SpringCloud Alibaba Seata处理分布式事务
分布式事务问题
分布式前
单机库存没这个问题
O(∩_∩)O
从1:1->1:N->N:N
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。
一句话
一次业务操作需要垮多个数据源或需要垮多个系统进行远程调用,就会产生分布式事务问题
Seata简介
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/
能干嘛
一个典型的分布式事务过程
分布式事务处理过程-ID+三组件模型
Transaction ID(XID)
全局唯一的事务id
三组件概念
- 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,并接受事务协调的指令,驱动分支(本地)事务的提交和回滚
处理过程
在哪下
发布说明: https://github.com/seata/seata/releases
怎么玩
本地@Transational
全局@GlobalTranstional
seata的分布式交易解决方案
Seata-Server安装
1.官网地址
https://seata.io/zh-cn/
2.下载版本
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
file.conf
service模块
store模块
4.mysql5.7数据库新建库seata
5.在seata库里新建表
建表db_store.sql在seata-server-0.9.0seataconf目录里面
db_store.sql
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`)
);6.修改seata-server-0.9.0seataconf目录下的registry.conf目录下的registry.conf配置文件
7.先启动Nacos端口号8848
8.再启动seata-server
seata-server-0.9.0seatain
seata-server.bat
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
分布式事务业务说明
这里我们会创建三个服务, 一个订单服务, 一个库存服务, 一个账户服务。
当用户下单时，会在订单服务中创建一个订单 ,然后通过远程调用库存服务来扣减下单商品的库存,
再通过远程调用账户服务来扣减用户账户里面的余额,
最后在订单服务中修改订单状态为已完成。
该操作跨越三个数据库，有两次远程调用，很明显会有分布式事务问题。
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;按照上述3库分别建立对应业务表
seata_order库下新建t_order表
DROP TABLE IF EXISTS `t_order`;
CREATE TABLE `t_order` (
`int` bigint(11) NOT NULL AUTO_INCREMENT,
`user_id` bigint(20) 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',
PRIMARY KEY (`int`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci COMMENT = '订单表' ROW_FORMAT = Dynamic;seata_storage库下新建t_storage表
DROP TABLE IF EXISTS `t_storage`;
CREATE TABLE `t_storage` (
`int` bigint(11) NOT NULL AUTO_INCREMENT,
`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',
PRIMARY KEY (`int`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci COMMENT = '库存' ROW_FORMAT = Dynamic;
INSERT INTO `t_storage` VALUES (1, 1, 100, 0, 100);seata_account库下新建t_account表
CREATE TABLE `t_account` (
`id` bigint(11) NOT NULL 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 NULL COMMENT '剩余可用额度',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci COMMENT = '账户表' ROW_FORMAT = Dynamic;
INSERT INTO `t_account` VALUES (1, 1, 1000, 0, 1000);按照上述3库分别建立对应的回滚日志表
订单-库存-账户3个库下都需要建各自独立的回滚日志表
seata-server-0.9.0seataconf目录下的db_undo_log.sql
建表SQL
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;最终效果
订单/库存/账户业务微服务准备
业务需求
下订单->减库存->扣余额->改(订单)状态
新建订单Order-Module
1.seata-order-service2001
2.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>
<groupId>io.seata</groupId>
<artifactId>seata-all</artifactId>
</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.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!--jdbc-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!--hutool 测试雪花算法-->
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-captcha</artifactId>
<version>5.2.0</version>
</dependency>
</dependencies>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: 127.0.0.1:8848
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.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/seata_order?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
username: root
password: root
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath*:mapper/*.xml4.file.conf
就是seata文件夹下的file.conf
拷贝seata-server/conf目录下的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->rgroup
# 事务组名称
vgroup_mapping.fsp_tx_group = "default"
#only support single node
default.grouplist = "127.0.0.1:8091"
#degrade current not support
enableDegrade = false
#disable
disable = false
#unit ms,s,m,h,d represents milliseconds, seconds, minutes, hours, days, default permanent
max.commit.retry.timeout = "-1"
max.rollback.retry.timeout = "-1"
}
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 = "file"
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://127.0.0.1:3306/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.registry.conf
拷贝seata-server/conf目录下的registry.conf
registry {
# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
type = "nacos"
nacos {
#serverAddr = "localhost"
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"
}
}6.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);
}
}Order
7.Dao接口实现
OrderDao
@Mapper
public interface OrderDao {
/**
* 1 新建订单
* @param order
* @return
*/
int create(Order order);
/**
* 2 修改订单状态,从0改为1
* @param userId
* @param status
* @return
*/
int update(@Param("userId") Long userId, @Param("status") Integer status);
}resources文件夹下新建mapper文件夹后添加
<?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.eiletxie.springcloud.alibaba.dao.OrderDao">
<resultMap id="BaseResultMap" type="com.eiletxie.springcloud.alibaba.domain.Order">
<id column="id" property="id" jdbcType="BIGINT"></id>
<result column="user_id" property="userId" jdbcType="BIGINT"></result>
<result column="product_id" property="productId" jdbcType="BIGINT"></result>
<result column="count" property="count" jdbcType="INTEGER"></result>
<result column="money" property="money" jdbcType="DECIMAL"></result>
<result column="status" property="status" jdbcType="INTEGER"></result>
</resultMap>
<insert id="create" parameterType="com.eiletxie.springcloud.alibaba.domain.Order" useGeneratedKeys="true"
keyProperty="id">
insert into t_order(user_id,product_id,count,money,status) values (#{userId},#{productId},#{count},#{money},0);
</insert>
<update id="update">
update t_order set status =1 where user_id =#{userId} and status=#{status};
</update>
</mapper>OrderMapper.xml
8.Service接口及实现
OrderService
public interface OrderService {
/**
* 创建订单
* @param order
*/
void create(Order order);
}@Service
@Slf4j
public class OrderServiceImpl implements OrderService {
@Resource
private OrderDao orderDao;
@Resource
private AccountService accountService;
@Resource
private StorageService storageService;
/**
* 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->改状态
* GlobalTransactional seata开启分布式事务,异常时回滚,name保证唯一即可
* @param order 订单对象
*/
@Override
///@GlobalTransactional(name = "fsp-create-order", rollbackFor = Exception.class)
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0到1,1代表已完成
log.info("----->修改订单状态开始");
orderDao.update(order.getUserId(), 0);
log.info("----->下订单结束了,O(∩_∩)O哈哈~");
}
}AccountService
@FeignClient(value = "seata-account-service")
public interface AccountService {
/**
* 减余额
* @param userId
* @param money
* @return
*/
@PostMapping(value = "/account/decrease")
CommonResult decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money);
}StorageService
@FeignClient(value = "seata-storage-service")
public interface StorageService {
/**
* 减库存
* @param productId
* @param count
* @return
*/
@PostMapping(value = "/storage/decrease")
CommonResult decrease(@RequestParam("productId") Long productId, @RequestParam("count") Integer count);
}9.Controller
OrderController
@RestController
public class OrderController {
@Resource
private OrderService orderService;
/**
* 创建订单
*
* @param order
* @return
*/
@GetMapping("/order/create")
public CommonResult create(Order order) {
orderService.create(order);
return new CommonResult(200, "订单创建成功");
}
}10.Config配置
MyBatisConfig
@Configuration
@MapperScan({"com.eiletxie.springcloud.alibaba.dao"})
public class MyBatisConfig {
}DataSourceProxyConfig
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.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 org.springframework.core.io.support.ResourcePatternResolver;
import javax.sql.DataSource;
/**
* @Author EiletXie
* @Since 2020/3/18 21:51
* 使用Seata对数据源进行代理
*/
@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 druidDataSource) {
return new DataSourceProxy(druidDataSource);
}
@Bean
public SqlSessionFactory sqlSessionFactoryBean(DataSourceProxy dataSourceProxy) throws Exception {
SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
bean.setDataSource(dataSourceProxy);
ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
bean.setMapperLocations(resolver.getResources(mapperLocations));
return bean.getObject();
}
}11.主启动
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class) //取消数据源的自动创建
@EnableDiscoveryClient
@EnableFeignClients
public class SeataOrderMain2001 {
public static void main(String[] args) {
SpringApplication.run(SeataOrderMain2001.class,args);
}
}新建库存Storage-Module
1、seata-storage-service2002
基本和2001一样，除了dao层和mapper有点区别
2、POM
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:
type: com.alibaba.druid.pool.DruidDataSource
# mysql驱动类
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/seata_storage?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
username: root
password: root
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath*:mapper/*.xml4、file.conf
5、registry.conf
6、domain
CommonResult
和2001一样
Storage
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Storage {
private Long id;
private Integer total;
private Integer used;
private Integer residue;
}7、Dao接口及实现
StorageDao
@Mapper
public interface StorageDao {
void decrease(@Param("productId") Long productId,@Param("count") Integer count);
}resources文件夹下新建mapper文件夹后添加
<?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.eiletxie.springcloud.alibaba.dao.StorageDao">
<resultMap id="BaseResultMap" type="com.eiletxie.springcloud.alibaba.domain.Storage">
<id column="id" property="id" jdbcType="BIGINT"></id>
<result column="product_id" property="productId" jdbcType="BIGINT"></result>
<result column="total" property="total" jdbcType="INTEGER"></result>
<result column="used" property="used" jdbcType="INTEGER"></result>
<result column="residue" property="residue" jdbcType="INTEGER"></result>
</resultMap>
<update id="decrease">
update t_storage
set used = used + #{count},residue = residue - #{count}
where product_id= #{productId};
</update>
</mapper>8、Service接口及实现
StorageService
public interface StorageService {
void decrease(Long productId, Integer count);
}StorageServiceImpl
@Service
public class StorageServiceImpl implements StorageService {
private static final Logger LOGGER = LoggerFactory.getLogger(StorageServiceImpl.class);
@Resource
private StorageDao storageDao;
@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");
}
}9、Controller
StorageController
@RestController
public class StorageController {
@Resource
private StorageService storageService;
@RequestMapping("/storage/decrease")
public CommonResult decrease(Long productId,Integer count) {
storageService.decrease(productId, count);
return new CommonResult(200,"扣减库存成功!");
}
}10、Config配置
和2001一样
11、主启动
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableFeignClients
@EnableDiscoveryClient
public class SeataStorageMain2002 {
public static void main(String[] args) {
SpringApplication.run(SeataStorageMain2002.class,args);
}
}新建账户Account-Module
1、seata-account-service2003
6、domain
CommonResult
和2001一样
Account
7、Dao接口及实现
AccountDao
@Mapper
public interface AccountDao {
/**
* 扣减账户余额
* @param userId
* @param money
*/
void decrease(@Param("userId") Long userId, @Param("money") BigDecimal money);
}resources文件夹下新建mapper文件夹后添加
<?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.eiletxie.springcloud.alibaba.dao.AccountDao">
<resultMap id="BaseResultMap" type="com.eiletxie.springcloud.alibaba.domain.Account">
<id column="id" property="id" jdbcType="BIGINT"></id>
<result column="user_id" property="userId" jdbcType="BIGINT"></result>
<result column="total" property="total" jdbcType="DECIMAL"></result>
<result column="used" property="used" jdbcType="DECIMAL"></result>
<result column="residue" property="residue" jdbcType="DECIMAL"></result>
</resultMap>
<update id="decrease">
update t_account
set used = used + #{money},residue = residue - #{money}
where user_id= #{userId};
</update>
</mapper>8、Service接口及实现
AccountService
public interface AccountService {
void decrease(Long userId, BigDecimal money);
}AccountServiceImpl
@Service
public class AccountServiceImpl implements AccountService {
private static final Logger LOGGER = LoggerFactory.getLogger(AccountServiceImpl.class);
@Resource
private AccountDao accountDao;
@Override
public void decrease(Long userId, BigDecimal money) {
LOGGER.info("----> account-service中扣减用户余额开始");
accountDao.decrease(userId,money);
LOGGER.info("----> account-service中扣减用户余额开始");
}
}9、Controller
AccountController
@RestController
public class AccountController {
@Resource
AccountService accountService;
@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！");
}
}11、主启动
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableFeignClients
@EnableDiscoveryClient
public class SeataAccountMain2003 {
public static void main(String[] args) {
SpringApplication.run(SeataAccountMain2003.class,args);
}
}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:
type: com.alibaba.druid.pool.DruidDataSource
# mysql驱动类
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/seata_account?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
username: root
password: root
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath*:mapper/*.xmlTest
数据库初始情况
下订单->减库存->扣余额->改订单状态
正常下单
http://localhost:2001/order/create?userId=1&productId=1&count=10&money=100
数据库情况
超时异常，没加@GlobalTransational
- AccountServiceImpl添加超时
- 数据库情况
- 故障情况
- 当库存和账户金额扣减后，订单状态并没有设置为依据完成，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
超时异常，添加@GlobalTransational
结果
各数据库无记录新增
OrderServiceImpl
@Override
@GlobalTransactional(name = "fsp-create-order",rollbackFor = Exception.class)
///@GlobalTransactional(name = "fsp-create-order", rollbackFor = Exception.class)
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0到1,1代表已完成
log.info("----->修改订单状态开始");
orderDao.update(order.getUserId(), 0);
log.info("----->下订单结束了,O(∩_∩)O哈哈~");
}一部分补充
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起始，参加工作后使用1.0以后的版本
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）
- 按业务场景，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
AT模式如何做到对业务的无侵入
是什么
一阶段加载
二阶段提交
二阶段回滚
debug
AccountServiceImpl
undo.log
before image
补充
