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SpringCloud Alibaba Seata处理分布式事务

打印机维修培训 • 2022-12-17 • 随笔 • 阅读 15

SpringCloud Alibaba Seata处理分布式事务,第1张

SpringCloud Alibaba Seata处理分布式事务

一、Seata简介

Seata是一款开源的分布式事务解决方案，致力于在微服务架构下提供高性能和简单易用的分布式事务服务
官网地址：http://seata.io/zh-cn/
下载地址：https://github.com/seata/seata/releases

分布式事务处理过程的-ID+三组件模型：

Transaction ID XID：全局唯一的事务ID

3组件概念
Transaction Coordinator(TC) 事务协调器，维护全局事务的运行状态，负责协调并驱动全局事务的提交或回滚
Transaction Manager™ 控制全局事务的边界，负责开启一个全局事务，并最终发起全局提交或全局回滚的决议
Resource Manager(RM) 控制分支事务，负责分支注册，状态汇报，并接收事务协调器的指令，驱动分支（本地）事务的提交和回滚

事务用法Spring本地：
Spring 本地@Transactional
全局@GlobalTransactional

SEATA的分布式交易解决方案：

二、Seata-Server安装

官网地址：http://seata.io/zh-cn/
本次用的是0.9版本，不同版本配置方式不同，详情请参照官方文档

（1）seata-server-0.9.0.zip解压到指定目录并修改conf目录下的file.conf配置文件

先备份原始file.conf文件
主要修改：自定义事务组名称+事务日志存储模式为db+数据库连接信息
file.conf：
service模块：vgroup_mapping.my_test_tx_group = "fsp_tx_group"
store模块：

mode = "db"
 
  url = "jdbc:mysql://127.0.0.1:3306/seata"
  user = "root"
  password = "你自己的密码"

（2）mysql5.7数据库新建库seata
在seata库里建表，建表db_store.sql在seata-server-0.9.0seataconf目录里面
sql

-- the table to store GlobalSession data
drop table if exists `global_table`;
create table `global_table` (
  `xid` varchar(128)  not null,
  `transaction_id` bigint,
  `status` tinyint not null,
  `application_id` varchar(32),
  `transaction_service_group` varchar(32),
  `transaction_name` varchar(128),
  `timeout` int,
  `begin_time` bigint,
  `application_data` varchar(2000),
  `gmt_create` datetime,
  `gmt_modified` datetime,
  primary key (`xid`),
  key `idx_gmt_modified_status` (`gmt_modified`, `status`),
  key `idx_transaction_id` (`transaction_id`)
);
 
-- the table to store BranchSession data
drop table if exists `branch_table`;
create table `branch_table` (
  `branch_id` bigint not null,
  `xid` varchar(128) not null,
  `transaction_id` bigint ,
  `resource_group_id` varchar(32),
  `resource_id` varchar(256) ,
  `lock_key` varchar(128) ,
  `branch_type` varchar(8) ,
  `status` tinyint,
  `client_id` varchar(64),
  `application_data` varchar(2000),
  `gmt_create` datetime,
  `gmt_modified` datetime,
  primary key (`branch_id`),
  key `idx_xid` (`xid`)
);
 
-- the table to store lock data
drop table if exists `lock_table`;
create table `lock_table` (
  `row_key` varchar(128) not null,
  `xid` varchar(96),
  `transaction_id` long ,
  `branch_id` long,
  `resource_id` varchar(256) ,
  `table_name` varchar(32) ,
  `pk` varchar(36) ,
  `gmt_create` datetime ,
  `gmt_modified` datetime,
  primary key(`row_key`)
);

（3）修改seata-server-0.9.0seataconf目录下的registry.conf配置文件

registry {
  # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
  type = "nacos"
 
  nacos {
    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

（4）先启动Nacos端口号8848，再启动seata-server，softsseata-server-0.9.0seatabin目录下，双机seata-server.bat

三、订单/库存/账户业务数据库准备

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
SQL：

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=7 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=2 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=2 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
SQL：

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;

最终效果：

四、订单/库存/账户业务微服务准备

业务需求：下订单->减库存->扣余额->改（订单）状态

新建订单Order-Module，seata-order-service2001
pom依赖

   
        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-nacos-discovery
        
        
        
            com.alibaba.cloud
            spring-cloud-starter-alibaba-seata
            
                
                    seata-all
                    io.seata
                
            
        
        
            io.seata
            seata-all
            0.9.0
        
        
        
            org.springframework.cloud
            spring-cloud-starter-openfeign
        
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        
        
        
            mysql
            mysql-connector-java
            5.1.37
        
        
            com.alibaba
            druid-spring-boot-starter
            1.1.10
        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            2.0.0
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
            org.projectlombok
            lombok
            true

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: root
 
feign:
  hystrix:
    enabled: false
 
logging:
  level:
    io:
      seata: info
 
mybatis:
  mapperLocations: classpath:mapper/*.xml

实体类domain

CommonResult

@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

@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
}

Dao接口及实现

@Mapper
public interface OrderDao
{
    //新建订单
    void create(Order order);
 
    //修改订单状态，从零改为1
    void update(@Param("userId") Long userId,@Param("status") Integer status);
}

resources文件夹下新建mapper文件夹后添加
OrderMapper.xml



 

 
    
        
        
        
        
        
        
    
 
    
        insert into t_order (id,user_id,product_id,count,money,status)
        values (null,#{userId},#{productId},#{count},#{money},0);
    
 
 
    
        update t_order set status = 1
        where user_id=#{userId} and status = #{status};

Service接口及实现

OrderService

public interface OrderService{
    void create(Order order);
}

OrderServiceImpl

@Service
@Slf4j
public class OrderServiceImpl implements OrderService
{
    @Resource
    private OrderDao orderDao;
    @Resource
    private StorageService storageService;
    @Resource
    private AccountService accountService;
 
    
     
    @Override
    @GlobalTransactional(name = "fsp-create-order",rollbackFor = Exception.class)
    public void create(Order order){
        log.info("----->开始新建订单");
        //新建订单
        orderDao.create(order);
 
        //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");
 
        //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");
 
         
        //修改订单状态，从零到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");
 
    }
}

StorageService

@FeignClient(value = "seata-storage-service")
public interface StorageService{
    @PostMapping(value = "/storage/decrease")
    CommonResult decrease(@RequestParam("productId") Long productId, @RequestParam("count") Integer count);
}

AccountService

@FeignClient(value = "seata-account-service")
public interface AccountService{
    @PostMapping(value = "/account/decrease")
    CommonResult decrease(@RequestParam("userId") Long userId, @RequestParam("money") BigDecimal money);
}

Controller

 
@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

@Configuration
@MapperScan({"com.atguigu.springcloud.alibaba.dao"})
public class MyBatisConfig {
 
}

DataSourceProxyConfig

@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();
    }
 
}

主启动

@EnableDiscoveryClient
@EnableFeignClients
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)//取消数据源自动创建的配置
public class SeataOrderMainApp2001{
 
    public static void main(String[] args)
    {
        SpringApplication.run(SeataOrderMainApp2001.class, args);
    }
}

依次构建另外两个项目，并且在resources文件夹中加入seata的两个配置文件

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 = "default" #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 = "root"
    min-conn = 1
    max-conn = 3
    global.table = "global_table"
    branch.table = "branch_table"
    lock-table = "lock_table"
    query-limit = 100
  }
}
lock {
  ## the lock store mode: local、remote
  mode = "remote"
 
  local {
    ## store locks in user's database
  }
 
  remote {
    ## store locks in the seata's server
  }
}
recovery {
  #schedule committing retry period in milliseconds
  committing-retry-period = 1000
  #schedule asyn committing retry period in milliseconds
  asyn-committing-retry-period = 1000
  #schedule rollbacking retry period in milliseconds
  rollbacking-retry-period = 1000
  #schedule timeout retry period in milliseconds
  timeout-retry-period = 1000
}
 
transaction {
  undo.data.validation = true
  undo.log.serialization = "jackson"
  undo.log.save.days = 7
  #schedule delete expired undo_log in milliseconds
  undo.log.delete.period = 86400000
  undo.log.table = "undo_log"
}
 
## metrics settings
metrics {
  enabled = false
  registry-type = "compact"
  # multi exporters use comma divided
  exporter-list = "prometheus"
  exporter-prometheus-port = 9898
}
 
support {
  ## spring
  spring {
    # auto proxy the DataSource bean
    datasource.autoproxy = false
  }
}

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"
  }
}

五、进行测试

正常下单
http://localhost:2001/order/create?userid=1&producrid=1&counr=10&money=100
数据库情况

超时异常，没加@GlobalTransactional，AccountServiceImpl添加超时
故障情况:当库存和账户余额扣减后，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，添加@GlobalTransactional
OrderServiceImpl@GlobalTransactional，下单后数据库数据并没有任何改变

六、Seata之原理简介

（1）TC/TM/RM三大组件

（2）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)
换业务场景，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。

（3）AT模式如何做到对业务的无侵入

一阶段加载


二阶段提交

二阶段回滚


PS：所有代码的码云链接

https://gitee.com/dream_and_zen/cloud2020.git

欢迎分享，转载请注明来源：内存溢出

原文地址: https://www.outofmemory.cn/zaji/5687686.html

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