在后面一篇咱们介绍了Seata 分布式事务系列一: Seata 服务端搭建.
这一篇咱们应用Seata 进行一个 Dubbo 微服务分布式事务的示例. 本示例蕴含 4 个我的项目:
- API Rest服务, 对立对外的业务模块, 这里示例一个购物服务 purchase(). 其 Dubbo 身份为服务消费者.
- Account 账户微服务, 下单前需扣除账户余额. 其 Dubbo 身份为服务提供者.
- Order 订单微服务, 创立订单. 其 Dubbo 身份为服务消费者 + 提供者.
- Inventory 库存微服务, 创立订单前需扣除商品库存. 其 Dubbo 身份为服务提供者.
四者之间的调用关系如下图所示:
一. API 服务
API 模块为一个一般的 SpringBoot Web Restful API服务, 为 Dubbo 服务消费者. 在 purchase() 中, 启动全局事务.
1.1 maven依赖
<?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 http://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>2.1.5.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>fun.faceless.dubboshop.api</groupId> <artifactId>parent</artifactId> <packaging>pom</packaging> <version>1.0.0-SNAPSHOT</version> <name>api-center</name> <description>dubboshop api center</description> <properties> <java.version>1.8</java.version> <spring-boot.version>2.1.5.RELEASE</spring-boot.version> <spring.version>5.1.7.RELEASE</spring.version> <dubbo.version>2.7.7</dubbo.version> </properties> <dependencyManagement> <dependencies> <!-- springboot related --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>${spring-boot.version}</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <version>${spring-boot.version}</version> <scope>runtime</scope> </dependency> <!-- db data --> <!-- 对应 mybatis 3.5.5，从3.5.0开始反对mapper返回Optional --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.1.3</version> </dependency> <!-- https://mvnrepository.com/artifact/org.mybatis.dynamic-sql/mybatis-dynamic-sql --> <dependency> <groupId>org.mybatis.dynamic-sql</groupId> <artifactId>mybatis-dynamic-sql</artifactId> <version>1.1.4</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.16</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.29</version> </dependency> <!-- Redis --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> <version>${spring-boot.version}</version> </dependency> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-pool2</artifactId> <version>2.6.2</version> </dependency> <!--jackson依赖--> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.9.5</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.5</version> </dependency> <!-- rocketmq --> <!--<dependency> <groupId>org.apache.rocketmq</groupId> <artifactId>rocketmq-client</artifactId> <version>4.7.0</version> </dependency>--> <dependency> <groupId>org.apache.rocketmq</groupId> <artifactId>rocketmq-spring-boot-starter</artifactId> <version>2.1.0</version> </dependency> <!-- caching --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-cache</artifactId> <version>${spring-boot.version}</version> </dependency> <dependency> <groupId>org.ehcache</groupId> <version>3.6.3</version> <artifactId>ehcache</artifactId> </dependency> <dependency> <groupId>javax.cache</groupId> <artifactId>cache-api</artifactId> <version>1.1.0</version> </dependency> <!-- Seata --> <dependency> <groupId>io.seata</groupId> <artifactId>seata-spring-boot-starter</artifactId> <version>1.3.0</version> </dependency> <!-- Dubbo dependencies --> <dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo-bom</artifactId> <version>${dubbo.version}</version> <type>pom</type> </dependency> <dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo</artifactId> <version>${dubbo.version}</version> <exclusions> <exclusion> <groupId>org.apache.thrift</groupId> <artifactId>libthrift</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo-spring-boot-starter</artifactId> <version>${dubbo.version}</version> </dependency> <dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo-metadata-report-zookeeper</artifactId> <version>${dubbo.version}</version> </dependency> <!-- dubbo REST protocal --> <dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo-rpc-rest</artifactId> <version>${dubbo.version}</version> </dependency> <dependency> <groupId>org.apache.tomcat.embed</groupId> <artifactId>tomcat-embed-core</artifactId> <version>8.5.32</version> </dependency> <!-- Zookeeper dependencies--> <dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo-dependencies-zookeeper</artifactId> <version>2.7.1</version> <type>pom</type> <exclusions> <exclusion> <artifactId>log4j</artifactId> <groupId>log4j</groupId> </exclusion> <exclusion> <artifactId>slf4j-log4j12</artifactId> <groupId>org.slf4j</groupId> </exclusion> </exclusions> </dependency> <!-- inter-project modules --> <dependency> <groupId>fun.faceless.dubboshop</groupId> <artifactId>comms</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency> <dependency> <groupId>fun.faceless.dubboshop.inventory</groupId> <artifactId>dubboapi</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency> <dependency> <groupId>fun.faceless.dubboshop.account</groupId> <artifactId>dubboapi</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency> <dependency> <groupId>fun.faceless.dubboshop.order</groupId> <artifactId>dubboapi</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency> <!-- other dependencies --> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.8</version> <optional>true</optional> </dependency> <!-- testing related --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <version>${spring-boot.version}</version> </dependency> </dependencies> </dependencyManagement> <dependencies> <!-- 将下面通过 dependencyManagement 指定版本号的依赖依据须要放到这里... --> </dependencies>1.2 我的项目配置文件
在 application.yaml中配置 seata:
spring: # 这里省略spring相干的惯例配置... dubbo: # 注册核心配置 registry: id: dubboshop-registry address: zookeeper://<your_zk_host>:2181 group: dubbo simplified: true metadata-report: address: zookeeper://<your_zk_host>:2181 group: dubbo application: name: dubboshop-api id: dubboshop-api logger: slf4j# 这里 seata 未应用注册核心. 如果应用过seata: application-id: dubboshop-api # Seata 利用编号， tx-service-group: dubboshop-api-group # Seata 事务组编号，用于 TC 集群名 # Seata 服务配置项，对应 ServiceProperties 类 service: # 虚构组和分组的映射 vgroup-mapping: dubboshop-api-group: default # 这里 dubboshop-api-group 对应下面 tx-service-group 的值. # 分组和 Seata 服务的映射. 不实用 Nacos 注册核心时, 配置grouplist, 否则不须要该项. grouplist: default: <your_seata_server_host>:80911.3 业务代码
我的项目启动WebApplication:
@SpringBootApplication@RestController@ComponentScan("fun.faceless.dubboshop.api")public class WebApplication { public static void main(String[] args) { SpringApplication.run(WebApplication.class, args); } @GetMapping("/") public String home() { return String.format("<html>Welcome to %s</html>", "DubboShopApiCenter"); }}业务代码, 这里为了不便, 事务间接放在了OrderController中, 没有独自去写一个Service了.
@RestController@RequestMapping("/api")@Slf4jpublic class OrderController { // 在 dubbo 2.7.x 中, cluster="failfast" 存在bug, 无奈失常失效, 所以须要设置 retries=0. @Reference(protocol = "dubbo", cluster="failfast", retries=0) OrderProvider orderProvider; @Reference(protocol = "dubbo", cluster="failfast", retries=0) AccountCreditProvider accountCreditProvider; private String dubboConfigCenterAddr = "yyadmin:2181"; @PostMapping(value = "purchase") @GlobalTransactional // 留神这里启动全局事务 public Result purchase(@RequestParam int userId, @RequestParam int goodsId, @RequestParam int goodsNum) { log.info("以后 XID: {}", RootContext.getXID()); int unitCredit = 10; int creditAmount = goodsNum * unitCredit; accountCreditProvider.debit(userId, creditAmount); orderProvider.createOrder(userId, goodsId, goodsNum); return Result.succ("Order created successfully."); }}二. 其余微服务
其余微服务指 Account, Inventory, Order 3 个微服务项目. 三者的配置和形式都根本一样, 外围就是在相干 Service 上应用 @Transactional 进行本地事务管理. 此外, 能够通过 RootContext获取全局事务ID: xid.
2.1 Maven依赖
微服务项目的 dubbo 和 seata 无关依赖跟 api我的项目的依赖基本一致. 能够间接参考下面.
2.2 我的项目配置
各微服务项目 dubbo 和 seata 无关的配置也基本一致. 只不过这三者作为微服务提供者, dubbo 相干的会多一些 protocol 配置. 这里以 Order 我的项目为例:
# ========= Dubbo Provider ==============dubbo: # 配置核心, see: http://dubbo.apache.org/zh-cn/docs/user/configuration/config-center.html config-center: address: zookeeper://<your_zk_host>:2181 group: dubbo # 注册核心配置 registry: id: dubboshop-registry address: zookeeper://<your_zk_host>:2181 group: dubbo simplified: true check: true metadata-report: address: zookeeper://<your_zk_host>:2181 group: dubbo application: name: dubboshop-order id: dubboshop-order logger: slf4j # 示例多 Protocol, 这里反对 dubbo 和 rest 两种 Protocols. protocols: dubbo: name: dubbo server: netty4 port: 20884 accesslog: true rest: name: rest server: tomcat port: 8084 accesslog: true scan: # dubbo 服务提供者实现类所在包 base-packages: fun.faceless.dubboshop.order.dubboprovider# Seata 配置项，对应 SeataProperties 类seata: application-id: dubboshop-order # Seata 利用编号，默认为 ${spring.application.name} tx-service-group: dubboshop-order-group # Seata 事务组编号，用于 TC 集群名 # Seata 服务配置项，对应 ServiceProperties 类 service: # 虚构组和分组的映射 vgroup-mapping: dubboshop-order-group: default # 这里 dubboshop-order-group 对应 下面 tx-service-group 的值. # 分组和 Seata 服务的映射. 不实用 Nacos 注册核心时, 配置grouplist, 否则不须要该项. grouplist: default: <your_seata_server_host>:8091# 本来纯dubbo服务不须要配置 server.port, 不过 Seata 会主动启动 SpringBoot Web, 须要配置一个端口. 留神如果是同一主机上启动这几个服务, 这个端口取不同的值. 否则会报端口占用异样.server: port: 280842.3 业务代码
@Slf4j@Service(cluster="failfast", retries=0, timeout = 2000)public class OrderProviderImpl implements OrderProvider { // 本地长久化 DAO @Autowired private OrderDao orderDao; // Dubbo调用 InventoryProvider @Reference(protocol="dubbo", cluster="failfast", retries=0, timeout = 1500) private InventoryProvider inventoryProvider; /** * 调用Dubbo服务, 扣除库存. 而后提交数据库, 创立一个新订单. * * @param userId * @param goodsId * @param orderCount * @return 返回受影响的记录行数 */ @Override @Transactional // <- 留神这里须要本地事务 public int createOrder(int userId, int goodsId, int orderCount) { log.info("以后 XID: {}", RootContext.getXID()); Result debitResult = inventoryProvider.deduce(goodsId, orderCount); return this.saveOrder(userId, goodsId, orderCount); } private int saveOrder(int userId, int goodsId, int orderCount) { Order order = new Order(); order.setUserId(userId); order.setState((short) 10); order.setGoodsInfo(prepareNewGoodsInfo(goodsId, orderCount)); int recordsAffected = orderDao.createOrder(order); return recordsAffected; } // 省略其余业务代码}