分布式事务两阶段提交——Eureka+Seata方案

分布式事务两阶段提交——Nacos+Seata方案

前言

在微服务的大环境下，服务按照业务维度拆分之后会遇到事务不一致问题，Seata的开源填补了两阶段提交这种模式，并且无业务代码的侵入，这里采用eureka集群整合Seata。

一、Eureka集群搭建

1、修改hosts文件映射

127.0.0.1 eureka-server1.com 127.0.0.1 eureka-server2.com

2、创建eureka-server工程，引入Maven依赖

<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.2.10.RELEASE</version> <relativePath/> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Hoxton.SR8</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build>

3、application.properties文件

• 1)application.properties

spring.profiles.active=eureka-server1

• 2)application-eureka-server1.properties

# Eureka Server服务端口 server.port=9090 # 取消服务器自我注册，就是Eureka Server也可以被更高层的服务器来管理 eureka.client.register-with-eureka=false # 注册中心的服务器，没有必要再去检索服务 eureka.client.fetch-registry=false # 单机 hostname: localhost #eureka注册中心实例名称 eureka.instance.hostname=eureka-server1.com # Eureka Server 服务URL，用于客户端注册 #设置与Eureka注册中心交互的地址，查询服务和注册服务用到 #集群 eureka.client.service-url.defaultZone=http://eureka-server2.com:9091/eureka/ #单机 #eureka.client.serverUrl.defaultZone=http://localhost:${server.port}/eureka/

• 3)application-eureka-server2.properties

# Eureka Server服务端口 server.port=9091 # 取消服务器自我注册，就是Eureka Server也可以被更高层的服务器来管理 eureka.client.register-with-eureka=false # 注册中心的服务器，没有必要再去检索服务 eureka.client.fetch-registry=false # 单机 hostname: localhost #eureka注册中心实例名称 eureka.instance.hostname=eureka-server2.com # Eureka Server 服务URL，用于客户端注册 #设置与Eureka注册中心交互的地址，查询服务和注册服务用到 #集群 eureka.client.service-url.defaultZone=http://eureka-server1.com:9090/eureka/ #单机 #eureka.client.serverUrl.defaultZone=http://localhost:${server.port}/eureka/

注意，多台eureka-server服务，只需要修改eureka.instance.hostname和eureka.client.service-url.defaultZone

4、新建EurekaServerApplication启动类

@SpringBootApplication @EnableEurekaServer public class EurekaServerApplication { public static void main(String[] args) { SpringApplication.run(EurekaServerApplication.class,args); } }

5、启动eureka-server服务

二、Seata配置

2.1、Seata服务端（TC）部署

下载Seata服务端压缩包：https://github.com/seata/seata/releases

2.2、Seata配置

• 1、修改conf目录中 flie.conf 文件，修改事务日志存储模式为 db 及数据库连接信息，且新增service模块，如下：

transport { # tcp udt unix-domain-socket type = "TCP" #NIO NATIVE server = "NIO" #enable heartbeat heartbeat = true # the client batch send request enable enableClientBatchSendRequest = false #thread factory for netty threadFactory { bossThreadPrefix = "NettyBoss" workerThreadPrefix = "NettyServerNIOWorker" serverExecutorThreadPrefix = "NettyServerBizHandler" shareBossWorker = false clientSelectorThreadPrefix = "NettyClientSelector" clientSelectorThreadSize = 1 clientWorkerThreadPrefix = "NettyClientWorkerThread" # netty boss thread size,will not be used for UDT bossThreadSize = 1 #auto default pin or 8 workerThreadSize = "default" } shutdown { # when destroy server, wait seconds wait = 3 } serialization = "seata" compressor = "none" } #这里手动加入service模块 service { #transaction service group mapping #修改，可不改,my_test_tx_group 前缀建议为各微服务名。 vgroup_mapping.seata_eureka_bank1_group = "seata-server" vgroup_mapping.seata_eureka_bank2_group = "seata-server" #only support when registry.type=file, please don't set multiple addresses # 此服务的地址 default.grouplist = "127.0.0.1:8091" #disable seata disableGlobalTransaction = false } ## transaction log store, only used in server side store { ## store mode: file、db mode = "db" ## file store property file { ## store location dir dir = "sessionStore" # branch session size , if exceeded first try compress lockkey, still exceeded throws exceptions maxBranchSessionSize = 16384 # globe session size , if exceeded throws exceptions maxGlobalSessionSize = 512 # file buffer size , if exceeded allocate new buffer fileWriteBufferCacheSize = 16384 # when recover batch read size sessionReloadReadSize = 100 # async, sync flushDiskMode = async } ## database store property db { ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp) etc. datasource = "druid" ## mysql/oracle/postgresql/h2/oceanbase etc. dbType = "mysql" driverClassName = "com.mysql.jdbc.Driver" url = "jdbc:mysql://localhost:3306/seata" user = "root" password = "yibo" minConn = 5 maxConn = 30 globalTable = "global_table" branchTable = "branch_table" lockTable = "lock_table" queryLimit = 100 } } ## server configuration, only used in server side server { recovery { #schedule committing retry period in milliseconds committingRetryPeriod = 1000 #schedule asyn committing retry period in milliseconds asynCommittingRetryPeriod = 1000 #schedule rollbacking retry period in milliseconds rollbackingRetryPeriod = 1000 #schedule timeout retry period in milliseconds timeoutRetryPeriod = 1000 } undo { logSaveDays = 7 #schedule delete expired undo_log in milliseconds logDeletePeriod = 86400000 } #check auth enableCheckAuth = true #unit ms,s,m,h,d represents milliseconds, seconds, minutes, hours, days, default permanent maxCommitRetryTimeout = "-1" maxRollbackRetryTimeout = "-1" rollbackRetryTimeoutUnlockEnable = false } ## metrics configuration, only used in server side metrics { enabled = false registryType = "compact" # multi exporters use comma divided exporterList = "prometheus" exporterPrometheusPort = 9898 }

由于我们使用了db模式存储事务日志，所以我们需要创建一个seata数据库，Seata数据库表初始化脚本：https://github.com/seata/seata/tree/1.1.0/script/server/db

2.3、修改注册中心和配置中心，使用eureka作为注册中心、直接使用file.conf配置文件存储seata规则，即修改 conf目录中 registry.conf 文件，如下：

registry { # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa type = "eureka" nacos { application = "seata-server" serverAddr = "127.0.0.1:8848" group = "SEATA_GROUP" namespace = "" cluster = "default" username = "" password = "" } eureka { serviceUrl = "http://eureka-server1.com:9090/eureka/,http://eureka-server2.com:9091/eureka/" application = "seata-server" weight = "1" } redis { serverAddr = "localhost:6379" db = 0 password = "" cluster = "default" timeout = 0 } zk { cluster = "default" serverAddr = "127.0.0.1:2181" sessionTimeout = 6000 connectTimeout = 2000 username = "" password = "" } 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 = "127.0.0.1:8848" namespace = "" group = "SEATA_GROUP" username = "" password = "" } consul { serverAddr = "127.0.0.1:8500" } apollo { appId = "seata-server" apolloMeta = "http://192.168.1.204:8801" namespace = "application" } zk { serverAddr = "127.0.0.1:2181" sessionTimeout = 6000 connectTimeout = 2000 username = "" password = "" } etcd3 { serverAddr = "http://localhost:2379" } file { name = "file.conf" } }

2.4、启动seata-server，如下：

三、各微服务配置

3.1、引入maven依赖

<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.2.10.RELEASE</version> <relativePath/> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-alibaba-seata</artifactId> <version>2.2.0.RELEASE</version> <exclusions> <exclusion> <groupId>io.seata</groupId> <artifactId>seata-all</artifactId> </exclusion> <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>1.3.0</version> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper-spring-boot-starter</artifactId> <version>2.1.5</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.18</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.12</version> <scope>provided</scope> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Hoxton.SR8</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.6</version> <configuration> <configurationFile> ${basedir}/src/main/resources/generator/generatorConfig.xml </configurationFile> <overwrite>true</overwrite> <verbose>true</verbose> </configuration> <dependencies> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.18</version> </dependency> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper</artifactId> <version>4.1.5</version> </dependency> </dependencies> </plugin> </plugins> </build>

3.2、分别在各业务数据库中创建undo_log表，此表为seata框架使用，sql地址：https://github.com/seata/seata/tree/develop/script/client/at/db

3.3、配置application.properties文件

# 应用名 spring.application.name=eureka-seata-bank1 server.port=8080 #表示是否将自己注册进EurekaServer默认为true eureka.client.register-with-eureka=true #是否从EurekaServer抓取已有的注册信息，默认为true，单节点无所谓，集群必须设置为true才能配合ribbon使用负载均衡 eureka.client.fetch-registry=true #集群版 eureka.client.service-url.defaultZone=http://eureka-server1.com:9090/eureka/,http://eureka-server2.com:9091/eureka/ # Eureka 客户端应用实例的ID eureka.instance.instance-id=${spring.application.name}:${server.port} #点进去左下角会显示ip eureka.instance.prefer-ip-address=true # 调整注册信息的获取周期 eureka.client.registry-fetch-interval-seconds=5 # 调整客户端应用状态信息上报的周期 eureka.client.instance-info-replication-interval-seconds=5 # seata config.type=file相关配置 seata.enabled=true seata.application-id=${spring.application.name} # 不同的微服务vgroup_mapping.seata_eureka_bank1_group配置不同 #这里的名字与file.conf中vgroup_mapping.seata_eureka_bank1_group = "seata-server"相同 seata.tx-service-group=seata_eureka_bank1_group #这里的名字与file.conf中vgroup_mapping.seata_eureka_bank1_group = "seata-server"相同 seata.service.vgroup-mapping.seata_eureka_bank1_group=seata-server #这里的名字与file.conf中default.grouplist = "127.0.0.1:8091"相同 seata.service.grouplist.default=127.0.0.1:8091 # 开启数据源自动代理 seata.enable-auto-data-source-proxy=true # 配置中心为本地file文件 seata.config.type=file # 配置中心为本地file文件的文件名称 seata.config.file.name=file.conf seata.registry.type=eureka seata.registry.eureka.application=seata-server seata.registry.eureka.serviceUrl=http://eureka-server1.com:9090/eureka/,http://eureka-server2.com:9091/eureka/ seata.registry.eureka.weight=1 mybatis.type-aliases-package=com.yibo.eureka.seata.entity mybatis.mapper-locations=classpath:mapper/*.xml mapper.identity=MYSQL mapper.not-empty=false spring.datasource.url=jdbc:mysql://localhost:3306/trade_bank1?useUnicode=true&useAffectedRows=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC spring.datasource.username=root spring.datasource.password=yibo spring.datasource.driver-class-name=com.mysql.jdbc.Driver # 设置连接超时时间 default 2000 ribbon.ConnectTimeout=6000 # 设置读取超时时间 default 5000 ribbon.ReadTimeout=6000 # 对所有操作请求都进行重试 default false ribbon.OkToRetryOnAllOperations=true # 切换实例的重试次数 default 1 ribbon.MaxAutoRetriesNextServer=2 # 对当前实例的重试次数 default 0 ribbon.MaxAutoRetries=1

3.4、启动类配置

@MapperScan("com.yibo.eureka.seata.mapper")//扫描mybatis的指定包下的接口 @SpringBootApplication @EnableDiscoveryClient //服务发现，对外暴露服务 @EnableEurekaClient //本服务启动后会自动注册进Eureka服务中 @EnableFeignClients public class EurekaSeataBank1Application { public static void main(String[] args) { SpringApplication.run(EurekaSeataBank1Application.class,args); } }

四、业务逻辑实现

4.1、Controller实现

@RestController @RequestMapping("/bank1") public class Bank1Controller { @Autowired private AccountService accountService; @GetMapping("/transfer/{amount}") public String transfer(@PathVariable("amount") Long amount){ accountService.updateAccountBalance("1",amount); return "bank1"+amount; } }

4.2、Service实现，@GlobalTransactional注解用以开启全局事务，@Transactional注解用于分支事务

@Service @Slf4j public class AccountServiceImpl implements AccountService { @Autowired private AccountInfoMapper accountInfoMapper; @Autowired private Bank2Client bank2Client; @Transactional @GlobalTransactional//开启全局事务 public void updateAccountBalance(String accountNo, Long amount) { log.info("bank1 service begin,XID：{}", RootContext.getXID()); //扣减张三的金额 accountInfoMapper.updateAccountBalance(accountNo,amount *-1); //调用李四微服务，转账 String transfer = bank2Client.transfer(amount); if("fallback".equals(transfer)){ //调用李四微服务异常 throw new RuntimeException("调用李四微服务异常"); } if(amount == 2){ //人为制造异常 throw new RuntimeException("bank1 make exception.."); } } }

4.3、Bank2Client接口的FeignClient

@FeignClient(value="eureka-seata-bank2") public interface Bank2Client { //远程调用微服务 @GetMapping("/bank2/transfer/{amount}") public String transfer(@PathVariable("amount") Long amount); }

其他微服务按此配置即可。

github源码地址：https://github.com/jjhyb/distributed-transaction