="BIGINT"/> <result column="total" property="total" jdbcType="INTEGER"/> <result column="used" property="used" jdbcType="INTEGER"/> <result column="residue" property="residue" jdbcType="INTEGER"/> </resultMap> <update id="decrease"> UPDATE t_storage SET used = used + #{count},residue = residue - #{count} WHERE product_id = #{productId} </update> </mapper>

5.3.8 Service接口及实现

package com.atguigu.springcloud.alibaba.service; public interface StorageService { // 扣减库存 void decrease(Long productId, Integer count); } package com.atguigu.springcloud.alibaba.service.impl; import com.atguigu.springcloud.alibaba.dao.StorageDao; import com.atguigu.springcloud.alibaba.service.StorageService ; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Service; import javax.annotation.Resource; @Service public class StorageServiceImpl implements StorageService { private static final Logger LOGGER = LoggerFactory.getLogger(StorageServiceImpl.class); @Resource private StorageDao storageDao; // 扣减库存 @Override public void decrease(Long productId, Integer count) { LOGGER.info("------->storage-service中扣减库存开始"); storageDao.decrease(productId,count); LOGGER.info("------->storage-service中扣减库存结束"); } }

5.3.9 Controller

package com.atguigu.springcloud.alibaba.controller; import com.atguigu.springcloud.alibaba.domain.CommonResult ; import com.atguigu.springcloud.alibaba.service.StorageService ; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class StorageController { @Autowired private StorageService storageService; //扣减库存 @RequestMapping("/storage/decrease") public CommonResult decrease(Long productId, Integer count) { storageService.decrease(productId, count); return new CommonResult(200,"扣减库存成功！"); } }

5.3.10 Config配置

package com.atguigu.springcloud.alibaba.config; import org.mybatis.spring.annotation.MapperScan; import org.springframework.context.annotation.Configuration; @Configuration @MapperScan("com.atguigu.springcloud.alibaba.dao") public class MyBaitsConfig { } package com.atguigu.springcloud.alibaba.config; import com.alibaba.druid.pool.DruidDataSource; import io.seata.rm.datasource.DataSourceProxy; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.transaction.SpringManagedTransactionFactory; import org.springframework.beans.factory.annotation.Value; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import javax.sql.DataSource; @Configuration public class DataSourceProxyConfig { @Value("${mybatis.mapperLocations}") private String mapperLocations; @Bean @ConfigurationProperties(prefix = "spring.datasource") public DataSource druidDataSource(){ return new DruidDataSource(); } @Bean public DataSourceProxy dataSourceProxy(DataSource dataSource) { return new DataSourceProxy(dataSource); } @Bean public SqlSessionFactory sqlSessionFactoryBean(DataSourceProxy dataSourceProxy) throws Exception { SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean(); sqlSessionFactoryBean.setDataSource(dataSourceProxy); sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(mapperLocations)); sqlSessionFactoryBean.setTransactionFactory(new SpringManagedTransactionFactory()); return sqlSessionFactoryBean.getObject(); } }

5.3.11 主启动

package com.atguigu.springcloud.alibaba; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.openfeign.EnableFeignClients; @SpringBootApplication(exclude = DataSourceAutoConfiguration.class) @EnableDiscoveryClient @EnableFeignClients public class SeataStorageServiceApplication2002 { public static void main(String[] args) { SpringApplication.run(SeataStorageServiceApplication2002.class, args); } }

5.4 新建账户Account-Module

5.4.1 seata-order-service2003

5.4.2 POM

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>cloud2020</artifactId> <groupId>com.atguigu.springcloud</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>seata-order-service2003</artifactId> <dependencies>  <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> </dependency>  <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-seata</artifactId> <exclusions> <exclusion> <artifactId>seata-all</artifactId> <groupId>io.seata</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>io.seata</groupId> <artifactId>seata-all</artifactId> <version>0.9.0</version> </dependency>  <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.0.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.37</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> </dependencies> </project>

5.4.3 YML

server: port: 2003 spring: application: name: seata-account-service cloud: alibaba: seata: tx-service-group: fsp_tx_group nacos: discovery: server-addr: localhost:8848 datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/seata_account username: root password: root feign: hystrix: enabled: false logging: level: io: seata: info mybatis: mapperLocations: classpath:mapper/*.xml

5.4.4 file.conf

5.4.5 registry.conf

5.4.6 domain

package com.atguigu.springcloud.alibaba.domain; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; @Data @AllArgsConstructor @NoArgsConstructor public class CommonResult<T> { private Integer code; private String message; private T data; public CommonResult(Integer code, String message) { this(code,message,null); } } package com.atguigu.springcloud.alibaba.domain; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; import java.math.BigDecimal; @Data @AllArgsConstructor @NoArgsConstructor public class Account { private Long id; /** * 用户id */ private Long userId; /** * 总额度 */ private BigDecimal total; /** * 已用额度 */ private BigDecimal used; /** * 剩余额度 */ private BigDecimal residue; }

5.4.7 Dao接口及实现

package com.atguigu.springcloud.alibaba.dao; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Param; import java.math.BigDecimal; @Mapper public interface AccountDao { /** * 扣减账户余额 */ void decrease(@Param("userId") Long userId, @Param("money") BigDecimal money); } <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.atguigu.springcloud.alibaba.dao.AccountDao"> <resultMap id="BaseResultMap" type="com.atguigu.springcloud.alibaba.domain.Account"> <id column="id" property="id" jdbcType="BIGINT"/> <result column="user_id" property="userId" jdbcType="BIGINT"/> <result column="total" property="total" jdbcType="DECIMAL"/> <result column="used" property="used" jdbcType="DECIMAL"/> <result column="residue" property="residue" jdbcType="DECIMAL"/> </resultMap> <update id="decrease"> UPDATE t_account SET residue = residue - #{money},used = used + #{money} WHERE user_id = #{userId}; </update> </mapper>

5.4.8 Service接口及实现

package com.atguigu.springcloud.alibaba.service; import org.springframework.web.bind.annotation.RequestParam; import java.math.BigDecimal; public interface AccountService { /** * 扣减账户余额 */ void decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money); } package com.atguigu.springcloud.alibaba.service.impl; import com.atguigu.springcloud.alibaba.dao.AccountDao; import com.atguigu.springcloud.alibaba.service.AccountService ; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Service; import javax.annotation.Resource; import java.math.BigDecimal; import java.util.concurrent.TimeUnit; /** * 账户业务实现类 */ @Service public class AccountServiceImpl implements AccountService { private static final Logger LOGGER = LoggerFactory.getLogger(AccountServiceImpl.class); @Resource AccountDao accountDao; /** * 扣减账户余额 */ @Override public void decrease(Long userId, BigDecimal money) { LOGGER.info("------->account-service中扣减账户余额开始"); try { TimeUnit.SECONDS.sleep(20); } catch (InterruptedException e) { e.printStackTrace(); } accountDao.decrease(userId,money); LOGGER.info("------->account-service中扣减账户余额结束"); } }

5.4.9 Controller

package com.atguigu.springcloud.alibaba.controller; import com.atguigu.springcloud.alibaba.domain.CommonResult ; import com.atguigu.springcloud.alibaba.service.AccountService ; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import javax.annotation.Resource; import java.math.BigDecimal; @RestController public class AccountController { @Resource AccountService accountService; /** * 扣减账户余额 */ @RequestMapping("/account/decrease") public CommonResult decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money){ accountService.decrease(userId,money); return new CommonResult(200,"扣减账户余额成功！"); } }

5.4.10 Config配置

5.4.11 主启动

package com.atguigu.springcloud.alibaba; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.openfeign.EnableFeignClients; @SpringBootApplication(exclude = DataSourceAutoConfiguration.class) @EnableDiscoveryClient @EnableFeignClients public class SeataAccountMainApp2003 { public static void main(String[] args) { SpringApplication.run(SeataAccountMainApp2003.class, args); } }

六、测试

6.1 业务需求

下订单->减库存->扣余额->改(订单)状态

6.2 数据库初始化情况

6.3 正常下单

http://localhost:2001/order/create?userId=1&producrId=1&count=10&money=100

6.3.1 数据库情况

6.4 超时异常，没加@GlobalTransactional

6.4.1 AccountServiceImpl添加超时

6.4.2 数据库情况

订单状态不OK，但是被扣钱了

6.4.3 故障情况

当库存和账户余额扣减后，订单状态并没有设置为已经完成，没有从零改为1，而且由于feign的重试机制，账户余额还有可能被多次扣减。

6.5 超时异常，添加@GlobalTransactional

AccountServiceImpl添加超时

OrderServiceImpl @GlobalTransactional

下单后数据库数据并没有任何改变

记录都添加不进来

select * from t_order

七、Seata之原理简介

7.1 Seata

2019年1月份蚂蚁金服和阿里巴巴共同开源的分布式事务解决方案，Simple Extensible Autonomous Transaction Architecture，简单可扩展自治事务框架,2020起初，参加工作后用1.0以后的版本.

7.2 TC/TM/RM三大组件

7.2.1 分布式事务的执行流程

TM开启分布式事务(TM向TC注册全局事务记录)换业务场景，编排数据库，服务等事务内资源(RM向TC汇报资源准备状态)TM结束分布式事务，事务一阶段结束(TM通知TC提交/回滚分布式事务)TC汇总事务信息，决定分布式事务是提交还是回滚TC通知所有RM提交/回滚资源，事务二阶段结束

7.3 AT模式如何做到对业务的无侵入

7.3.1 是什么

Seata是一款开源的分布式事务解决方案，致力于提供高性能和简单易用的分布式事务服务。Seata将为用户提供了AT、TCC、SAGA和XA事务模式，为用户打造一站式的分布式解决方案。

AT模式

前提

基于支持本地ACID事务的关系型数据库

Java应用，通过JDBC访问数据库

整体机制

两阶段提交协议的演变：

一阶段：业务数据和回滚日志记录在同一个本地事务中提交，释放本地锁和连接资源。二阶段：提交异步化，非常快速的完成。回滚通过一阶段的回滚日志进行反向补偿

7.3.2 一阶段加载

7.3.3 二阶段提交

二阶段如果顺利提交的话，因为“业务SQL”在一阶段已经提交至数据库，所以Seata框架只需将一阶段保存的快照数据和行锁删掉，完成数据清理即可。

7.3.4 二阶段回滚

Processed: 0.012, SQL: 9