分布式事务框架 Seata 入门案例()

  本篇文章为你整理了分布式事务框架 Seata 入门案例()的详细内容,包含有 分布式事务框架 Seata 入门案例,希望能帮助你了解 分布式事务框架 Seata 入门案例。

  1. Seata Server 部署

  Seata分TC、TM和RM三个角色,TC(Server端)为单独服务端部署,TM和RM(Client端)由业务系统集成。

  首先,下载最新的安装包

  也可以下载源码,然后本地编译。最新的版本是1.5.2

  下载后的启动包(或者源码)中有个scripts目录,里面有各种我们所需的脚本

  Server端存储模式(store.mode)现有file、db、redis三种:

  file模式为单机模式,全局事务会话信息内存中读写并持久化本地文件root.data,性能较高;(不推荐)

  db模式为高可用模式,全局事务会话信息通过db共享,相应性能差些;

  redis模式Seata-Server 1.3及以上版本支持,性能较高,存在事务信息丢失风险,请提前配置合适当前场景的redis持久化配置;

  修改配置文件

  启动包:seata-- conf-- application.yml

  源码包:根目录-- seata-server-- resources-- application.yml

  主要修改的点是:

  修改store.mode="db或者redis"

  修改seata.config、seata.registry

  修改数据库连接redis属性配置

  在资源目录还有一个application.example.yml文件,application.example.yml中附带额外配置,可以将其dbredis相关配置复制至application.yml,进行修改store.db或store.redis相关属性。

  如果不使用外部配置中心,直接使用本地文件配置的话,那么最简单的配置可能是这样的:

  

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:

   type: file

   registry:

   type: nacos

   nacos:

   application: seata-server

   server-addr: 127.0.0.1:8848

   group: SEATA_GROUP

   namespace:

   cluster: default

   store:

   mode: db

   datasource: druid

   db-type: mysql

   driver-class-name: com.mysql.cj.jdbc.Driver

   url: jdbc:mysql://127.0.0.1:3306/seata?rewriteBatchedStatements=true useUnicode=true serverTimezone=Asia/Shanghai

   user: root

   password: 123456

   min-conn: 5

   max-conn: 100

   global-table: global_table

   branch-table: branch_table

   lock-table: lock_table

   distributed-lock-table: distributed_lock

   query-limit: 100

   max-wait: 5000

   security:

   secretKey: SeataSecretKey0c382ef121d778043159209298fd40bf3850a017

   tokenValidityInMilliseconds: 1800000

   ignore:

   urls: /,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*.png,/**/*.ico,/console-fe/public/**,/api/v1/auth/login

 

  更多配置请参见 https://seata.io/zh-cn/docs/user/configurations.html

  这里面哪些是Server端需要配置的,哪些是Client端需要配置的,以及每个参数的含义都解释得非常详细,强烈建议看一下,这里就不在赘述。

  此处注册中心用nacos

  https://nacos.io/zh-cn/index.html

  建表(默认数据库是seata)

  

USE `seata`;

 

  -- -------------------------------- 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 COMMENT = 全局事务表;

  -- 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 COMMENT = 分支事务表;

  -- 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_and_branch_id` (`xid` , `branch_id`)

  ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COMMENT = 全局锁表;

  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);

 

  如果采用AT模式,那么每个业务数据库还需建一个undo_log表

  

-- for AT mode you must to init this sql for you business database. the seata server not need it.

 

  CREATE TABLE IF NOT EXISTS `undo_log`

   `branch_id` BIGINT 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 AUTO_INCREMENT = 1 DEFAULT CHARSET = utf8mb4 COMMENT =AT transaction mode undo table;

 

  启动

  源码启动: 执行ServerApplication.java的main方法

  命令启动: seata-server.sh -h 127.0.0.1 -p 8091 -m db

  -h: 注册到注册中心的ip

  -p: Server rpc 监听端口

  -m: 全局事务会话信息存储模式,file、db、redis,优先读取启动参数

  -n: Server node,多个Server时,需区分各自节点,用于生成不同区间的transactionId,以免冲突

  -e: 多环境配置参考 http://seata.io/en-us/docs/ops/multi-configuration-isolation.html 

  
依赖seata-all

  依赖seata-spring-boot-starter,支持yml、properties配置(.conf可删除),内部已依赖seata-all

  依赖spring-cloud-alibaba-seata,内部集成了seata,并实现了xid传递

  步骤二:undo_log建表、配置参数(仅AT模式)

  https://seata.io/zh-cn/docs/user/configurations.html

  步骤三:数据源代理(不支持自动和手动配置并存)

  1、如果使用seata-all

  自动配置由注解@EnableAutoDataSourceProxy开启,并可选择jdk proxy或者cglib proxy。

  如果采用XA模式,@EnableAutoDataSourceProxy(dataSourceProxyMode = "XA")

  手动配置参考如下:

  

@Primary

 

  @Bean("dataSource")

  public DataSource dataSource(DataSource druidDataSource) {

   //AT 代理 二选一

   return new DataSourceProxy(druidDataSource);

   //XA 代理

   return new DataSourceProxyXA(druidDataSource)

  }

 

  2、如果使用seata-starter

  默认就开启了自动代理数据源,无需额外配置

  如果使用自动代理数据源时,如果使用XA模式还需要调整配置文件application.yml

  

seata:

 

   data-source-proxy-mode: XA

 

  如果想要关闭seata-spring-boot-starter的数据源自动代理,可调整配置文件application.yml

  

seata:

 

   enable-auto-data-source-proxy: false

 

  步骤四:初始化GlobalTransactionScanner

  自动,引入seata-spring-boot-starter、spring-cloud-starter-alibaba-seata等jar即可

  手动

  

@Bean

 

  public GlobalTransactionScanner globalTransactionScanner() {

   String applicationName = this.applicationContext.getEnvironment().getProperty("spring.application.name");

   String txServiceGroup = this.seataProperties.getTxServiceGroup();

   if (StringUtils.isEmpty(txServiceGroup)) {

   txServiceGroup = applicationName + "-fescar-service-group";

   this.seataProperties.setTxServiceGroup(txServiceGroup);

   return new GlobalTransactionScanner(applicationName, txServiceGroup);

  }

 

  步骤五:业务使用

  只需在业务方法上加上@GlobalTransactional 注解即可

  附:

  

server:

 

   port: 8104

  spring:

   application:

   name: dubbo-business-example

  #====================================Dubbo config===============================================

  dubbo:

   application:

   id: dubbo-business-example

   name: dubbo-business-example

   qosEnable: false

   protocol:

   id: dubbo

   name: dubbo

   port: 10001

   registry:

   id: dubbo-business-example-registry

   address: nacos://127.0.0.1:8848

   config-center:

   address: nacos://127.0.0.1:8848

   metadata-report:

   address: nacos://127.0.0.1:8848

  #====================================Seata Config===============================================

  seata:

   enabled: true

   application-id: business-seata-example

   tx-service-group: my_test_tx_group # 事务群组(可以每个应用独立取名,也可以使用相同的名字)

   client:

   rm-report-success-enable: true

   rm-table-meta-check-enable: false # 自动刷新缓存中的表结构(默认false)

   rm-report-retry-count: 5 # 一阶段结果上报TC重试次数(默认5)

   rm-async-commit-buffer-limit: 10000 # 异步提交缓存队列长度(默认10000)

   lock:

   lock-retry-internal: 10 # 校验或占用全局锁重试间隔(默认10ms)

   lock-retry-times: 30 # 校验或占用全局锁重试次数(默认30)

   lock-retry-policy-branch-rollback-on-conflict: true # 分支事务与其它全局回滚事务冲突时锁策略(优先释放本地锁让回滚成功)

   tm-commit-retry-count: 3 # 一阶段全局提交结果上报TC重试次数(默认1次,建议大于1)

   tm-rollback-retry-count: 3 # 一阶段全局回滚结果上报TC重试次数(默认1次,建议大于1)

   undo:

   undo-data-validation: true # 二阶段回滚镜像校验(默认true开启)

   undo-log-serialization: jackson # undo序列化方式(默认jackson)

   undo-log-table: undo_log # 自定义undo表名(默认undo_log)

   log:

   exceptionRate: 100 # 日志异常输出概率(默认100)

   support:

   spring:

   datasource-autoproxy: true

   service:

   vgroup-mapping:

   my_test_tx_group: default # TC 集群(必须与seata-server保持一致)

   enable-degrade: false # 降级开关

   disable-global-transaction: false # 禁用全局事务(默认false)

   grouplist:

   default: 127.0.0.1:8091

   transport:

   shutdown:

   wait: 3

   thread-factory:

   boss-thread-prefix: NettyBoss

   worker-thread-prefix: NettyServerNIOWorker

   server-executor-thread-prefix: NettyServerBizHandler

   share-boss-worker: false

   client-selector-thread-prefix: NettyClientSelector

   client-selector-thread-size: 1

   client-worker-thread-prefix: NettyClientWorkerThread

   type: TCP

   server: NIO

   heartbeat: true

   serialization: seata

   compressor: none

   enable-client-batch-send-request: true # 客户端事务消息请求是否批量合并发送(默认true)

   registry:

   file:

   name: file.conf

   type: nacos

   nacos:

   server-addr: localhost:8848

   namespace:

   cluster: default

   group: SEATA_GROUP

   username: nacos

   password: nacos

   config:

   file:

   name: file.conf

   type: nacos

   nacos:

   namespace:

   server-addr: localhost:8848

   group: SEATA_GROUP

   username: nacos

   password: nacos

   dataId: nacos-server.properties

 

  3. 示例代码

  此处用官网的那个案例,调用关系如图:

  首先,建库建表,脚本如下:

  SQL脚本

  

CREATE DATABASE `account`;

 

  USE `account`;

  DROP TABLE IF EXISTS `t_account`;

  CREATE TABLE `t_account` (

   `id` int NOT NULL AUTO_INCREMENT,

   `user_id` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,

   `amount` double(14,2) DEFAULT 0.00,

   PRIMARY KEY (`id`)

  ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

  INSERT INTO `t_account` VALUES (1,1,79.90);

  DROP TABLE IF EXISTS `undo_log`;

  CREATE TABLE `undo_log` (

   `branch_id` bigint 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 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=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT=AT transaction mode undo table;

  
`id` int NOT NULL AUTO_INCREMENT,

   `order_no` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,

   `user_id` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,

   `commodity_code` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,

   `count` int DEFAULT 0,

   `amount` double(14,2) DEFAULT 0.00,

   PRIMARY KEY (`id`)

  ) ENGINE=InnoDB AUTO_INCREMENT=21 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

  DROP TABLE IF EXISTS `undo_log`;

  CREATE TABLE `undo_log` (

   `branch_id` bigint 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 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=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT=AT transaction mode undo table;

  
`id` int NOT NULL AUTO_INCREMENT,

   `commodity_code` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,

   `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,

   `count` int DEFAULT 0,

   PRIMARY KEY (`id`),

   UNIQUE KEY `commodity_code` (`commodity_code`)

  ) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

  INSERT INTO `t_stock` VALUES (1,A001,立白洗洁精,7);

  DROP TABLE IF EXISTS `undo_log`;

  CREATE TABLE `undo_log` (

   `branch_id` bigint 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 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=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT=AT transaction mode undo table;

 

  注意版本:示例中使用的框架为 Spring Boot + Mybatis-Plus + Dubbo + Seata

  虽然Seata最新版本是1.5.2,Dubbo最新版本为3.1.1,但这这两个版本中二者不兼容,可以降低其中一个的版本,比如

  Seata 1.4.2 + Dubbo 3.1.1 或者 Seata 1.5.2 + Dubbo 2.7.18

  本示例中采用的是 seata-spring-boot-starter 1.5.2 + dubbo 2.7.18

  工程结构如图

  父pom.xml如下

  

 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

   groupId com.cjs.example /groupId

   artifactId seata-spring-boot-starter-samples /artifactId

   version 1.0-SNAPSHOT /version

   packaging pom /packaging

   name seata-spring-boot-starter-samples /name

   modules

   module samples-common-service /module

   module samples-stock-service /module

   module samples-order-service /module

   module samples-account-service /module

   module samples-business-service /module

   /modules

   properties

   project.build.sourceEncoding UTF-8 /project.build.sourceEncoding

   spring-boot.version 2.7.5 /spring-boot.version

   dubbo.version 2.7.18 /dubbo.version

   seata.version 1.5.2 /seata.version

   mybatis-plus.version 3.5.2 /mybatis-plus.version

   /properties

   dependencies

   dependency

   groupId org.springframework.boot /groupId

   artifactId spring-boot-starter-web /artifactId

   /dependency

   dependency

   groupId org.projectlombok /groupId

   artifactId lombok /artifactId

   optional true /optional

   /dependency

   /dependencies

   dependencyManagement

   dependencies

   dependency

   groupId org.springframework.boot /groupId

   artifactId spring-boot-dependencies /artifactId

   version ${spring-boot.version} /version

   type pom /type

   scope import /scope

   /dependency

   dependency

   groupId org.apache.dubbo /groupId

   artifactId dubbo-dependencies-bom /artifactId

   version ${dubbo.version} /version

   type pom /type

   scope import /scope

   /dependency

   dependency

   groupId org.apache.dubbo /groupId

   artifactId dubbo /artifactId

   version ${dubbo.version} /version

   /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-registry-nacos /artifactId

   version ${dubbo.version} /version

   /dependency

   dependency

   groupId io.seata /groupId

   artifactId seata-spring-boot-starter /artifactId

   version ${seata.version} /version

   /dependency

   dependency

   groupId com.baomidou /groupId

   artifactId mybatis-plus-boot-starter /artifactId

   version ${mybatis-plus.version} /version

   /dependency

   /dependencies

   /dependencyManagement

   /project

 

  子pom.xml如下,其它几个类似不再重复:

  

 ?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 com.cjs.example /groupId

   artifactId seata-spring-boot-starter-samples /artifactId

   version 1.0-SNAPSHOT /version

   /parent

   groupId com.cjs.example /groupId

   artifactId samples-order-service /artifactId

   version ${parent.version} /version

   name samples-order-service /name

   properties

   java.version 1.8 /java.version

   /properties

   dependencies

   dependency

   groupId com.cjs.example /groupId

   artifactId samples-common-service /artifactId

   version ${parent.version} /version

   /dependency

   dependency

   groupId org.apache.dubbo /groupId

   artifactId dubbo /artifactId

   /dependency

   dependency

   groupId org.apache.dubbo /groupId

   artifactId dubbo-spring-boot-starter /artifactId

   /dependency

   dependency

   groupId org.apache.dubbo /groupId

   artifactId dubbo-registry-nacos /artifactId

   /dependency

   dependency

   groupId io.seata /groupId

   artifactId seata-spring-boot-starter /artifactId

   /dependency

   dependency

   groupId com.baomidou /groupId

   artifactId mybatis-plus-boot-starter /artifactId

   /dependency

   dependency

   groupId mysql /groupId

   artifactId mysql-connector-java /artifactId

   scope runtime /scope

   /dependency

   dependency

   groupId org.springframework.boot /groupId

   artifactId spring-boot-starter-test /artifactId

   scope test /scope

   /dependency

   /dependencies

   build

   plugins

   plugin

   groupId org.springframework.boot /groupId

   artifactId spring-boot-maven-plugin /artifactId

   /plugin

   /plugins

   /build

   /project

 

  application.yml

  

server:

 

   port: 8083

   servlet:

   context-path: /order

  spring:

   application:

   name: samples-order-service

   datasource:

   driver-class-name: com.mysql.cj.jdbc.Driver

   url: jdbc:mysql://127.0.0.1:3306/order?useSSL=false useUnicode=true characterEncoding=utf-8 serverTimezone=Asia/Shanghai

   username: root

   password: 123456

  dubbo:

   protocol:

   name: dubbo

   port: 20883

   registry:

   address: nacos://127.0.0.1:8848

   config-center:

   address: nacos://127.0.0.1:8848

   metadata-report:

   address: nacos://127.0.0.1:8848

  seata:

   enabled: true

   tx-service-group: my_test_tx_group

   service:

   vgroup-mapping:

   my_test_tx_group: default

   registry:

   type: nacos

   nacos:

   server-addr: 127.0.0.1:8848

   cluster: default

   group: SEATA_GROUP

 

  核心代码如下

  依次启动这四个项目,Postman访问一下

  通过断点,观察 global_table、lock_table、branch_table 等表数据的变化

  刚开始,所有表中数据都是空的

  执行到事务方法之后,global_table表中有了一条数据

  当调用第一个远程接口扣减库存后,lock_table和branch_table表中都有了一条数据

  同时,stock库中undo_log表中也新增了一条数据

  继续往下执行,当调用第二个远程接口创建订单后,branch_table和lock_table中都新增了2条数据

  account库和order库中的undo_log也有了数据

  当事务方法执行完后,事务提交,上述表中此次事务相关数据清空

  我们通过Seata Server的日志可以更清晰的看到事务从创建到提交的整个过程

  正式正常事务成功的情况,有时候由于业务报错了,或者事务超时了,或者其它的情况,事务会回滚

  4. 配置中心

  在此之前,示例中没有使用配置中心,而是采用本地配置文件的方式。但实际开发过程中,建议还是采用配置中心,下面以nacos作为配置中心演示。

  细心的同学会发现,微服务架构中有配置中心和注册中心,Dubbo中也有配置中心和注册中心,而本文讲的Seata也有配置中心和注册中心。那么它们有什么区别吗?其实,并没有区别,各是各的。微服务的配置中心和注册中心你要配置,Dubbo的你也要配置,Seata的配置中心和注册中心你还要配置,尽管它们可能是同一个实例,但那也得各配各的。

  

 dependency 

 

   groupId com.alibaba.nacos /groupId

   artifactId nacos-client /artifactId

   version 2.1.1 /version

   /dependency

 

  有两种配置方式

  方式一:放在某个命名空间下,每一个配置项作为一行,即每一行一个DataId

  https://github.com/seata/seata/tree/master/script/config-center

  在scripts/config-center目录下有个config.txt,这个config.txt文件中为我们准备好了各种配置项,我们按需修改里面的内容即可,然后可以通过脚本将config.txt中的内容导入nacos,当然也可以一条一条手动在nacos中创建

  例如:

  

sh ${SEATAPATH}/script/config-center/nacos/nacos-config.sh -h localhost -p 8848 -g SEATA_GROUP -t 5a3c7d6c-f497-4d68-a71a-2e5e3340b3ca -u username -w password

 

  注意:-g 指定Group  -t 指定命名空间

  示例中上传到默认命名空间下了

  注意,config.txt中包含了Server端和Client端的配置,里面注释写的也比较清楚哪些是Server端需要的配置,哪些是Client端的配置

  导入配置以后,现在修改Server端的配置,seata-- conf-- application.yml中seata.config部分

  

seata:

 

   config:

   type: nacos

   nacos:

   server-addr: 127.0.0.1:8848

   group : "SEATA_GROUP"

   namespace:

   username:

   password:

 

  同时,每个业务系统里面的配置也要修改一下

  

seata:

 

   config:

   type: nacos

   nacos:

   server-addr: 127.0.0.1:8848

   group : "SEATA_GROUP"

   namespace:

   username:

   password:

 

  由于这里导入配置的时候没有-t指定命名空间,即导入到默认命名空间,所以配置里面namespace为空,如果-t指定了特定的命名空间,则server和client端的namespace也要与之对应

  方式二:通过dataId配置

  首先,需要在nacos新建配置,此处dataId为seataServer.properties

  然后,将修改后的config.txt内容粘贴进去,保存修改并发布即可

  修改Server和Client端seata.config配置

  

seata:

 

   config:

   type: nacos

   nacos:

   server-addr: 127.0.0.1:8848

   group: "SEATA_GROUP"

   namespace:

   dataId: "seataServer.properties"

   username:

   password:

 

  重启Server和Client即可

  代码地址:https://gitee.com/chengjiansheng/seata-spring-boot-starter-sampless

  以上就是分布式事务框架 Seata 入门案例()的详细内容,想要了解更多 分布式事务框架 Seata 入门案例的内容,请持续关注盛行IT软件开发工作室。

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