springcloud+eureka整合分布式事务中间件seata-阿里云开发者社区

微信图片_20221212135637.jpg 今天继续给大家分享一下阿里的分布式事务中间件seata的使用，跟上篇文章《springboot多数据源整合分布式事务中间件seata》不一样的是，上篇文章是单服务绑定多数据源的分布式情况，而本文基于微服务下每个服务绑定一个数据源的场景，服务之间依靠eureka客户端feign进行通信。

注:seata有三种模式，AT模式、TCC模式和saga模式，上篇文章和本篇文章介绍的都是AT模式。感兴趣的同学可以参考官网进行了解这三种模式：

http://seata.io/en-us/docs/dev/mode/at-mode.html

环境搭建

还是先说一下本文使用的实验环境：

springboot：2.1.6.RELEASE

orm框架：mybatis

数据库：mysql

数据库连接池：HikariCP

seata server：1.3.0

springcloud:Greenwich.SR2

整个项目的架构如下：

微信图片_20221212135700.png

可以看到，项目中有order-server,account-server，storage-server这3个服务，每个服务绑定自己的数据库。这3个服务都注册到eureka上面，同时也都注册TM到seata-server。seata-server也注册到了eureka上。

首先我们启动eureka，这里监听8889端口，yml文件配置如下：

server:
  port: 8889
spring:
  application:
    name: eureka-server
#Eureka实例名，集群中根据这里相互识别
eureka:
  instance:
    hostname: localhost
#客户端
  client:
#是否开启注册服务，因为这里如果为true表示自己注册自己，而自己就是一个服务注册方，没必要自己注册自己
    register-with-eureka: false
#是否拉取服务列表，这里我只提供服务给别的服务。
    fetch-registry: false
#注册中心地址
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
#服务端：
  server:
    enable-self-preservation: false

接着我们启动seata server，由于seata server也要注册到eureka上面，我们需要修改seata server，把registry.conf文件修改为如下：

registry {
  # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
  type = "eureka"
  #省略无关的代码
  eureka {
    #我本地配置的eureka地址
    serviceUrl = "http://192.168.59.1:8889/eureka"
    application = "seata-server"
    weight = "1"
  }
  #省略其他代码

执行如下命令启动seata server:

./seata-server.sh -p 8091 -h 127.0.0.1 -m file

配置3个微服务，这里我们以order-server为例，先看yml文件，核心配置就是eureka、feign、mybatis和数据源，代码如下：

#配置eureka
eureka:
    instance:
        hostname: localhost
        prefer-ip-address: true
    client:
        serviceUrl:
            defaultZone: http://${eureka.instance.hostname}:8889/eureka/
feign:
    hystrix:
        enabled: false
    client:
        config:
            default:
                connectTimeout: 5000
                readTimeout: 10000
logging:
    level:
        io:
            seata: info
#配置mybatis
mybatis:
    mapperLocations: classpath:mapper/*.xml
    typeAliasesPackage: io.seata.sample.entity
server:
    port: 8180
spring:
    application:
        name: order-server
    cloud:
        alibaba:
            seata:
                tx-service-group: my_test_tx_group
                #配置数据源
    datasource:
        driver-class-name: com.mysql.jdbc.Driver
        password: 123456
        jdbcUrl: jdbc:mysql://192.168.59.1:3306/seata_order?useAffectedRows=true&serverTimezone=UTC&characterEncoding=utf-8
        username: root

registry.conf文件，最核心的就是type使用eureka，然后配置eureka地址和应用名称，部分代码如下：

registry {
  # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
  type = "eureka"
#省略其他代码
  eureka {
    serviceUrl = "http://localhost:8889/eureka"
    application = "order-server"
    weight = "1"
  }
#省略其他代码
file.conf文件只要改一下service就可以了，里面配置seata server地址，代码如下：
service {
  #transaction service group mapping
  vgroupMapping.my_test_tx_group = "seata-server"
  #only support when registry.type=file, please don't set multiple addresses
  default.grouplist = "192.168.59.132:8091"
  #degrade, current not support
  enableDegrade = false
  #disable seata
  disableGlobalTransaction = false
}

用这种方式配置account-server和storage-server，之后把3个服务都起来，启动成功后，访问eureka页面，地址如下：

http://localhost:8889/

这时我们能看到加上seata server一共4个服务都已经启动成功了，见下图：

微信图片_20221212135904.png

下面我贴一下整个项目的sql语句：

#########################seata_order库
use database seata_order;
CREATE TABLE `orders` (
  `id` mediumint(11) NOT NULL AUTO_INCREMENT,
  `user_id` int(11) DEFAULT NULL,
  `product_id` int(11) DEFAULT NULL,
  `COUNT` int(11) DEFAULT NULL COMMENT '数量',
  `pay_amount` decimal(10,2) DEFAULT NULL,
  `status` varchar(100) DEFAULT NULL,
  `add_time` datetime DEFAULT CURRENT_TIMESTAMP,
  `last_update_time` datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8
#########################seata_pay库
use database seata_pay;
DROP TABLE account;
CREATE TABLE `account` (
  `id` BIGINT(11) NOT NULL AUTO_INCREMENT 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',
  `balance` DECIMAL(10,0) DEFAULT '0' COMMENT '剩余可用额度',
  `last_update_time` DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
INSERT INTO `seata_pay`.`account` (`id`, `user_id`, `total`, `used`, `balance`) VALUES ('1', '1', '1000', '0', '100');
#########################seata_storage库
use database seata_storage;
CREATE TABLE `storage` (
  `id` BIGINT(11) NOT NULL AUTO_INCREMENT,
  `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',
  PRIMARY KEY (`id`)
) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
INSERT INTO `seata_storage`.`storage` (`id`, `product_id`, `total`, `used`, `residue`) VALUES ('1', '1', '100', '0', '100');
#########################下面的undo_log表前面三个库都需要创建
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,
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB AUTO_INCREMENT=14 DEFAULT CHARSET=utf8

至此，整个环境就搭建完成了，接着我们进行测试。我们先看下account和storage两张表的数据，其他表都是空，如下图：

account

微信图片_20221212135956.png

storage表

微信图片_20221212140013.png

测试

现在我们开始进行测试，有2个场景，正常commit和场景和异常rollback场景。我们向order-server发一个post请求，content如下：

{
  "userId":1,
  "productId":1,
  "count":1,
  "money":1,
  "payAmount":50
}

这时order-server执行成功，日志如下:

2020-08-15 16:31:53.704  INFO 57868 --- [nio-8181-exec-1] i.s.sample.service.AccountServiceImpl    : ------->扣减账户开始account中
2020-08-15 16:31:54.141  INFO 57868 --- [nio-8181-exec-1] i.s.sample.service.AccountServiceImpl    : ------->扣减账户结束account中
2020-08-15 16:31:54.141  INFO 57868 --- [nio-8181-exec-1] i.s.sample.service.AccountServiceImpl    : 修改订单状态开始
2020-08-15 16:31:54.309  INFO 57868 --- [nio-8181-exec-1] c.netflix.config.ChainedDynamicProperty  : Flipping property: order-server.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2020-08-15 16:31:54.344  INFO 57868 --- [nio-8181-exec-1] c.n.u.concurrent.ShutdownEnabledTimer    : Shutdown hook installed for: NFLoadBalancer-PingTimer-order-server
2020-08-15 16:31:54.345  INFO 57868 --- [nio-8181-exec-1] c.netflix.loadbalancer.BaseLoadBalancer  : Client: order-server instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=order-server,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null
2020-08-15 16:31:54.352  INFO 57868 --- [nio-8181-exec-1] c.n.l.DynamicServerListLoadBalancer      : Using serverListUpdater PollingServerListUpdater
2020-08-15 16:31:54.385  INFO 57868 --- [nio-8181-exec-1] c.netflix.config.ChainedDynamicProperty  : Flipping property: order-server.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2020-08-15 16:31:54.386  INFO 57868 --- [nio-8181-exec-1] c.n.l.DynamicServerListLoadBalancer      : DynamicServerListLoadBalancer for client order-server initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=order-server,current list of Servers=[10.192.86.60:8180],Load balancer stats=Zone stats: {defaultzone=[Zone:defaultzone;  Instance count:1;  Active connections count: 0;  Circuit breaker tripped count: 0;  Active connections per server: 0.0;]
},Server stats: [[Server:10.192.86.60:8180;  Zone:defaultZone;  Total Requests:0;  Successive connection failure:0;  Total blackout seconds:0;  Last connection made:Thu Jan 01 08:00:00 CST 1970;  First connection made: Thu Jan 01 08:00:00 CST 1970;  Active Connections:0;  total failure count in last (1000) msecs:0;  average resp time:0.0;  90 percentile resp time:0.0;  95 percentile resp time:0.0;  min resp time:0.0;  max resp time:0.0;  stddev resp time:0.0]
]}ServerList:org.springframework.cloud.netflix.ribbon.eureka.DomainExtractingServerList@5fa120e1
2020-08-15 16:31:54.562  INFO 57868 --- [nio-8181-exec-1] i.s.sample.service.AccountServiceImpl    : 修改订单状态结束：订单状态修改成功
2020-08-15 16:31:54.578  WARN 57868 --- [nio-8181-exec-1] c.a.c.seata.web.SeataHandlerInterceptor  : xid in change during RPC from 192.168.59.132:8091:37575557075451904 to null
2020-08-15 16:31:55.166  INFO 57868 --- [ch_RMROLE_1_1_8] i.s.c.r.p.c.RmBranchCommitProcessor      : rm client handle branch commit process:xid=192.168.59.132:8091:37575557075451904,branchId=37575566823014400,branchType=AT,resourceId=jdbc:mysql://192.168.59.1:3306/seata_pay,applicationData=null
2020-08-15 16:31:55.169  INFO 57868 --- [ch_RMROLE_1_1_8] io.seata.rm.AbstractRMHandler            : Branch committing: 192.168.59.132:8091:37575557075451904 37575566823014400 jdbc:mysql://192.168.59.1:3306/seata_pay null
2020-08-15 16:31:55.170  INFO 57868 --- [ch_RMROLE_1_1_8] io.seata.rm.AbstractRMHandler            : Branch commit result: PhaseTwo_Committed
2020-08-15 16:31:55.356  INFO 57868 --- [erListUpdater-0] c.netflix.config.ChainedDynamicProperty  : Flipping property: order-server.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647

这时我们再看下数据库的数据，如下图：

order表

微信图片_20221212140124.png

account表

微信图片_20221212140144.png

storage表

微信图片_20221212140204.png

容易迷惑我们的是，order表的pay_amount值是45.5，而不是50，这时因为account-server执行完成后，又调用了order-server，执行了更新操作，代码如下：

public void decrease(Long userId, BigDecimal payAmount) {
    LOGGER.info("------->扣减账户开始account中");
    //模拟超时异常，全局事务回滚
    //try {
    //    Thread.sleep(30*1000);
    //} catch (InterruptedException e) {
    //    e.printStackTrace();
    //}
    accountDao.decrease(userId,payAmount);
    LOGGER.info("------->扣减账户结束account中");
    //修改订单状态，此调用会导致调用成环
    LOGGER.info("修改订单状态开始");
    String mes = orderApi.update(userId, payAmount.multiply(new BigDecimal("0.09")),0);
    LOGGER.info("修改订单状态结束：{}",mes);
}