目录

一、seata使用场景 

二、seata组成

三、seata服务端搭建

四、客户端使用seata

4.1 客户端增加undo_log表

4.2 客户端增加seata相关配置

4.3 客户端使用注解

五、测试

---

一、seata使用场景 

微服务中，一个业务涉及到多个微服务系统，每个微服务系统连接不同的数据库，要求数据一致性时使用。如下订单操作，调用下订单方法后，需要增加订单记录、减少产品库存；订单记录和产品库存 调用不同的微服务  数据存储在不同的数据库中；

调用下订单方法时，订单服务或库存服务任何一个出现问题，此方法执行失败，数据库记录需回滚。

理论支持：cap、base；

理论依据：二阶段提交法（准备、执行）；三阶段提交法（询问、准备、执行）；消息最终一致性；最大努力通知法；

解决方案：tcc（try-confirm-cancel）、sega、X/A等。

二、seata组成

seata是spring cloud生态中的分布式事务解决方案，包括seata服务端和客户端；

seata服务端是独立部署的；（seata担当事务协调器角色）

seata客户端，即每个微服务增加相关依赖和配置，使用@GlobalTransactional(rollbackFor = Exception.class)注解即可；

三、seata服务端搭建

1. 下载seata服务端包；

本文使用的是seata1.7.0版本的包。

2. 修改seata配置文件 application.yml，使用nacos注册seata服务，管理seata服务配置；

路径seata>conf,application.yml

#  Copyright 1999-2019 Seata.io Group.
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#  http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

server:
  port: 7091

spring:
  application:
    name: seata-server

logging:
  config: classpath:logback-spring.xml
  file:
    path: ${user.home}/logs/seata
  extend:
    logstash-appender:
      destination: 127.0.0.1:4560
    kafka-appender:
      bootstrap-servers: 127.0.0.1:9092
      topic: logback_to_logstash
console:
  user:
    username: seata
    password: seata

seata:
  config:
    # support: nacos 、 consul 、 apollo 、 zk  、 etcd3
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8948
      namespace:
      group: SEATA_GROUP
      username: nacos
      password: 
      context-path:
      ##if use MSE Nacos with auth, mutex with username/password attribute
      #access-key:
      #secret-key:
      data-id: seataServer.properties
  registry:
    # support: nacos 、 eureka 、 redis 、 zk  、 consul 、 etcd3 、 sofa
    type: nacos
    nacos:
      application: seata-server
      server-addr: 127.0.0.1:8948
      group: SEATA_GROUP
      namespace:
      cluster: default
      username: nacos
      password: 
      context-path:
      ##if use MSE Nacos with auth, mutex with username/password attribute
      #access-key:
      #secret-key:
  security:
    secretKey: 
    tokenValidityInMilliseconds: 1800000
    ignore:
      urls: /,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*.png,/**/*.jpeg,/**/*.ico,/api/v1/auth/login

在nacos中增加seata配置：

seataServer.properties配置文件：

#For details about configuration items, see https://seata.io/zh-cn/docs/user/configurations.html
#Transport configuration, for client and server
transport.type=TCP
transport.server=NIO
transport.heartbeat=true
transport.enableTmClientBatchSendRequest=false
transport.enableRmClientBatchSendRequest=true
transport.enableTcServerBatchSendResponse=false
transport.rpcRmRequestTimeout=30000
transport.rpcTmRequestTimeout=30000
transport.rpcTcRequestTimeout=30000
transport.threadFactory.bossThreadPrefix=NettyBoss
transport.threadFactory.workerThreadPrefix=NettyServerNIOWorker
transport.threadFactory.serverExecutorThreadPrefix=NettyServerBizHandler
transport.threadFactory.shareBossWorker=false
transport.threadFactory.clientSelectorThreadPrefix=NettyClientSelector
transport.threadFactory.clientSelectorThreadSize=1
transport.threadFactory.clientWorkerThreadPrefix=NettyClientWorkerThread
transport.threadFactory.bossThreadSize=1
transport.threadFactory.workerThreadSize=default
transport.shutdown.wait=3
transport.serialization=seata
transport.compressor=none

#Transaction routing rules configuration, only for the client
service.vgroupMapping.default_tx_group=default
#If you use a registry, you can ignore it
service.default.grouplist=127.0.0.1:8091
service.enableDegrade=false
service.disableGlobalTransaction=false

#Transaction rule configuration, only for the client
client.rm.asyncCommitBufferLimit=10000
client.rm.lock.retryInterval=10
client.rm.lock.retryTimes=30
client.rm.lock.retryPolicyBranchRollbackOnConflict=true
client.rm.reportRetryCount=5
client.rm.tableMetaCheckEnable=true
client.rm.tableMetaCheckerInterval=60000
client.rm.sqlParserType=druid
client.rm.reportSuccessEnable=false
client.rm.sagaBranchRegisterEnable=false
client.rm.sagaJsonParser=fastjson
client.rm.tccActionInterceptorOrder=-2147482648
client.tm.commitRetryCount=5
client.tm.rollbackRetryCount=5
client.tm.defaultGlobalTransactionTimeout=60000
client.tm.degradeCheck=false
client.tm.degradeCheckAllowTimes=10
client.tm.degradeCheckPeriod=2000
client.tm.interceptorOrder=-2147482648
client.undo.dataValidation=true
client.undo.logSerialization=jackson
client.undo.onlyCareUpdateColumns=true
server.undo.logSaveDays=7
server.undo.logDeletePeriod=86400000
client.undo.logTable=undo_log
client.undo.compress.enable=true
client.undo.compress.type=zip
client.undo.compress.threshold=64k
#For TCC transaction mode
tcc.fence.logTableName=tcc_fence_log
tcc.fence.cleanPeriod=1h

#Log rule configuration, for client and server
log.exceptionRate=100

#Transaction storage configuration, only for the server. The file, db, and redis configuration values are optional.
store.mode=db
store.lock.mode=db
store.session.mode=db
#Used for password encryption
store.publicKey=

#These configurations are required if the `store mode` is `db`. If `store.mode,store.lock.mode,store.session.mode` are not equal to `db`, you can remove the configuration block.
store.db.datasource=druid
store.db.dbType=mysql
store.db.driverClassName=com.mysql.cj.jdbc.Driver
store.db.url=jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true
store.db.user=root
store.db.password=
store.db.minConn=5
store.db.maxConn=30
store.db.globalTable=global_table
store.db.branchTable=branch_table
store.db.distributedLockTable=distributed_lock
store.db.queryLimit=100
store.db.lockTable=lock_table
store.db.maxWait=5000

#Transaction rule configuration, only for the server
server.recovery.committingRetryPeriod=1000
server.recovery.asynCommittingRetryPeriod=1000
server.recovery.rollbackingRetryPeriod=1000
server.recovery.timeoutRetryPeriod=1000
server.maxCommitRetryTimeout=-1
server.maxRollbackRetryTimeout=-1
server.rollbackRetryTimeoutUnlockEnable=false
server.distributedLockExpireTime=10000
server.xaerNotaRetryTimeout=60000
server.session.branchAsyncQueueSize=5000
server.session.enableBranchAsyncRemove=false
server.enableParallelRequestHandle=false

#Metrics configuration, only for the server
metrics.enabled=false
metrics.registryType=compact
metrics.exporterList=prometheus
metrics.exporterPrometheusPort=9898

3. 创建seata服务所需数据库表；

在seata script目录下找到sql脚本

执行sql语句建表：

-- -------------------------------- 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_status_gmt_modified` (`status` , `gmt_modified`),
    KEY `idx_transaction_id` (`transaction_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4;

-- 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 = utf8mb4;

-- 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),
    `status`         TINYINT      NOT NULL DEFAULT '0' COMMENT '0:locked ,1:rollbacking',
    `gmt_create`     DATETIME,
    `gmt_modified`   DATETIME,
    PRIMARY KEY (`row_key`),
    KEY `idx_status` (`status`),
    KEY `idx_branch_id` (`branch_id`),
    KEY `idx_xid` (`xid`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4;

CREATE TABLE IF NOT EXISTS `distributed_lock`
(
    `lock_key`       CHAR(20) NOT NULL,
    `lock_value`     VARCHAR(20) NOT NULL,
    `expire`         BIGINT,
    primary key (`lock_key`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4;

INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('AsyncCommitting', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('RetryCommitting', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('RetryRollbacking', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('TxTimeoutCheck', ' ', 0);

四、客户端使用seata

示例由三个服务组成，seataDemoWeb、demo-order、demo-product；

其中seataDemoWeb服务提供rest接口test，此接口调用demo-order和demo-product服务，增加订单记录，修改库存。

4.1 客户端增加undo_log表

demo-order和demo-product，两个服务对应的数据库均需增加undo_log表；

建表语句：

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;

4.2 客户端增加seata相关配置

seataDemoWeb、demo-order和demo-product在application.properties中增加seata配置

seata.enabled=true
seata.application-id=${spring.application.name}
seata.tx-service-group=seata-tx-group
seata.service.vgroup-mapping.seata-tx-group=default
seata.registry.type=nacos
seata.registry.nacos.server-addr=127.0.0.1:8948
seata.registry.nacos.username=nacos
seata.registry.nacos.password=
seata.registry.nacos.namespace=public
seata.registry.nacos.group=SEATA_GROUP
seata.registry.nacos.application=seata-server

pom增加seata依赖，完整pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.10.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>hj.example</groupId>
    <artifactId>productDemo</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>

    <properties>
        <lombok.version>1.18.24</lombok.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>hj.example</groupId>
            <artifactId>demoCommon</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.12</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
        </dependency>
        <!-- nacos -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>2.2.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
            <version>2.2.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-dubbo</artifactId>
            <version>2.2.5.RELEASE</version>
        </dependency>

        <!-- seata -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
            <version>2.2.5.RELEASE</version>
            <exclusions>
                <exclusion>
                    <groupId>io.seata</groupId>
                    <artifactId>seata-spring-boot-starter</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-spring-boot-starter</artifactId>
            <version>1.7.0</version>
        </dependency>
    </dependencies>
</project>

 

4.3 客户端使用注解

在seataDemoWeb服务中，增加@GlobalTransaction注解

package hj.example.seatademoweb.controller;

import com.baomidou.mybatisplus.extension.service.IService;
import hj.example.democommon.entity.DemoOrder;
import hj.example.democommon.entity.DemoProduct;
import hj.example.democommon.entity.StateEnum;
import hj.example.democommon.services.DemoOrderService;
import hj.example.democommon.services.DemoProductService;
import io.seata.spring.annotation.GlobalTransactional;
import org.apache.dubbo.config.annotation.DubboReference;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Random;

/**
 * @Description: TODO
 * @Author: 
 * @Date: 2023/8/29
 **/
@RestController
public class TestController {
    @DubboReference(interfaceName = "demoOrderService")
    private DemoOrderService demoOrderService;

    @DubboReference(interfaceName = "demoProductService")
    private DemoProductService demoProductService;

    @RequestMapping("/test")
    @GlobalTransactional(rollbackFor = Exception.class)
    public ResponseEntity<Object> test() {
        DemoOrder demoOrder =new DemoOrder();
        demoOrder.setAccountId("1");
        demoOrder.setState(StateEnum.NEW.name());
        demoOrderService.save(demoOrder);

        DemoProduct demoProduct = new DemoProduct();
        demoProduct.setNum(Math.random()*10000);
        demoProductService.save(demoProduct);
        return new ResponseEntity<>("success", HttpStatus.OK);
    }
}

五、测试

修改4.3中的代码，debug查看回滚

DemoProduct demoProduct = new DemoProduct();
demoProduct.setNum(1/0);
demoProductService.save(demoProduct);