SpringCloud Alibaba Seata处理分布式事务
SpringCloud Alibaba Seata处理分布式事务
OY
发布于 2022-03-17 19:34:03
发布于 2022-03-17 19:34:03
SpringCloud Alibaba Seata 处理分布式事务
一、分布式事务问题
① 分布式前
单机单库没这个问题 从 1： 1 -> 1:N -> N: N
② 分布式之后
单体应用被拆分成微服务应用， 原来的三个模块被拆分成三个独立的应用，分别使用三个独立的数据源。
业务操作需要调用三个服务来完成。 此时每个服务内部的数据一致性由本地事务来保证， 但是全局的数据一致性问题没法保证。
③ 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
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
官网地址 http://seata.io/zh-cn/
② 能干嘛
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；
- 处理过程
- 去哪下 发布说明: https://github.com/seata/seata/releases
- 怎么玩
- Spring 本地@Transactional
- 全局@GlobalTransactional
三、Seata-Server 安装
① 官网地址
http://seata.io/zh-cn/② 下载版本
③ 修改配置文件
- 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.fsp_tx_group = "default"
- store 模块
mode = "db"
url = "jdbc:mysql://127.0.0.1:3306/seata"
user = "root"
password = "你自己的密码"
④ mysql5.7 数据库新建库 seata
create database seata;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.sq
-- 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`)
);⑥ 修 改 seata-server-0.9.0\seata\conf 目 录 下 的 registry.conf 配置文件 、
registry {
# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
type = "nacos"
nacos {
serverAddr = "localhost:8848"
namespace = ""
cluster = "default"
}
==目的是==： 指明注册中心为 nacos， 及修改 nacos 连接信息
⑦ 先启动 Nacos 端口号 8848
⑧ 再启动 seata-server
- seata-server.bat
四、订单/库存/账户业务数据库准备
① 以下演示都需要先启动 Nacos 后启动 Seata， 保证两个都 OK
② 分布式事务业务说明
==业务说明==
下订单–>扣库存–>减账户（ 余额）
③ 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
建表 SQL
CREATE DATABASE seata_order；
CREATE DATABASE seata_storage；
CREATE DATABASE seata_account;④ 按照上述 3 库分别建对应业务表
- 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;- 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 t_storage(`id`,`product_id`,`total`,`used`,`residue`)VALUES('1','1','100','0','100');
SELECT * FROM t_storage;- 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;⑤ 按照上述 3 库分别建对应的回滚日志表
- 订单-库存-账户 3 个库下都需要建各自的回滚日志表
- \seata-server-0.9.0\seata\conf 目录下的 db_undo_log.sql
建表 SQL
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;⑥ 最终效果
五、订单/库存/账户业务微服务准备
1. 业务需求
- 下订单->减库存->扣余额->改（订单） 状态
2. 新建订单 Order-Module
建 Module : seata-order-service2001
POM
<dependencies>
<!--nacos-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<!--seata-->
<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>
<!--feign-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<!--web-actuator-->
<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>
<!--mysql-druid-->
<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>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:
# 当前数据源操作类型
type: com.alibaba.druid.pool.DruidDataSource
# mysql驱动类
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/seata_order
username: root
password: 6090
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapper-locations: classpath:mapper/*.xmlfile.conf
拷贝 seata-server/conf 目录下的 file.conf 到项目 resources 里面
registry.conf
拷贝 seata-server/conf 目录下的 registry.conf 到项目 resources 里面
domain
- CommonResult
@Data
@AllArgsConstructor
@NoArgsConstructor
public class CommonResult<T>{
private Integer code;
private String message;
private T date;
public CommonResult(Integer code, String message){
this(code, message,null);
}
}- Order
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Order {
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
}Dao 接口及实现
- OrderDao
@Mapper
public interface OrderDao {
// 新建订单
void create(Order order);
// 修改订单状态，从零开始
void update(@Param("userId")Long userId, @Param("status") Integer status);
}- resources 文 件 夹 下 新 建 mapper 文 件 夹 后 添 加 OrderMapper.xml
<?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.oy.springcloud.dao.OrderDao">
<resultMap id="BaseResultMap" type="com.oy.springcloud.domain.Order">
<id column="id" property="id" jdbcType="BIGINT"></id>
<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>
<!-- void create(Order order);-->
<insert id="create">
insert into t_order(id,user_id, product_id, count, money,status) values(null,#{userId},#{productId},#{count},#{money},0);
</insert>
<!-- void update(@Param("useId")Long userId, @Param("status") Integer status);-->
<update id="update">
update t_order set status = 1 where user_id=#{userId} and status = #{status};
</update>
</mapper>Service 接口及实现
- OrderService
public interface OrderService {
void create(Order order);
}- OrderServiceImpl
@Service
@Slf4j
public class OrderServiceImpl implements OrderService {
@Resource
private OrderDao orderDao;
@Resource
private StorageService storageService;
@Resource
private AccountService accountService;
@Override
@GlobalTransactional(name = "fsp-create-order",rollbackFor = Exception.class)
public void create(Order order) {
log.info("----->开始新建订单");
//新建订单
orderDao.create(order);
//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");
//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");
//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");
}
}- StorageService
@FeignClient(value = "seata-storage-service")
public interface StorageService {
@PostMapping(value = "/storage/decrease")
CommonResult decrease(@RequestParam("productId") Long productId, @RequestParam("count") Integer count);
}- AccountService
@FeignClient(value = "seata-account-service")
public interface AccountService {
@PostMapping(value = "/account/decrease")
CommonResult decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money);
}Controller
@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");
}
}Config 配置
- MyBatisConfig
@Configuration
@MapperScan({"com.oy.springcloud.dao"})
public class MyBatisConfig {
}- DataSourceProxyConfig
package com.oy.springcloud.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();
}
}主启动
@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);
}
}3.新建库存 Storage-Module
**seata-order-service2002 **
POM
<dependencies>
<!--nacos-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<!--seata-->
<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>
<!--feign-->
<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>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: 123456
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath:mapper/*.xmlfile.conf
registry.conf
- 拷贝 seata-server/conf 目录下的file.conf 、registry.conf 到项目 resources 里面
domain
- CommonResult
@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);
}
}- Storage
@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;
}Dao 接口及实现
- StorageDao
@Mapper
public interface StorageDao {
/**
* 扣减库存信息
*/
void decrease(@Param("productId")Long productId, @Param("count") Integer count);
}- resources 文 件 夹 下 新 建 mapper 文 件 夹 后 添 加 StorageMapper.xml
<?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.oy.springcloud.dao.StorageDao">
<resultMap id="BaseResultMap" type="com.oy.springcloud.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>
<!--void decrease(@Param("productId")Long productId, @Param("count") Integer count);-->
<update id="decrease">
UPDATE t_storage SET used = used + #{count}, residue = residue - #{count} WHERE product_id = #{productId}
</update>
</mapper>Service 接口及实现
- StorageService
public interface StorageService {
/**
* 扣减库存
*/
void decrease(Long productId, Integer count);
}- StorageServiceImpl
@Service
@Slf4j
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");
}
}Controller
@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！ ");
}
}Config 配置
- MyBatisConfig
@Configuration
@MapperScan({"com.oy.springcloud.dao"})
public class MyBatisConfig {
}- DataSourceProxyConfig
package com.oy.springcloud.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;
/**
* @Author OY
* @Date 2020/11/16
*/
@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();
}
}主启动
@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class SeataStorageServiceApplication2002 {
public static void main(String[] args) {
SpringApplication.run(SeataStorageServiceApplication2002.class, args);
}
}4.新建账户 Account-Module
seata-account-service2003
POM
<dependencies>
<!--nacos-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<!--seata-->
<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>
<!--feign-->
<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>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: 6090
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath:mapper/*.xmlfile.conf registry.conf
domain
- CommonResult
@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);
}
}- Account
@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;
}Dao 接口及实现
- AccountDao
@Mapper
public interface AccountDao {
/**
* 扣减账户余额
*/
void decrease(@Param("userId") Long userId, @Param("money") BigDecimal money);
}- resources 文 件 夹 下 新 建 mapper 文 件 夹 后 添 加 AccountMapper.xml
<?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.oy.springcloud.dao.AccountDao">
<resultMap id="BaseResultMap"
type="com.oy.springcloud.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>Service 接口及实现
- AccountService
public interface AccountService {
/**
* 扣减账户余额
*/
void decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money);
}- AccountServiceImpl
public class AccountServiceImpl implements AccountService {
private static final Logger LOGGER = LoggerFactory.getLogger(AccountServiceImpl.class);
@Resource
AccountDao accountDao;
@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");
}
}Controller
@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！ ");
}
}Config 配置
- MyBatisConfig
@Configuration
@MapperScan({"com.oy.springcloud.dao.AccountDao"})
public class MyBatisConfig {
}- DataSourceProxyConfig
package com.oy.springcloud.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();
}
}主启动
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableDiscoveryClient
@EnableFeignClients
public class SeataAccountMainApp2003 {
public static void main(String[] args) {
SpringApplication.run(SeataAccountMainApp2003.class, args);
}
}注意：如果报错 A component required a bean of type 'com.oy.springcloud.dao.AccountDao' that could not be found.
请在启动类上加：
六、Test
① 下订单->减库存->扣余额->改（订单） 状态
我们只需要使用一个 @GlobalTransactional 注解在业务方法上；
② 数据库初始化情况
③ 正常下单
- http://localhost:2001/order/create?userId=1&producId=1&count=10&money=100
数据库情况
④ 超时异常， 没加@GlobalTransactional
AccountServiceImpl 添加超时
- 数据库情况 余额和库存都已经扣除，但是订单状态还是未支付，结果就是，这个订单仍要再次支付
- 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
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
七、Seata 之原理简介
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
② 再看 TC/TM/RM 三大组件
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 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 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
③ AT 模式如何做到对业务的无侵入
- 一阶段加载
- 二阶段提交
- 二阶段回滚
④ 补充
本文参与 腾讯云自媒体同步曝光计划，分享自作者个人站点/博客。
原始发表：2020-11-17，如有侵权请联系 cloudcommunity@tencent.com 删除
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