Springcloud Alibaba Seata处理分布式事务的使用小结

﹏ヽ暗。殇╰゛Y 2022-10-29 15:20 135阅读 0赞

**目录**

1. Seata概述

1.1 Seata简介

1.2 Seata安装配置

2. 订单/库存/账户业务案例

2.1 数据库准备

2.2 微服务准备

2.2.1 订单模块seata-order-service2001

2.2.2 库存模块seata-storage-service2002

2.2.3 账户模块seata-account-service2003

2.3 案例测试

--------------------

# 1. Seata概述 #

> 众所周知，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][] 是一款开源的分布式事务解决方案，致力于提供高性能和简单易用的分布式事务服务。Seata 将为用户提供了 **AT、TCC、SAGA 和 XA** 事务模式，为用户打造一站式的分布式解决方案。

## 1.1 Seata简介 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70][]

1) 分布式事务处理过程的ID（全局唯一的事务ID）+三组件模型。

*  TC - 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 - 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 - 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。

2) 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。

## 1.2 Seata安装配置 ##

1) 下载[Seata][Seata 1]的[seata-server-1.3.0.zip][]。

2) 先备份原始file.conf文件，然后修改file.conf。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 1][]

3) 先备份原始registry.conf文件，然后修改registry.conf。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 2][]

4) 数据库新建库seata，然后创建表。

-- 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`)
    );

5) 先启动Nacos再启动Seata（.\\seata\\bin\\seata-server.bat）。

# 2. 订单/库存/账户业务案例 #

以下创建三个服务：订单、库存、账户。

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的余额，最后订单服务中修改订单状态为已完成。

## 2.1 数据库准备 ##

1) 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。

CREATE DATABASE seata_order;
    CREATE DATABASE seata_storage;
    CREATE DATABASE seata_account;

2) 对应的3库分别建对业务表。

*  seata\_order库：创建t\_order表。
 *  seata\_storage库：创建t\_storage表。
 *  seata\_account库：创建t\_account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` BIGINT(11) DEFAULT NULL COMMENT '数量',
        `money` BIGINT(11) DEFAULT NULL COMMENT '金额',
        `status` BIGINT(11) DEFAULT NULL COMMENT '订单状态: 0创建中 1已完结'
    ) ENGINE = INNODB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;
    
    CREATE TABLE t_storage(
        `id` BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
        `product_id` BIGINT(11) DEFAULT NULL COMMENT '产品id',
        `total` BIGINT(11) DEFAULT NULL COMMENT '总库存',
        `used` BIGINT(11) DEFAULT NULL COMMENT '已用库存',
        `residue` BIGINT(11) DEFAULT NULL COMMENT '剩余库存'
    ) ENGINE = INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8; 
    INSERT INTO t_storage( `id`,`product_id`, `total`,`used`,`residue`) values(1,1,100,0,100);
    
    CREATE TABLE t_account(
        `id` BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
        `user_id` BIGINT(11) DEFAULT NULL COMMENT '用户id',
        `total` BIGINT(11) DEFAULT NULL COMMENT '总额度',
        `used` BIGINT(11) DEFAULT NULL COMMENT '已用额度',
        `residue` BIGINT(11) DEFAULT NULL COMMENT '剩余额度'
    ) ENGINE = INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8; 
    INSERT INTO t_account( `id`,`user_id`, `total`,`used`,`residue`) values(1,1,1000,0,1000);

3) 订单-库存-账户3个库下都需要创建各自的回滚日志表。

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;

4) 当前数据库的表。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 3][]

## 2.2 微服务准备 ##

假设业务需求：下订单 -> 减库存->扣余额 ->改（订单）状态。

以下案例代码的[Github地址][Github]。

相关modules是：seata-order-service2001, seata-storage-service2002, seata-account-service2003。

### 2.2.1 订单模块seata-order-service2001 ###

1) 添加Seata依赖。

<dependency>
    	<groupId>com.alibaba.cloud</groupId>
    	<artifactId>spring-cloud-starter-alibaba-seata</artifactId>
    	<exclusions>
    		<exclusion>
    			<groupId>io.seata</groupId>
    			<artifactId>seata-all</artifactId>
    		</exclusion>
    	</exclusions>
    </dependency>
    <dependency>
    	<groupId>io.seata</groupId>
    	<artifactId>seata-all</artifactId>
    	<version>1.1.0</version>
    </dependency>

2) 配置Seata。

server:
      port: 2001
    
    spring:
      application:
        name: seata-order-service
      cloud:
        alibaba:
          seata:
            # 自定义事务组名称需要与seata-server中的对应
            tx-service-group: fsp_tx_group
        nacos:
          discovery:
            server-addr: 127.0.0.1:8848
      datasource:
        # 当前数据源操作类型
        type: com.alibaba.druid.pool.DruidDataSource
        # mysql驱动类
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://localhost:3306/seata_order?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
        username: root
        password: 123456
    feign:
      hystrix:
        enabled: false
    logging:
      level:
        io:
          seata: info
    
    mybatis:
      mapperLocations: classpath*:mapper/*.xml

3) 添加resources/file.conf。

transport {
      # tcp udt unix-domain-socket
      type = "TCP"
      #NIO NATIVE
      server = "NIO"
      #enable heartbeat
      heartbeat = true
      #thread factory for netty
      thread-factory {
        boss-thread-prefix = "NettyBoss"
        worker-thread-prefix = "NettyServerNIOWorker"
        server-executor-thread-prefix = "NettyServerBizHandler"
        share-boss-worker = false
        client-selector-thread-prefix = "NettyClientSelector"
        client-selector-thread-size = 1
        client-worker-thread-prefix = "NettyClientWorkerThread"
        # netty boss thread size,will not be used for UDT
        boss-thread-size = 1
        #auto default pin or 8
        worker-thread-size = 8
      }
      shutdown {
        # when destroy server, wait seconds
        wait = 3
      }
      serialization = "seata"
      compressor = "none"
    }
    service {
      #vgroup->rgroup
      # 事务组名称   但要注意：版本不同的Seata，这个vgroupMapping配置名可能不一样导致不能注册到Seata
      vgroupMapping.fsp_tx_group = "default"
      #only support single node
      default.grouplist = "127.0.0.1:8091"
      #degrade current not support
      enableDegrade = false
      #disable
      disable = false
      #unit ms,s,m,h,d represents milliseconds, seconds, minutes, hours, days, default permanent
      max.commit.retry.timeout = "-1"
      max.rollback.retry.timeout = "-1"
    }
    
    client {
      async.commit.buffer.limit = 10000
      lock {
        retry.internal = 10
        retry.times = 30
      }
      report.retry.count = 5
      tm.commit.retry.count = 1
      tm.rollback.retry.count = 1
    }
    
    ## transaction log store
    store {
      ## store mode: file、db
      #mode = "file"
      mode = "db"
    
      ## file store
      file {
        dir = "sessionStore"
    
        # branch session size , if exceeded first try compress lockkey, still exceeded throws exceptions
        max-branch-session-size = 16384
        # globe session size , if exceeded throws exceptions
        max-global-session-size = 512
        # file buffer size , if exceeded allocate new buffer
        file-write-buffer-cache-size = 16384
        # when recover batch read size
        session.reload.read_size = 100
        # async, sync
        flush-disk-mode = async
      }
    
      ## database store
      db {
        ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp) etc.
        datasource = "dbcp"
        ## mysql/oracle/h2/oceanbase etc.
        db-type = "mysql"
        driver-class-name = "com.mysql.jdbc.Driver"
        url = "jdbc:mysql://127.0.0.1:3306/seata"
        user = "root"
        password = "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
      }
    }

4) 添加resources/registry.conf。

registry {
      # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
      type = "nacos"
    
      nacos {
        #serverAddr = "localhost"
        serverAddr = "localhost:8848"
        namespace = ""
        cluster = "default"
      }
      eureka {
        serviceUrl = "http://localhost:8761/eureka"
        application = "default"
        weight = "1"
      }
      redis {
        serverAddr = "localhost:6379"
        db = "0"
      }
      zk {
        cluster = "default"
        serverAddr = "127.0.0.1:2181"
        session.timeout = 6000
        connect.timeout = 2000
      }
      consul {
        cluster = "default"
        serverAddr = "127.0.0.1:8500"
      }
      etcd3 {
        cluster = "default"
        serverAddr = "http://localhost:2379"
      }
      sofa {
        serverAddr = "127.0.0.1:9603"
        application = "default"
        region = "DEFAULT_ZONE"
        datacenter = "DefaultDataCenter"
        cluster = "default"
        group = "SEATA_GROUP"
        addressWaitTime = "3000"
      }
      file {
        name = "file.conf"
      }
    }
    
    config {
      # file、nacos 、apollo、zk、consul、etcd3
      type = "file"
    
      nacos {
        serverAddr = "localhost"
        namespace = ""
      }
      consul {
        serverAddr = "127.0.0.1:8500"
      }
      apollo {
        app.id = "seata-server"
        apollo.meta = "http://192.168.1.204:8801"
      }
      zk {
        serverAddr = "127.0.0.1:2181"
        session.timeout = 6000
        connect.timeout = 2000
      }
      etcd3 {
        serverAddr = "http://localhost:2379"
      }
      file {
        name = "file.conf"
      }
    }

5) 添加Feign Service接口。

@FeignClient(value = "seata-storage-service")
    public interface StorageService {
    
        /**
         * 减库存
         * @param productId
         * @param count
         * @return
         */
        @PostMapping(value = "/storage/decrease")
        CommonResult decrease(@RequestParam("productId") Long productId, @RequestParam("count") Integer count);
    }
    
    @FeignClient(value = "seata-account-service")
    public interface AccountService {
    
        /**
         * 减余额
         * @param userId
         * @param money
         * @return
         */
        @PostMapping(value = "/account/decrease")
        CommonResult decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money);
    }

6) 添加订单服务 Service接口。

/**
     * 创建订单->调用库存服务扣减库存->调用账户服务扣减账户余额->修改订单状态
     * 简单说:
     * 下订单->减库存->减余额->改状态
     * GlobalTransactional seata开启分布式事务,异常时回滚,name保证唯一即可
     * @param order 订单对象
     */
    @Override
    ///@GlobalTransactional(name = "fsp-create-order", rollbackFor = Exception.class)
    public void create(Order order) {
    	// 1 新建订单
    	log.info("----->开始新建订单");
    	orderDao.create(order);
    
    	// 2 扣减库存
    	log.info("----->订单微服务开始调用库存,做扣减Count");
    	storageService.decrease(order.getProductId(), order.getCount());
    	log.info("----->订单微服务开始调用库存,做扣减End");
    
    	// 3 扣减账户
    	log.info("----->订单微服务开始调用账户,做扣减Money");
    	accountService.decrease(order.getUserId(), order.getMoney());
    	log.info("----->订单微服务开始调用账户,做扣减End");
    
    	// 4 修改订单状态,从0到1,1代表已完成
    	log.info("----->修改订单状态开始");
    	orderDao.update(order.getUserId(), 0);
    
    	log.info("----->下订单结束了,O(∩_∩)O哈哈~");
    }

### 2.2.2 库存模块seata-storage-service2002 ###

除了dao层和mapper有点区别，其他配置基本和seata-order-service2001的一样。

1) 添加库存服务 Service接口。

@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");
    }

2) 添加Storage domain。

@Data
    @AllArgsConstructor
    @NoArgsConstructor
    public class Storage {
    
        private Long id;
    
        private Integer total;
    
        private Integer used;
    
        private Integer  residue;
    }

### 2.2.3 账户模块seata-account-service2003 ###

1) 添加账户服务 Service接口。

@Override
    public void decrease(Long userId, BigDecimal money) {
    	LOGGER.info("----> account-service中扣减用户余额开始");
    	accountDao.decrease(userId,money);
    	LOGGER.info("----> account-service中扣减用户余额开始");
    }

2) 天剑Account domain。

@Data
    @AllArgsConstructor
    @NoArgsConstructor
    public class Account {
    
        private Long id;
    
        private Long userId;
    
        private BigDecimal total;
    
        private BigDecimal used;
    
        private BigDecimal  residue;
    }

## 2.3 案例测试 ##

1) 数据库初始状态。

![202102152330308.png][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 4][]

![20210215233056854.png][]

2) 先启动Nacos server，然后启动Seata server，再启动上面三个module。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 5][]

3) 访问接口（localhost:2001/order/create?userId=1&productId=1&count=10&money=100）。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 6][]

4) 由于扣减账户余额的service设置了sleep 10s，所以导致超时异常。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 7][]

5) 因为OrderService设置了GlobalTransactional，有异常的时候，全部事物Rollback，所以表数据都没有改变。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 8][]

[Seata]: http://seata.io/zh-cn/docs/overview/what-is-seata.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70]: /images/20221024/dcd781a38ebe47459e9dadd6437c3915.png
[Seata 1]: https://github.com/seata/seata/releases
[seata-server-1.3.0.zip]: https://github.com/seata/seata/releases/download/v1.3.0/seata-server-1.3.0.zip
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 1]: /images/20221024/594ea63938be4e70b13584f45a9b8359.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 2]: /images/20221024/e493d927dc204273866257584363f7cd.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBU3RyaXZlcg_size_16_color_FFFFFF_t_70 3]: /images/20221024/027a5782217b43118489d0a1f120cfa2.png
[Github]: https://github.com/BAStriver/springcloud-test
[202102152330308.png]: /images/20221024/2fe82ea58d524eeb8c396dab093b4199.png
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