[Java知识库]SpringCloud Alibaba环境集成之seata

前言

本文依托于

• SpringCloud Alibaba环境集成之nacos
• SpringCloud Alibaba环境集成之sentinel

在SpringCloud Alibaba的使用过程中，我总结为如下步骤：

• 下载并启动服务端
• 客户端引入spring-cloud-starter-alibaba的jar包
• 客户端properties或yml加入相关配置
• 客户端加上相应的注解开启功能
• 服务端增加相应配置
• 数据持久化，服务端集群部署

seata服务端

1.下载seata

在下面github地址找到最新版的seata下载源码和jar包，源码中有配置文件后续有用。

https://github.com/seata/seata/releases

2.修改file.conf

seata默认是file方式保存数据，设置默认组，还有超时时间。
在文件最下方添加下面的配置，更详细的配置见官网：

https://github.com/seata/seata-samples/blob/master/doc/quick-integration-with-spring-cloud.md

service {
  #vgroup->rgroup
  #vgroupMapping.my_test_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"
}

3.单机启动seata服务

seata-server.bat

seata客户端

1.引入jar

<!--引入 seata 依赖-->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
</dependency>

<!-- 连接mysql数据库 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.29</version>
</dependency>

<!-- 引入mybatis -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.0</version>
</dependency>

2.properties加入配置

# seata配置 file
seata.enabled=true
seata.config.type=file
seata.registry.type=file
#seata.service.grouplist.default=192.168.43.11:8091
seata.service.default.grouplist=192.168.43.11:8091
seata.service.enableDegrade=false
seata.service.disableGlobalTransaction=false
# 事务分组
spring.cloud.alibaba.seata.tx-service-group=${spring.application.name}-group
# vgroupMapping后名称修改为上面的事务分组的value值
seata.service.vgroupMapping.springcloud-alibaba-consumer-group=default

# 事务分组
spring.cloud.alibaba.seata.tx-service-group=${spring.application.name}-group

# 连接数据库
spring.datasource.url=jdbc:mysql://192.168.43.11:3306/order?useUnicode=true&rewriteBatchedStatements=true
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

# 指定 mapper.xml 的位置
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml

3.db

实现全局事务，客户端的数据库需要创建undo_log表，
文件在seata-1.4.2\script\client\at\db\mysql.sql下

CREATE TABLE `undo_log` (
  `branch_id` bigint(20) NOT NULL COMMENT 'branch transaction id',
  `xid` varchar(128) NOT NULL COMMENT 'global transaction id',
  `context` varchar(128) NOT NULL COMMENT 'undo_log context,such as serialization',
  `rollback_info` longblob NOT NULL COMMENT 'rollback info',
  `log_status` int(11) NOT NULL COMMENT '0:normal status,1:defense status',
  `log_created` datetime(6) NOT NULL COMMENT 'create datetime',
  `log_modified` datetime(6) NOT NULL COMMENT 'modify datetime',
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='AT transaction mode undo table';

测试seata

实现一个下订单功能，分别消费订单服务，用户服务，商品服务。

1.db

主要有用户表，商品表，订单表，订单商品表

CREATE TABLE `t_order` (
  `orderid` int(10) NOT NULL AUTO_INCREMENT COMMENT '订单id',
  `amount` decimal(10,2) DEFAULT '0.00' COMMENT '金额',
  `userid` int(10) DEFAULT NULL COMMENT '会员id',
  PRIMARY KEY (`orderid`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8mb4 COMMENT='订单表';

CREATE TABLE `t_orderplu` (
  `orderid` int(10) NOT NULL COMMENT '订单id',
  `pluid` int(10) NOT NULL COMMENT '商品id',
  `sno` int(10) NOT NULL COMMENT '序号',
  `qty` decimal(10,2) NOT NULL COMMENT '数量',
  `amount` decimal(10,2) NOT NULL COMMENT '金额',
  PRIMARY KEY (`orderid`,`pluid`,`sno`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='订单商品表';

CREATE TABLE `t_plu` (
  `pluid` int(10) NOT NULL COMMENT '商品id',
  `pluname` varchar(50) DEFAULT NULL COMMENT '商品名称',
  `price` decimal(10,2) DEFAULT '0.00' COMMENT '价格',
  `qty` decimal(10,2) DEFAULT '0.00' COMMENT '库存数量',
  PRIMARY KEY (`pluid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='商品表';

CREATE TABLE `t_user` (
  `userid` int(10) NOT NULL COMMENT '用户id',
  `username` varchar(50) DEFAULT NULL COMMENT '用户名',
  `money` decimal(10,2) DEFAULT '0.00' COMMENT '余额',
  PRIMARY KEY (`userid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='用户表';

2.消费者逻辑代码

1.在接口处通过feign分别调用用户服务，订单服务，商品服务。
2.使用@GlobalTransactional实现全局事务

/**
 * @author: kqyin
 * @date: 2022/5/6 10:38
 * @Description: 下订单
 */
@RestController
@RequestMapping("/place")
public class PlaceOrderController {

    @Autowired
    private OrderFeignService orderFeignService;

    @Autowired
    private PluFeignService pluFeignService;

    @Autowired
    private UserFeignService userFeignService;


    /**
     * @Author kqyin
     * @Date 2022/5/6 10:40
     * @Description 下订单
     */
    @RequestMapping("/order")
    @GlobalTransactional(rollbackFor = {Exception.class, RuntimeException.class})
    public boolean placeOrder(@RequestParam("userId") int userId, @RequestParam("pluId") int pluId) {
        User user = userFeignService.queryUserById(userId);
        if (user == null) {
            return false;
        }
        Plu plu = pluFeignService.queryPluById(pluId);
        if (plu == null) {
            return false;
        }
        if (plu.getQty().compareTo(BigDecimal.ONE) < 0) {
            return false;
        }
        if (plu.getPrice().compareTo(user.getMoney()) > 0) {
            return false;
        }
        OrderPlu orderPlu = new OrderPlu();
        orderPlu.setQty(BigDecimal.ONE);
        orderPlu.setPluId(pluId);
        orderPlu.setAmount(plu.getPrice());
        Order order = new Order();
        order.setUserId(userId);
        order.setAmount(plu.getPrice());
        List<OrderPlu> pluList = new ArrayList<>();
        pluList.add(orderPlu);
        order.setPluList(pluList);
        boolean flag = orderFeignService.createOrder(order);
        if (flag) {
            userFeignService.reduceMoney(userId, plu.getPrice());
            pluFeignService.reduceQty(BigDecimal.ONE, pluId);
        }
        return true;
    }
}

/**
 * @author: kqyin
 * @date: 2022/5/6 10:40
 * @Description:
 */
@FeignClient(value = "springcloud-alibaba-provider1")
public interface OrderFeignService {
    @RequestMapping("/order/createOrder")
    boolean createOrder(@RequestBody Order order);
}

/**
 * @author: kqyin
 * @date: 2022/5/6 10:42
 * @Description: 商品服务
 */
@FeignClient(value = "springcloud-alibaba-provider2")
public interface PluFeignService {
    @RequestMapping("/plu/queryPluById")
    Plu queryPluById(@RequestParam("pluId") int pluId);

    @RequestMapping("/plu/reduceQty")
    void reduceQty(@RequestParam("qty") BigDecimal qty, @RequestParam("pluId") int pluId);
}

/**
 * @author: kqyin
 * @date: 2022/5/6 10:48
 * @Description: 会员服务
 */
@FeignClient(value = "springcloud-alibaba-provider3")
public interface UserFeignService {
    @RequestMapping(value = "/user/queryUserById")
    User queryUserById(@RequestParam("userId") int userId);

    @RequestMapping(value = "/user/reduceMoney")
    void reduceMoney(@RequestParam("userId") int userId, @RequestParam("money") BigDecimal money);
}

3.订单服务逻辑代码

/**
 * @author: kqyin
 * @date: 2022/5/6 14:53
 * @Description:
 */
@RestController
@RequestMapping("/order")
public class OrderController {

    @Autowired
    private OrderService orderService;

    @RequestMapping("/createOrder")
    public boolean createOrder(@RequestBody Order order){
        int orderId = orderService.insertOrder(order);
        order.setOrderId(orderId);
        orderService.insertOrderPlu(orderId, order.getPluList());
        return true;
    }
}

<?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.ykq.springcloudalibabaprovider.mapper.OrderMapper">
    <insert id="insertOrder"  useGeneratedKeys="true" keyProperty="orderId" parameterType="com.ykq.springcloudalibabaentity.entity.Order">
        insert into t_order(orderId,
                            userId,
                            amount
                           )
                     values(null,
                            #{userId,jdbcType=INTEGER},
                            #{amount,jdbcType=NUMERIC}
                           )
    </insert>

    <insert id="insertOrderPlu">
        insert into t_orderplu(orderId,
                               pluId,
                               sno,
                               qty,
                               amount
                              )
                        values
        <foreach item="plu" index="index" collection="pluList" separator=",">
                              (#{orderId,jdbcType=INTEGER},
                               #{plu.pluId,jdbcType=INTEGER},
                               #{index},
                               #{plu.qty,jdbcType=NUMERIC},
                               #{plu.amount,jdbcType=NUMERIC}
                              )
        </foreach>
    </insert>
</mapper>

4.商品服务逻辑代码

/**
 * @author: kqyin
 * @date: 2022/5/6 14:37
 * @Description: 商品服务
 */
@RestController
@RequestMapping("/plu")
public class PluController {

    @Autowired
    private PluService pluService;

    /**
     * @Author kqyin
     * @Date 2022/5/6 14:41
     * @Description 根据id查询商品
     */
    @RequestMapping("/queryPluById")
    public Plu queryPluById(@RequestParam("pluId") int pluId) {
        return pluService.queryPluById(pluId);
    }

    /**
     * @Author kqyin
     * @Date 2022/5/6 16:30
     * @Description 减库存
     */
    @RequestMapping("/reduceQty")
    public void reduceQty(@RequestParam("qty") BigDecimal qty, @RequestParam("pluId") int pluId) {
        pluService.reduceQty(qty, pluId);
    }
}

<?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.ykq.springcloudalibabaprovider.mapper.PluMapper">
    <select id="queryPluById" resultType="com.ykq.springcloudalibabaentity.entity.Plu">
        select pluid,
               pluname,
               price,
               qty
          from t_plu
         where pluid = #{pluId,jdbcType=INTEGER}
    </select>

    <update id="reduceQty">
        update t_plu
           set qty = qty - #{qty,jdbcType=NUMERIC}
         where pluid = #{pluId,jdbcType=INTEGER}
    </update>
</mapper>

5.用户服务逻辑代码

/**
 * @author: kqyin
 * @date: 2022/5/6 13:37
 * @Description: 会员服务
 */
@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;
    
    /**
     * @Author kqyin
     * @Date 2022/5/6 13:42
     * @Description 根据id获取会员信息
     */
    @RequestMapping("/queryUserById")
    public User queryUserById(@RequestParam("userId") int userId) {
        return userService.queryUserById(userId);
    }

    /**
     * @Author kqyin
     * @Date 2022/5/6 16:33
     * @Description 扣钱
     */
    @RequestMapping("/reduceMoney")
    public void reduceMoney(@RequestParam("userId") int userId, @RequestParam("money") BigDecimal money) {
        userService.reduceMoney(userId, money);
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ykq.springcloudalibabaprovider.mapper.UserMapper">

    <select id="queryUserById" resultType="com.ykq.springcloudalibabaentity.entity.User">
        select userId,
               userName,
               money
          from t_user
         where userid = #{userId,jdbcType=INTEGER}
    </select>

    <update id="reduceMoney">
        update t_user
           set money = money - #{money,jdbcType=NUMERIC}
         where userId = #{userId,jdbcType=INTEGER}
    </update>
    
</mapper>

6.测试

（1）正常场景

可以看到事务提交成功 commit status: Committed

2022-05-10 14:41:47.884  INFO 26612 --- [nio-9001-exec-1] io.seata.tm.TransactionManagerHolder     : TransactionManager Singleton io.seata.tm.DefaultTransactionManager@16f40970
2022-05-10 14:41:47.894  INFO 26612 --- [Send_TMROLE_1_1] i.s.c.r.netty.NettyClientChannelManager  : will connect to 192.168.43.11:8091
2022-05-10 14:41:47.895  INFO 26612 --- [Send_TMROLE_1_1] i.s.core.rpc.netty.NettyPoolableFactory  : NettyPool create channel to transactionRole:TMROLE,address:192.168.43.11:8091,msg:< RegisterTMRequest{applicationId='springcloud-alibaba-consumer', transactionServiceGroup='springcloud-alibaba-consumer-group'} >
2022-05-10 14:41:47.904  INFO 26612 --- [Send_TMROLE_1_1] i.s.c.rpc.netty.TmNettyRemotingClient    : register TM success. client version:1.3.0, server version:1.4.2,channel:[id: 0xe3e04122, L:/192.168.43.11:53659 - R:/192.168.43.11:8091]
2022-05-10 14:41:47.904  INFO 26612 --- [Send_TMROLE_1_1] i.s.core.rpc.netty.NettyPoolableFactory  : register success, cost 5 ms, version:1.4.2,role:TMROLE,channel:[id: 0xe3e04122, L:/192.168.43.11:53659 - R:/192.168.43.11:8091]
2022-05-10 14:41:48.189  INFO 26612 --- [nio-9001-exec-1] i.seata.tm.api.DefaultGlobalTransaction  : Begin new global transaction [2.0.0.1:8091:261469811311718401]
2022-05-10 14:42:09.028  INFO 26612 --- [nio-9001-exec-1] i.seata.tm.api.DefaultGlobalTransaction  : [2.0.0.1:8091:261469811311718401] commit status: Committed
2022-05-10 14:42:38.901  INFO 26612 --- [nio-9001-exec-2] i.seata.tm.api.DefaultGlobalTransaction  : Begin new global transaction [2.0.0.1:8091:261469811311718406]
2022-05-10 14:42:39.033  INFO 26612 --- [nio-9001-exec-2] i.seata.tm.api.DefaultGlobalTransaction  : [2.0.0.1:8091:261469811311718406] commit status: Committed

（2）异常场景

修改商品服务减库存为抛异常，可以看到 rollback status: Rollbacked

/**
 * @Author kqyin
 * @Date 2022/5/6 16:30
 * @Description 减库存
 */
@RequestMapping("/reduceQty")
public void reduceQty(@RequestParam("qty") BigDecimal qty, @RequestParam("pluId") int pluId) {
    throw new RuntimeException();
    // pluService.reduceQty(qty, pluId);
}

2022-05-10 14:53:53.337  INFO 26612 --- [nio-9001-exec-1] i.seata.tm.api.DefaultGlobalTransaction  : Begin new global transaction [2.0.0.1:8091:261469811311718414]
2022-05-10 14:53:56.093  INFO 26612 --- [nio-9001-exec-1] i.seata.tm.api.DefaultGlobalTransaction  : [2.0.0.1:8091:261469811311718414] rollback status: Rollbacked

seata整合nacos，进行持久化

1.修改服务端registry.conf

修改注册和配置方式为nacos，指定nacos地址。

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

  nacos {
    application = "seata-server"
    serverAddr = "192.168.43.11:8000"
    group = "SEATA_GROUP"
    namespace = ""
    cluster = "default"
    username = "nacos"
    password = "nacos"
  }
}

config {
  # file、nacos 、apollo、zk、consul、etcd3
  type = "nacos"

  nacos {
    serverAddr = "192.168.43.11:8000"
    namespace = ""
    group = "SEATA_GROUP"
    username = "nacos"
    password = "nacos"
    dataId = "seataServer.properties"
  }
}

2.修改客户端application.properties配置

修改seata.config.type和seata.registry.type的值为nacos，其他的为新增配置

# 配置中心
seata.config.type=nacos
seata.config.nacos.group=SEATA_GROUP
seata.config.nacos.username=nacos
seata.config.nacos.password=nacos
seata.config.nacos.server-addr=192.168.43.11:8000

# 注册中心
seata.registry.type=nacos
seata.registry.nacos.group=SEATA_GROUP
seata.registry.nacos.username=nacos
seata.registry.nacos.password=nacos
seata.registry.nacos.server-addr=192.168.43.11:8000
seata.registry.nacos.application=seata-server

3.创建数据库seata

脚本路径在之前下载的源码seata-1.4.2\script\server\db下

-- -------------------------------- The script used when storeMode is 'db' --------------------------------
-- the table to store GlobalSession data
CREATE TABLE IF NOT EXISTS `global_table`
(
    `xid`                       VARCHAR(128) NOT NULL,
    `transaction_id`            BIGINT,
    `status`                    TINYINT      NOT NULL,
    `application_id`            VARCHAR(32),
    `transaction_service_group` VARCHAR(32),
    `transaction_name`          VARCHAR(128),
    `timeout`                   INT,
    `begin_time`                BIGINT,
    `application_data`          VARCHAR(2000),
    `gmt_create`                DATETIME,
    `gmt_modified`              DATETIME,
    PRIMARY KEY (`xid`),
    KEY `idx_gmt_modified_status` (`gmt_modified`, `status`),
    KEY `idx_transaction_id` (`transaction_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

-- the table to store BranchSession data
CREATE TABLE IF NOT EXISTS `branch_table`
(
    `branch_id`         BIGINT       NOT NULL,
    `xid`               VARCHAR(128) NOT NULL,
    `transaction_id`    BIGINT,
    `resource_group_id` VARCHAR(32),
    `resource_id`       VARCHAR(256),
    `branch_type`       VARCHAR(8),
    `status`            TINYINT,
    `client_id`         VARCHAR(64),
    `application_data`  VARCHAR(2000),
    `gmt_create`        DATETIME(6),
    `gmt_modified`      DATETIME(6),
    PRIMARY KEY (`branch_id`),
    KEY `idx_xid` (`xid`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

-- the table to store lock data
CREATE TABLE IF NOT EXISTS `lock_table`
(
    `row_key`        VARCHAR(128) NOT NULL,
    `xid`            VARCHAR(128),
    `transaction_id` BIGINT,
    `branch_id`      BIGINT       NOT NULL,
    `resource_id`    VARCHAR(256),
    `table_name`     VARCHAR(32),
    `pk`             VARCHAR(36),
    `gmt_create`     DATETIME,
    `gmt_modified`   DATETIME,
    PRIMARY KEY (`row_key`),
    KEY `idx_branch_id` (`branch_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

4.上传seata相关配置到nacos

（1）修改config.txt配置文件

配置文件在源码 seata-1.4.2\script\config-center\config.txt
在文件最下方添加下列配置，可以覆盖上面已有的相同配置，或者修改已有的配置的value值。
注意：service.vgroupMapping后的名称是自定义的，没有或错误会导致no available service ‘null’ found, please make sure registry config correct

store.mode=db
store.db.dbType=mysql
store.db.driverClassName=com.mysql.jdbc.Driver
store.db.url=jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true
store.db.user=root
store.db.password=123456


service.vgroupMapping.springcloud-alibaba-consumer-group=default
service.vgroupMapping.springcloud-alibaba-provider1-group=default
service.vgroupMapping.springcloud-alibaba-provider2-group=default
service.vgroupMapping.springcloud-alibaba-provider3-group=default

（2）上传config.txt文件内容至nacos

在 seata-1.4.2\script\config-center\nacos 目录下，右键鼠标选择 Git Bush Here，在弹出的 Git 命令窗口中执行以下命令，将 config.txt 中的配置上传到 Nacos 配置中心。

sh nacos-config.sh -h 127.0.0.1 -p 8000  -g SEATA_GROUP -u nacos -w nacos

（3）在nacos中查看

5.no available service ‘null’ found, please make sure registry config correct

虽然在application.properties中配置了service.vgroupMapping，但是看源码，可以发现是通过nacos拉取配置的。我们打断点跟踪一下。

（1）NettyClientChannelManager

（2）NacosRegistryServiceImpl

（3）NacosConfiguration

6.begin global request failed. xid=null, msg=Data truncation: Data too long for column ‘transaction_service_group’ at row 1

这是由于设置的tx-service-group的value太长，修改表字段长度

seata集群

只需要更换端口启动多个seata即可，之前一直在纠结配置的默认地址只有一个端口的服务，为啥不需要变。这是因为还配置了seata.registry.nacos.application=seata-server，根据服务名称在nacos可以找到多个服务。

（1）8091服务

seata-server.bat -p 8091 -n 1

可以看到8091的服务，所有服务都注册进来

（2）8092服务

seata-server.bat -p 8092 -n 2

nacos上的实例数也有两个

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