分布式事务问题由来
分布式前
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:
处理过程:
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
个人理解,不见得对
https://github.com/seata/seata/releases
本地@Transactional
全局@GlobalTransactional
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
http://seata.io/zh-cn/
0.9.0
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
下载完成后解压
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 } }
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`) );
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
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
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;
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;
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;
-- 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;
下订单 -> 减库存 -> 扣余额 -> 改(订单)状态
seata-order-service2001
<?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>
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
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 } }
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" } }
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 }
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>
package com.dance.springcloud.service; import com.dance.springcloud.domain.Order; public interface OrderService { void create(Order order); }
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~"); } }
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); }
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); }
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"); } }
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 { }
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(); } }
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-storage-service2002
<?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>
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
直接从2001拷贝到,2002
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
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>
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"); } }
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!"); } }
从2001拷贝到2002
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-order-service2003
<?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>
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
从2002拷贝到2003
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
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>
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"); } }
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!"); } }
从2002拷贝到2003
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); } }
下订单 -> 减库存 -> 扣余额 -> 改(订单)状态
select * from t_order
select * from t_storage
select * from t_account
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
正常下单 - http://localhost:2001/order/create?userId=1&productId=1&count=10&money=100
ok调用成功
select * from t_order
一条订单数量10,金额100,已支付 ok
select * from t_storage
总数100,已出库10,剩余90 ok
select * from t_account
总金额1000 使用100 剩余900 ok
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。
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
select * from t_order
2号订单支付失败
select * from t_storage
总数100,已出库20,剩余80 ok
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
用@GlobalTransactional标注OrderServiceImpl的create()方法。 2001工程
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。
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
在一阶段,Seata会拦截“业务SQL”
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