20-Spring Cloud Alibaba Seata
2021/11/15 6:09:55
本文主要是介绍20-Spring Cloud Alibaba Seata，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！
简介
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 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是什么
官方网址
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。
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。
自己理解:感觉应该是刚性分布式事务(XA理论)的二段提交思想,由TC统筹全局,TM管理分支,RM反馈单一DB的情况
- 开始由TM定义事务的边界,并向TC申请开始一个全局事务,生成一个唯一ID
- RM通过取到这个唯一ID,向TM申请注册一个分支事务,也就是全局事务中的其中一条
- RM上报自己分支事务的情况,然后由TM记录,并根据记录决定是否这个全局事务是提交还是回滚
- TC根据唯一ID获取全部的分支事务,决定是全部提交,还是全部回滚
个人理解,不见得对
Seata-Server安装
下载
https://github.com/seata/seata/releases
使用
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,就可以解决分布式事务问题
安装
官网
http://seata.io/zh-cn/
下载版本
0.9.0
安装步骤
下载(不想找的直接粘贴这个地址去下载):https://github.com/seata/seata/releases/download/v0.9.0/seata-server-0.9.0.zip
解压
下载完成后解压
修改file.conf
修改之前先备份
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
修改Service模块
service {
#vgroup->rgroup
# 注释默认的
# vgroup_mapping.my_test_tx_group = "default"
vgroup_mapping.my_test_tx_group = "fsp_tx_group"
#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"
}
修改store模块
## transaction log store
store {
## store mode: file、db
# mode = "file"
# 修改为数据库 默认为文件
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 = "123456"
min-conn = 1
max-conn = 3
global.table = "global_table"
branch.table = "branch_table"
lock-table = "lock_table"
query-limit = 100
}
}
新建数据库
在mysql 中新建 seata 数据库
在数据库中新建表
建表语句在配置文件db_store.sql中
-- 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`) );
修改registry.conf
同样的修改之前先备份
registry {
# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
#type = "file"
# 修改为Nacos注册
type = "nacos"
nacos {
# serverAddr = "localhost"
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
先启动Nacos端口号8848 nacos\bin\startup.cmd
再启动seata-server - seata-server-0.9.0\seata\bin\seata-server.bat
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。
创建三个数据库
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;
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
-- 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
新建2001项目
seata-order-service2001
修改POM.xml
<?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>com.dance.springcloud</artifactId>
<groupId>com.dance</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-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>
新建YML配置
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: 123456
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath:mapper/*.xml
新增file.conf
在resource下新建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 = "fsp_tx_group" #修改自定义事务组名称
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://127.0.0.1:3306/seata"
user = "root"
password = "123456"
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
}
}
新增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"
}
}
新建实体类
CommonResult
package com.dance.springcloud.domain;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class CommonResult
{
private Integer code;
private String message;
private T data;
public CommonResult(Integer code, String message)
{
this(code,message,null);
}
}
Order
package com.dance.springcloud.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
}
新建DAO及其XML
OrderDao
package com.dance.springcloud.dao;
import com.dance.springcloud.domain.Order;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
@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);
}
新建xml
在resource下新建mapper文件夹,并在文件夹下创建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.dance.springcloud.dao.OrderDao">
<resultMap id="BaseResultMap" type="com.dance.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>
新建Service接口及实现
- OrderService
package com.dance.springcloud.service;
import com.dance.springcloud.domain.Order;
public interface OrderService
{
void create(Order order);
}
- OrderServiceImpl
package com.dance.springcloud.service.impl;
import com.dance.springcloud.dao.OrderDao;
import com.dance.springcloud.domain.Order;
import com.dance.springcloud.service.AccountService;
import com.dance.springcloud.service.OrderService;
import com.dance.springcloud.service.StorageService;
import io.seata.spring.annotation.GlobalTransactional;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
@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 = "fsp-create-order",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~");
}
}
- StorageService
package com.dance.springcloud.service;
import com.dance.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;
@FeignClient(value = "seata-storage-service")
public interface StorageService
{
@PostMapping(value = "/storage/decrease")
CommonResult decrease(@RequestParam("productId") Long productId, @RequestParam("count") Integer count);
}
- AccountService
package com.dance.springcloud.service;
import com.dance.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;
@FeignClient(value = "seata-account-service")
public interface AccountService
{
@PostMapping(value = "/account/decrease")
CommonResult decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money);
}
新建Controller
package com.dance.springcloud.controller;
import com.dance.springcloud.domain.CommonResult;
import com.dance.springcloud.domain.Order;
import com.dance.springcloud.service.OrderService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
@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");
}
}
新建Config
- MyBatisConfig
package com.dance.springcloud.config;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Configuration;
@Configuration
@MapperScan({"com.dance.springcloud.dao"})
public class MyBatisConfig {
}
- DataSourceProxyConfig
package com.dance.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;
/**
* 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 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();
}
}
新建主启动类
package com.dance.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;
@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配置搭建
新建2002工程
seata-storage-service2002
修改POM.xml
<?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>com.dance.springcloud</artifactId>
<groupId>com.dance</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>seata-storage-service2002</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-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>
新增YML配置
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/*.xml
新增file.conf和registry.conf
直接从2001拷贝到,2002
新增实体类
storage
package com.dance.springcloud.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;
}
CommonResult,从2001拷贝
新建DAO及其XML
StorageDao
package com.dance.springcloud.dao;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
@Mapper
public interface StorageDao {
//扣减库存
void decrease(@Param("productId") Long productId, @Param("count") Integer count);
}
StorageMapper
<?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.dance.springcloud.dao.StorageDao">
<resultMap id="BaseResultMap" type="com.dance.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>
新增Service及其实现
StorageService
package com.dance.springcloud.service;
public interface StorageService {
/**
* 扣减库存
*/
void decrease(Long productId, Integer count);
}
StorageServiceImpl
package com.dance.springcloud.service.impl;
import com.dance.springcloud.dao.StorageDao;
import com.dance.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;
@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");
}
}
新建Controller
package com.dance.springcloud.controller;
import com.dance.springcloud.domain.CommonResult;
import com.dance.springcloud.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！");
}
}
新建Config
从2001拷贝到2002
新建主启动
package com.dance.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;
@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 SeataOrderMainApp2002
{
public static void main(String[] args)
{
SpringApplication.run(SeataOrderMainApp2002.class, args);
}
}
Seata之Account-Module配置搭建
新建2003工程
seata-order-service2003
修改POM.xml
<?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>com.dance.springcloud</artifactId>
<groupId>com.dance</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>seata-order-service2003</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-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>
新增YML配置
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: 123456
feign:
hystrix:
enabled: false
logging:
level:
io:
seata: info
mybatis:
mapperLocations: classpath:mapper/*.xml
新增file.conf和registry,conf
从2002拷贝到2003
新增实体类
account
package com.dance.springcloud.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;
}
CommonResult 从2002拷贝到2003
新建DAO及其XML
package com.dance.springcloud.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
<?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.dance.springcloud.dao.AccountDao">
<resultMap id="BaseResultMap" type="com.dance.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>
新建Service及其实现类
package com.dance.springcloud.service;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import java.math.BigDecimal;
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);
}
impl
package com.dance.springcloud.service.impl;
import com.dance.springcloud.dao.AccountDao;
import com.dance.springcloud.service.AccountService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.math.BigDecimal;
import java.util.concurrent.TimeUnit;
/**
*/
@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");
accountDao.decrease(userId,money);
LOGGER.info("------->account-service中扣减账户余额结束");
}
}
新建Controller
package com.dance.springcloud.controller;
import com.dance.springcloud.domain.CommonResult;
import com.dance.springcloud.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！");
}
}
新建Config
从2002拷贝到2003
新建主启动
package com.dance.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;
@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 SeataOrderMainApp2003
{
public static void main(String[] args)
{
SpringApplication.run(SeataOrderMainApp2003.class, args);
}
}
Seata之@GlobalTransactional验证
业务
下订单 -> 减库存 -> 扣余额 -> 改（订单）状态
数据库初始情况
Seata_order库
select * from t_order
Seata_storage库
select * from t_storage
Seata_account库
select * from t_account
测试正常下单
- 启动nacos
- 启动seata
- 启动2002,2003,2001
FAQ
no available server to connect
上面的配置配置完成后启动的时候发现报错,就是这个错,在翻阅了好多文章后说的是名称对应不上,但是我对应上了之后还是报错,无奈了
全部改回去
Seata-service/conf/file.conf
改回default
重启Seata-server
修改2001 2002 2003
yml配置
改为这个,和上面的对应,之前以为是和值对应,后来翻阅了之后发现了是和
这个对应
三个项目的resource下的file.conf改为
都改回去
然后重新启动 2001 2002 2003
ok
测试
正常下单 - http://localhost:2001/order/create?userId=1&productId=1&count=10&money=100
ok调用成功
查看数据库情况
Seata_order库
select * from t_order
一条订单数量10,金额100,已支付 ok
Seata_storage库
select * from t_storage
总数100,已出库10,剩余90 ok
Seata_account库
select * from t_account
总金额1000 使用100 剩余900 ok
测试异常下单,没加@GlobalTransactional
修改代码模拟异常超时
模拟AccountServiceImpl支付超时 2003工程
OpenFeign的调用默认时间是1s以内，所以最后会抛异常。
测试
重启2003工程
正常下单 - http://localhost:2001/order/create?userId=1&productId=1&count=10&money=100
返回错误页面 ok
查看数据库情况
Seata_order库
select * from t_order
2号订单支付失败
Seata_storage库
select * from t_storage
总数100,已出库20,剩余80 ok
Seata_account库
select * from t_account
总金额1000 使用200 剩余800 异常,扣减数据库失败了
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
测试异常下单,添加@GlobalTransactional
OrderServiceImpl添加@GlobalTransactional
用@GlobalTransactional标注OrderServiceImpl的create()方法。 2001工程
测试
还是模拟AccountServiceImpl添加超时
重启2001工程
正常下单 - http://localhost:2001/order/create?userId=1&productId=1&count=10&money=100
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
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
ok,Seata使用上还是非常简单的,但是越简单的东西内部就越高度抽象,有兴趣的可以去看一下Seata的源码,完结撒花花
作者：彼岸舞
时间：2021\11\15
内容关于：Spring Cloud H版
本文属于作者原创,未经允许,禁止转发
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