分布式事务问题由来
分布式前
- 单机单库没这个问题
- 从1:1 -> 1:N -> N:N
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。
Seata术语
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。
官方网址
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一ID 三组件模型：
- Transaction ID XID 全局唯一的事务ID
- 三组件概念
- TC (Transaction Coordinator) - 事务协调者：维护全局和分支事务的状态，驱动全局事务提交或回滚。
- TM (Transaction Manager) - 事务管理器：定义全局事务的范围：开始全局事务、提交或回滚全局事务。
- RM (Resource Manager) - 资源管理器：管理分支事务处理的资源，与TC交谈以注册分支事务和报告分支事务的状态，并驱动分支事务提交或回滚。
处理过程：
- TM向TC申请开启一个全局事务，全局事务创建成功并生成一个全局唯一的XID；
- XID在微服务调用链路的上下文中传播；
- RM向TC注册分支事务，将其纳入XID对应全局事务的管辖；
- TM向TC发起针对XID的全局提交或回滚决议；
- TC调度XID下管辖的全部分支事务完成提交或回滚请求。
Seata-Server安装
去哪下
发布说明: https://github.com/seata/seata/releases
怎么玩
本地@Transactional
全局@GlobalTransactional
SEATA 的分布式交易解决方案
我们只需要使用一个 @GlobalTransactional 注解在业务方法上:
Seata-Server安装
官网地址 - http://seata.io/zh-cn/
下载版本 - 1.5.2
当前是20220831，最新版本为 - 1.5.2
seata-server-1.5.2.zip解压到指定目录
进入 cd seata
进入 cd conf
修改 application.yml： vim application.yml 注意替换自己的 nacos地址
代码语言：javascript复制server:
port: 7091
spring:
application:
name: seata-server
logging:
config: classpath:logback-spring.xml
file:
path: ${user.home}/logs/seata
#extend:
# logstash-appender:
# destination: 127.0.0.1:4560
#kafka-appender:
# bootstrap-servers: 127.0.0.1:9092
#topic: logback_to_logstash
console:
user:
username: seata
password: seata
seata:
config:
# support: nacos, consul, apollo, zk, etcd3
type: nacos
nacos:
server-addr: 127.0.0.1:1111
namespace:
group: SEATA_GROUP
username: nacos
password: nacos
data-id: seataServer.properties
registry:
# support: nacos, eureka, redis, zk, consul, etcd3, sofa
type: nacos
nacos:
application: seata-server
server-addr: 127.0.0.1:1111
group: SEATA_GROUP
namespace:
cluster: default
username: nacos
password: nacos
# store:
# support: file 、 db 、 redis
# mode: file
# server:
# service-port: 8091 #If not configured, the default is '${server.port} 1000'
security:
secretKey: SeataSecretKey0c382ef121d778043159209298fd40bf3850a017
tokenValidityInMilliseconds: 1800000
ignore:
urls: /,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*.png,/**/*.ico,/console-fe/public/**,/api/v1/auth/login
进入 /usr/local/project/seata/script/config-center
修改 vim config.txt 注意
代码语言：javascript复制#For details about configuration items, see https://seata.io/zh-cn/docs/user/configurations.html
#Transport configuration, for client and server
transport.type=TCP
transport.server=NIO
transport.heartbeat=true
transport.enableTmClientBatchSendRequest=false
transport.enableRmClientBatchSendRequest=true
transport.enableTcServerBatchSendResponse=false
transport.rpcRmRequestTimeout=30000
transport.rpcTmRequestTimeout=30000
transport.rpcTcRequestTimeout=30000
transport.threadFactory.bossThreadPrefix=NettyBoss
transport.threadFactory.workerThreadPrefix=NettyServerNIOWorker
transport.threadFactory.serverExecutorThreadPrefix=NettyServerBizHandler
transport.threadFactory.shareBossWorker=false
transport.threadFactory.clientSelectorThreadPrefix=NettyClientSelector
transport.threadFactory.clientSelectorThreadSize=1
transport.threadFactory.clientWorkerThreadPrefix=NettyClientWorkerThread
transport.threadFactory.bossThreadSize=1
transport.threadFactory.workerThreadSize=default
transport.shutdown.wait=3
transport.serialization=seata
transport.compressor=none
#Transaction routing rules configuration, only for the client
service.vgroupMapping.my_tx_group=default
#If you use a registry, you can ignore it
service.default.grouplist=10.211.55.5:8091
service.enableDegrade=false
service.disableGlobalTransaction=false
#Transaction rule configuration, only for the client
client.rm.asyncCommitBufferLimit=10000
client.rm.lock.retryInterval=10
client.rm.lock.retryTimes=30
client.rm.lock.retryPolicyBranchRollbackOnConflict=true
client.rm.reportRetryCount=5
client.rm.tableMetaCheckEnable=true
client.rm.tableMetaCheckerInterval=60000
client.rm.sqlParserType=druid
client.rm.reportSuccessEnable=false
client.rm.sagaBranchRegisterEnable=false
client.rm.sagaJsonParser=fastjson
client.rm.tccActionInterceptorOrder=-2147482648
client.tm.commitRetryCount=5
client.tm.rollbackRetryCount=5
client.tm.defaultGlobalTransactionTimeout=60000
client.tm.degradeCheck=false
client.tm.degradeCheckAllowTimes=10
client.tm.degradeCheckPeriod=2000
client.tm.interceptorOrder=-2147482648
client.undo.dataValidation=true
client.undo.logSerialization=jackson
client.undo.onlyCareUpdateColumns=true
server.undo.logSaveDays=7
server.undo.logDeletePeriod=86400000
client.undo.logTable=undo_log
client.undo.compress.enable=true
client.undo.compress.type=zip
client.undo.compress.threshold=64k
#For TCC transaction mode
tcc.fence.logTableName=tcc_fence_log
tcc.fence.cleanPeriod=1h
#Log rule configuration, for client and server
log.exceptionRate=100
#Transaction storage configuration, only for the server. The file, DB, and redis configuration values are optional.
#store.mode=file
#store.lock.mode=file
#store.session.mode=file
#Used for password encryption
#store.publicKey=
#If `store.mode,store.lock.mode,store.session.mode` are not equal to `file`, you can remove the configuration block.
#store.file.dir=file_store/data
#store.file.maxBranchSessionSize=16384
#store.file.maxGlobalSessionSize=512
#store.file.fileWriteBufferCacheSize=16384
#store.file.flushDiskMode=async
#store.file.sessionReloadReadSize=100
#These configurations are required if the `store mode` is `db`. If `store.mode,store.lock.mode,store.session.mode` are not equal to `db`, you can remove the configuration block.
store.db.datasource=druid
store.db.dbType=mysql
store.db.driverClassName=com.mysql.jdbc.Driver
store.db.url=jdbc:mysql://10.211.55.5:3306/seata?useUnicode=true&rewriteBatchedStatements=true
store.db.user=root
store.db.password=123456
store.db.minConn=5
store.db.maxConn=30
store.db.globalTable=global_table
store.db.branchTable=branch_table
store.db.distributedLockTable=distributed_lock
store.db.queryLimit=100
store.db.lockTable=lock_table
store.db.maxWait=5000
#These configurations are required if the `store mode` is `redis`. If `store.mode,store.lock.mode,store.session.mode` are not equal to `redis`, you can remove the configuration block.
#store.redis.mode=single
#store.redis.single.host=127.0.0.1
#store.redis.single.port=6379
#store.redis.sentinel.masterName=
#store.redis.sentinel.sentinelHosts=
#store.redis.maxConn=10
#store.redis.minConn=1
#store.redis.maxTotal=100
#store.redis.database=0
#store.redis.password=
#store.redis.queryLimit=100
#Transaction rule configuration, only for the server
server.recovery.committingRetryPeriod=1000
server.recovery.asynCommittingRetryPeriod=1000
server.recovery.rollbackingRetryPeriod=1000
server.recovery.timeoutRetryPeriod=1000
server.maxCommitRetryTimeout=-1
server.maxRollbackRetryTimeout=-1
server.rollbackRetryTimeoutUnlockEnable=false
server.distributedLockExpireTime=10000
server.xaerNotaRetryTimeout=60000
server.session.branchAsyncQueueSize=5000
server.session.enableBranchAsyncRemove=false
server.enableParallelRequestHandle=false
#Metrics configuration, only for the server
metrics.enabled=false
metrics.registryType=compact
metrics.exporterList=prometheus
metrics.exporterPrometheusPort=9898进入 /usr/local/project/seata/script/config-center/nacos
执行 sh nacos-config.sh
登录自己的nocas地址
新建数据库表 seata
执行脚本(脚本位置：seata/script/server/db/mysql.sql)
代码语言：javascript复制-- -------------------------------- The script used when storeMode is 'db' --------------------------------
-- the table to store GlobalSession data
CREATE TABLE IF NOT EXISTS `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_status_gmt_modified` (`status` , `gmt_modified`),
KEY `idx_transaction_id` (`transaction_id`)
) ENGINE = InnoDB
DEFAULT CHARSET = utf8mb4;
-- the table to store BranchSession data
CREATE TABLE IF NOT EXISTS `branch_table`
(
`branch_id` BIGINT NOT NULL,
`xid` VARCHAR(128) NOT NULL,
`transaction_id` BIGINT,
`resource_group_id` VARCHAR(32),
`resource_id` VARCHAR(256),
`branch_type` VARCHAR(8),
`status` TINYINT,
`client_id` VARCHAR(64),
`application_data` VARCHAR(2000),
`gmt_create` DATETIME(6),
`gmt_modified` DATETIME(6),
PRIMARY KEY (`branch_id`),
KEY `idx_xid` (`xid`)
) ENGINE = InnoDB
DEFAULT CHARSET = utf8mb4;
-- the table to store lock data
CREATE TABLE IF NOT EXISTS `lock_table`
(
`row_key` VARCHAR(128) NOT NULL,
`xid` VARCHAR(128),
`transaction_id` BIGINT,
`branch_id` BIGINT NOT NULL,
`resource_id` VARCHAR(256),
`table_name` VARCHAR(32),
`pk` VARCHAR(36),
`status` TINYINT NOT NULL DEFAULT '0' COMMENT '0:locked ,1:rollbacking',
`gmt_create` DATETIME,
`gmt_modified` DATETIME,
PRIMARY KEY (`row_key`),
KEY `idx_status` (`status`),
KEY `idx_branch_id` (`branch_id`),
KEY `idx_xid_and_branch_id` (`xid` , `branch_id`)
) ENGINE = InnoDB
DEFAULT CHARSET = utf8mb4;
CREATE TABLE IF NOT EXISTS `distributed_lock`
(
`lock_key` CHAR(20) NOT NULL,
`lock_value` VARCHAR(20) NOT NULL,
`expire` BIGINT,
primary key (`lock_key`)
) ENGINE = InnoDB
DEFAULT CHARSET = utf8mb4;
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('AsyncCommitting', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('RetryCommitting', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('RetryRollbacking', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('TxTimeoutCheck', ' ', 0);进入 /usr/local/project/seata/bin
启动 seata
./seata-server.sh
启动完成会注册到 nacos 中
至此Seata-Server安装完成，并服务注入nacos
Seata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。
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。
一言蔽之，下订单—>扣库存—>减账户(余额)。
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。
建库SQL
代码语言：javascript复制CREATE DATABASE seata_order;
CREATE DATABASE seata_storage;
CREATE DATABASE seata_account;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=1 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=1 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;- 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=1 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;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-0.9.0seataconf目录下的db_ undo_ log.sql
- 建表SQL
-- 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;Seata之Order-Module配置搭建
下订单 -> 减库存 -> 扣余额 -> 改（订单）状态
seata-order-service2001
POM
代码语言：javascript复制<?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>springcloud</artifactId>
<groupId>cn.kt</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>seata-order-service2001</artifactId>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
</properties>
<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-spring-boot-starter</artifactId>
<groupId>io.seata</groupId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>io.seata</groupId>
<artifactId>seata-spring-boot-starter</artifactId>
<version>1.5.2</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>5.1.6</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>配置文件
YML
代码语言：javascript复制server:
port: 2001
spring:
application:
name: seata-order-service
cloud:
nacos:
discovery:
server-addr: 10.211.55.5:1111
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://10.211.55.5:3306/seata_order
username: root
password: 123456
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath:mapper/*.xml
seata:
tx-service-group: my_tx_group
config:
type: nacos
nacos:
server-addr: 10.211.55.5:1111 #填线上Nacos的IP:PORT
namespace: #命名空间，使用默认的不用填
group: SEATA_GROUP #组
username: nacos
password: nacos
data-id: seataServer.properties #seataServer配置文件
registry:
type: nacos
nacos:
application: seata-server #注册服务名称
server-addr: 10.211.55.5:1111 #填线上Nacos的IP:PORT
group: SEATA_GROUP #组
namespace: #命名空间，使用默认的不用填
cluster: default
username: nacos
password: nacos
store:
mode: db
db:
datasource: druid
db-type: mysql
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://10.211.55.5:3306/seata?serverTimezone=Asia/Shanghai #填线上Mysql的IP:PORT，seata数据库名，要和前面插入seata表同一个名
user: root #数据库账号
password: 123456 #数据库密码
min-conn: 5
max-conn: 100
global-table: global_table
branch-table: branch_table
lock-table: lock_table
distributed-lock-table: distributed_lock
query-limit: 100
max-wait: 5000
service:
vgroup-mapping:
my_tx_group: my_tx_group
grouplist:
default: 10.211.55.5:8091特别要注意配置问题
domain
代码语言：javascript复制package cn.kt.springcloud.domain;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
/**
* Created by tao.
* Date: 2022/9/4 10:45
* 描述:
*/
@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 cn.kt.springcloud.domain;
import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.math.BigDecimal;
/**
* Created by tao.
* Date: 2022/9/4 10:45
* 描述:
*/
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Order {
private Long id;
private Long userId;
private Long productId;
private Integer count;
@JsonFormat(shape = JsonFormat.Shape.STRING)
private BigDecimal money;
private Integer status; //订单状态：0：创建中；1：已完结
}Seata之Order-Module撸码(上)
Dao接口及实现
代码语言：javascript复制package cn.kt.springcloud.dao;
import cn.kt.springcloud.domain.Order;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
/**
* Created by tao.
* Date: 2022/9/4 10:46
* 描述:
*/
@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="cn.kt.springcloud.dao.OrderDao">
<resultMap id="BaseResultMap" type="cn.kt.springcloud.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>Service接口及实现
- OrderService
- OrderServiceImpl
- StorageService
- AccountService
package cn.kt.springcloud.service;
import cn.kt.springcloud.domain.Order;
/**
* Created by tao.
* Date: 2022/9/4 10:55
* 描述:
*/
public interface OrderService {
void create(Order order);
}package cn.kt.springcloud.service;
import cn.kt.springcloud.domain.CommonResult;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
/**
* Created by tao.
* Date: 2022/9/4 11:02
* 描述:
*/
import java.math.BigDecimal;
@FeignClient(value = "seata-storage-service")
public interface StorageService {
@PostMapping(value = "/storage/decrease")
CommonResult decrease(@RequestParam("productId") Long productId, @RequestParam("count") Integer count);
}package cn.kt.springcloud.service;
import cn.kt.springcloud.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;
/**
* Created by tao.
* Date: 2022/9/4 11:01
* 描述:
*/
@FeignClient(value = "seata-account-service")
public interface AccountService {
@PostMapping(value = "/account/decrease")
CommonResult decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money);
}package cn.kt.springcloud.service.impl;
import cn.kt.springcloud.dao.OrderDao;
import cn.kt.springcloud.domain.Order;
import cn.kt.springcloud.service.AccountService;
import cn.kt.springcloud.service.OrderService;
import cn.kt.springcloud.service.StorageService;
import io.seata.spring.annotation.GlobalTransactional;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
/**
* Created by tao.
* Date: 2022/9/4 11:00
* 描述:
*/
@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->扣库存->减余额->改状态
*/
@Override
//@GlobalTransactional(name = "my_tx_group",rollbackFor = Exception.class)
public void create(Order order) {
log.info("----->开始新建订单");
//1 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1,1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，O(∩_∩)O哈哈~");
}
}Seata之Order-Module撸码(下)
Controller
代码语言：javascript复制package cn.kt.springcloud.controller;
import cn.kt.springcloud.domain.CommonResult;
import cn.kt.springcloud.domain.Order;
import cn.kt.springcloud.service.OrderService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/**
* Created by tao.
* Date: 2022/9/4 11:21
* 描述:
*/
@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
- DataSourceProxyConfig
package cn.kt.springcloud.config;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Configuration;
/**
* Created by tao.
* Date: 2022/9/4 11:24
* 描述:
*/
@Configuration
@MapperScan({"cn.kt.springcloud.dao"})
public class MyBatisConfig {
}package cn.kt.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.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import javax.sql.DataSource;
/**
* Created by tao.
* Date: 2022/9/4 11:24
* 描述: 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 DruidDataSource druidDataSource() {
return new DruidDataSource();
}
@Primary
@Bean
public DataSourceProxy dataSource(DruidDataSource druidDataSource) {
return new DataSourceProxy(druidDataSource);
}
}主启动
代码语言：javascript复制package cn.kt.springcloud;
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;
import org.springframework.context.annotation.ComponentScan;
/**
* Created by tao.
* Date: 2022/9/4 11:25
* 描述:
*/
@EnableDiscoveryClient
@EnableFeignClients
//取消数据源的自动创建，而是使用自己定义的
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
public class SeataOrderMainApp2001 {
public static void main(String[] args) {
SpringApplication.run(SeataOrderMainApp2001.class, args);
}
}Seata之Storage-Module说明
与seata-order-service2001模块大致相同
seata-storage-service2002
POM（与seata-order-service2001模块大致相同）
YML
代码语言：javascript复制server:
port: 2002
spring:
application:
name: seata-storage-service
cloud:
nacos:
discovery:
server-addr: 10.211.55.5:1111
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://10.211.55.5:3306/seata_storage
username: root
password: 123456
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath:mapper/*.xml
seata:
tx-service-group: my_tx_group
config:
type: nacos
nacos:
server-addr: 10.211.55.5:1111 #填线上Nacos的IP:PORT
namespace: #命名空间，使用默认的不用填
group: SEATA_GROUP #组
username: nacos
password: nacos
data-id: seataServer.properties #seataServer配置文件
registry:
type: nacos
nacos:
application: seata-server #注册服务名称
server-addr: 10.211.55.5:1111 #填线上Nacos的IP:PORT
group: SEATA_GROUP #组
namespace: #命名空间，使用默认的不用填
cluster: default
username: nacos
password: nacos
store:
mode: db
db:
datasource: druid
db-type: mysql
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://10.211.55.5:3306/seata?serverTimezone=Asia/Shanghai #填线上Mysql的IP:PORT，seata数据库名，要和前面插入seata表同一个名
user: root #数据库账号
password: 123456 #数据库密码
min-conn: 5
max-conn: 100
global-table: global_table
branch-table: branch_table
lock-table: lock_table
distributed-lock-table: distributed_lock
query-limit: 100
max-wait: 5000
service:
vgroup-mapping:
my_tx_group: my_tx_group
grouplist:
default: 10.211.55.5:8091domain
代码语言：javascript复制package cn.kt.springcloud.domain;
import lombok.Data;
/**
* Created by tao.
* Date: 2022/9/17 16:21
* 描述:
*/
@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;
}CommonResult（与seata-order-service2001模块大致相同）
Dao接口及实现
代码语言：javascript复制package cn.kt.springcloud.dao;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
/**
* Created by tao.
* Date: 2022/9/17 16:23
* 描述:
*/
@Mapper
public interface StorageDao {
//扣减库存
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="cn.kt.springcloud.dao.StorageDao">
<resultMap id="BaseResultMap" type="cn.kt.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>
<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
代码语言：javascript复制package cn.kt.springcloud.service;
/**
* Created by tao.
* Date: 2022/9/17 16:26
* 描述:
*/
public interface StorageService {
/**
* 扣减库存
*/
void decrease(Long productId, Integer count);
}package cn.kt.springcloud.service.impl;
import cn.kt.springcloud.dao.StorageDao;
import cn.kt.springcloud.service.StorageService ;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
/**
* Created by tao.
* Date: 2022/9/17 16:27
* 描述:
*/
@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");
}
}Controller
代码语言：javascript复制package cn.kt.springcloud.controller;
import cn.kt.springcloud.domain.CommonResult;
import cn.kt.springcloud.service.StorageService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* Created by tao.
* Date: 2022/9/17 16:28
* 描述:
*/
@RestController
public class StorageController {
@Autowired
private StorageService storageService;
/**
* 扣减库存
*/
@PostMapping("/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（与seata-order-service2001模块大致相同）
主启动
代码语言：javascript复制package cn.kt.springcloud;
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;
import org.springframework.context.annotation.ComponentScan;
/**
* Created by tao.
* Date: 2022/9/4 11:25
* 描述:
*/
@EnableDiscoveryClient
@EnableFeignClients
//取消数据源的自动创建，而是使用自己定义的
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
public class SeataStorageMainApp2002 {
public static void main(String[] args) {
SpringApplication.run(SeataStorageMainApp2002.class, args);
}
}Seata之Account-Module说明
与seata-order-service2001模块大致相同
seata-account-service2003
POM（与seata-order-service2001模块大致相同）
YML
代码语言：javascript复制server:
port: 2003
spring:
application:
name: seata-account-service
cloud:
nacos:
discovery:
server-addr: 10.211.55.5:1111
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://10.211.55.5:3306/seata_account
username: root
password: 123456
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath:mapper/*.xml
seata:
tx-service-group: my_tx_group
config:
type: nacos
nacos:
server-addr: 10.211.55.5:1111 #填线上Nacos的IP:PORT
namespace: #命名空间，使用默认的不用填
group: SEATA_GROUP #组
username: nacos
password: nacos
data-id: seataServer.properties #seataServer配置文件
registry:
type: nacos
nacos:
application: seata-server #注册服务名称
server-addr: 10.211.55.5:1111 #填线上Nacos的IP:PORT
group: SEATA_GROUP #组
namespace: #命名空间，使用默认的不用填
cluster: default
username: nacos
password: nacos
store:
mode: db
db:
datasource: druid
db-type: mysql
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://10.211.55.5:3306/seata?serverTimezone=Asia/Shanghai #填线上Mysql的IP:PORT，seata数据库名，要和前面插入seata表同一个名
user: root #数据库账号
password: 123456 #数据库密码
min-conn: 5
max-conn: 100
global-table: global_table
branch-table: branch_table
lock-table: lock_table
distributed-lock-table: distributed_lock
query-limit: 100
max-wait: 5000
service:
vgroup-mapping:
my_tx_group: my_tx_group
grouplist:
default: 10.211.55.5:8091domain
代码语言：javascript复制package cn.kt.springcloud.domain;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.math.BigDecimal;
/**
* Created by tao.
* Date: 2022/9/17 16:36
* 描述:
*/
@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;
}CommonResult（与seata-order-service2001模块大致相同）
Dao接口及实现
代码语言：javascript复制package cn.kt.springcloud.dao;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.math.BigDecimal;
/**
* Created by tao.
* Date: 2022/9/17 16:41
* 描述:
*/
@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="cn.kt.springcloud.dao.AccountDao">
<resultMap id="BaseResultMap" type="cn.kt.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
代码语言：javascript复制package cn.kt.springcloud.service;
import org.springframework.web.bind.annotation.RequestParam;
import java.math.BigDecimal;
/**
* Created by tao.
* Date: 2022/9/17 16:44
* 描述:
*/
public interface AccountService {
/**
* 扣减账户余额
*
* @param userId 用户id
* @param money 金额
*/
void decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money);
}package cn.kt.springcloud.service.impl;
import cn.kt.springcloud.dao.AccountDao;
import cn.kt.springcloud.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;
/**
* Created by tao.
* Date: 2022/9/17 16:45
* 描述:
*/
@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");
//模拟超时异常，全局事务回滚
//暂停几秒钟线程
/*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
代码语言：javascript复制package cn.kt.springcloud.controller;
import cn.kt.springcloud.domain.CommonResult;
import cn.kt.springcloud.service.AccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
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;
/**
* Created by tao.
* Date: 2022/9/17 16:46
* 描述:
*/
@RestController
public class AccountController {
@Resource
AccountService accountService;
/**
* 扣减账户余额
*/
@PostMapping("/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（与seata-order-service2001模块大致相同）
主启动
代码语言：javascript复制package cn.kt.springcloud;
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;
import org.springframework.context.annotation.ComponentScan;
/**
* Created by tao.
* Date: 2022/9/4 11:25
* 描述:
*/
@EnableDiscoveryClient
@EnableFeignClients
//取消数据源的自动创建，而是使用自己定义的
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
public class SeataAccountMainApp2003 {
public static void main(String[] args) {
SpringApplication.run(SeataAccountMainApp2003.class, args);
}
}Seata之@GlobalTransactional验证
下订单 -> 减库存 -> 扣余额 -> 改（订单）状态
数据库初始情况：
正常下单 -http://localhost:2001/order/create?userId=1&productId=1&count=10&money=100
运行后台：
数据库正常下单后状况：
超时异常，没加@GlobalTransactional
模拟AccountServiceImpl添加超时
代码语言：javascript复制package cn.kt.springcloud.service.impl;
import cn.kt.springcloud.dao.AccountDao;
import cn.kt.springcloud.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;
/**
* Created by tao.
* Date: 2022/9/17 16:45
* 描述:
*/
@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");
//模拟超时异常，全局事务回滚
//暂停几秒钟线程
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");
}
}另外，OpenFeign的调用默认时间是1s以内，所以最后会抛异常。
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
超时异常，加了@GlobalTransactional
用@GlobalTransactional标注OrderServiceImpl的create()方法。
代码语言：javascript复制@Service
@Slf4j
public class OrderServiceImpl implements OrderService {
...
/**
* 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->扣库存->减余额->改状态
*/
@Override
//rollbackFor = Exception.class表示对任意异常都进行回滚
@GlobalTransactional(name = "my_tx_group",rollbackFor = Exception.class)
public void create(Order order)
{
...
}
}还是模拟AccountServiceImpl添加超时，下单后数据库数据并没有任何改变，记录都添加不进来，达到出异常，数据库回滚的效果。
Seata之原理简介
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，用1.0以后的版本。Alina Gingertail
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
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，非常快速地完成。
- 回滚通过一阶段的回滚日志进行反向补偿。
link
- 一阶段加载
在一阶段，Seata会拦截“业务SQL”
- 解析SQL语义，找到“业务SQL" 要更新的业务数据，在业务数据被更新前，将其保存成"before image”
- 执行“业务SQL" 更新业务数据，在业务数据更新之后,
- 其保存成"after image”，最后生成行锁。
以上操作全部在一个数据库事务内完成, 这样保证了一阶段操作的原子性。
- 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。
- 二阶段回滚
二阶段如果是回滚的话，Seata 就需要回滚一阶段已经执行的 “业务SQL"，还原业务数据。
回滚方式便是用"before image"还原业务数据；但在还原前要首先要校验脏写，对比“数据库当前业务数据”和"after image"。
如果两份数据完全一致就说明没有脏写， 可以还原业务数据，如果不一致就说明有脏写, 出现脏写就需要转人工处理。
补充
学习源码
https://gitee.com/KT1205529635/springcloud/tree/master/code/springcloud
