SEATA 分布式事务入门DEMO

Simple Extensible Autonomous Transacation Architecture，seata是简单的、可扩展、自主性高的分布式架构

SEATA Server Configure

因我们使用正式的1.0.0-GA 版本，网上大多数找到的说明都是0.X版本，有不少变动，比如，在server中取消了db_store.sql的脚本，如找不到相关内容，可以通过源码来查找，比如db脚本源码：mysql db script

1. 下载 seata-server
2. 创建数据库（seata）,可自定义，在file.conf中要用到。 -- -------------------------------- 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_gmt_modified_status` (`gmt_modified`, `status`), KEY `idx_transaction_id` (`transaction_id`) ) ENGINE = InnoDB DEFAULT CHARSET = utf8; -- 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, `gmt_modified` DATETIME, PRIMARY KEY (`branch_id`), KEY `idx_xid` (`xid`) ) ENGINE = InnoDB DEFAULT CHARSET = utf8; -- the table to store lock data CREATE TABLE IF NOT EXISTS `lock_table` ( `row_key` VARCHAR(128) NOT NULL, `xid` VARCHAR(96), `transaction_id` BIGINT, `branch_id` BIGINT NOT NULL, `resource_id` VARCHAR(256), `table_name` VARCHAR(32), `pk` VARCHAR(36), `gmt_create` DATETIME, `gmt_modified` DATETIME, PRIMARY KEY (`row_key`), KEY `idx_branch_id` (`branch_id`) ) ENGINE = InnoDB DEFAULT CHARSET = utf8;
3. 编辑file.conf配置文件 service { #transaction service group mapping vgroup_mapping.sunrise_tx_group = "default" #only support when registry.type=file, please don't set multiple addresses default.grouplist = "127.0.0.1:8091" #disable seata disableGlobalTransaction = false #degrade current not support enableDegrade = false #disable disable = false #unit ms,s,m,h,d represents milliseconds, seconds, minutes, hours, days, default permanent max.commit.retry.timeout = "-1" max.rollback.retry.timeout = "-1" } ## transaction log store, only used in seata-server store { ## store mode: file、db mode = "db" ## file store property file { ## store location dir dir = "sessionStore" #degrade current not support enableDegrade = false #disable disable = false #unit ms,s,m,h,d represents milliseconds, seconds, minutes, hours, days, default permanent max.commit.retry.timeout = "-1" max.rollback.retry.timeout = "-1" } ## transaction log store, only used in seata-server store { ## store mode: file、db mode = "db" ## file store property file { ## store location dir dir = "sessionStore" } ## database store property db { ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp) etc. datasource = "dbcp" ## mysql/oracle/h2/oceanbase etc. db-type = "mysql" driver-class-name = "com.mysql.jdbc.Driver" url = "jdbc:mysql://localhost:3306/seata" user = "wr" password = "wr" min-conn = 1 max-conn = 3 global.table = "global_table" branch.table = "branch_table" lock-table = "lock_table" query-limit = 100 } }
4. 编辑conf/regiester.conf registry { # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa # 更改1 type = "eureka" nacos { serverAddr = "localhost" namespace = "" cluster = "default" } eureka { # 更改2 serviceUrl = "http://localhost:21001/eureka" application = "default" weight = "1" } redis { serverAddr = "localhost:6379" db = "0" } zk { cluster = "default" serverAddr = "127.0.0.1:2181" session.timeout = 6000 connect.timeout = 2000 } 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 = "localhost" namespace = "" } consul { serverAddr = "127.0.0.1:8500" } apollo { app.id = "seata-server" apollo.meta = "http://192.168.1.204:8801" } zk { serverAddr = "127.0.0.1:2181" session.timeout = 6000 connect.timeout = 2000 } etcd3 { serverAddr = "http://localhost:2379" } file { name = "file.conf" } } 本次实现，我们还没有添加configration的时候，因此只需要更改register块中的相关属性即可，在后续我们实现了nacos config之后，再同步更新这里。
5. 启动服务端 [root@localhost.localdomain /usr/local/geekplus/server/seata]# bin/seata-server.sh

eureka ha

在eureka中看到如下8091端口的服务之后，即启动seata-server正常！

Client Configure

AT Model

需要在每一个业务库中添加数据表undo_log.

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;

Broadway-Demo

使用Springboot项目有一个小规律，我叫它为使用三部曲。 依broadway-ws-tally-service项目为例：

• 第一步：加依赖 <!--seata--> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-alibaba-seata</artifactId> <version>2.1.0.RELEASE</version> <exclusions> <exclusion> <artifactId>seata-all</artifactId> <groupId>io.seata</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>io.seata</groupId> <artifactId>seata-all</artifactId> <version>1.0.0</version> </dependency>
• 第二步：开启注解 @SpringBootApplication(exclude = DataSourceAutoConfiguration.class) 在这里需要说明一下，我们需要排除掉SpringBoot默认自动注入的DataSourceAutoConfigurationBean, 因为SEATA是基于数据源拦截来实现的分布式事务，因此，我们需要自定义数据源配置信息： package com.geekplus.broadway.ws.tally.application; import com.alibaba.druid.pool.DruidDataSource; import io.seata.rm.datasource.DataSourceProxy; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.transaction.SpringManagedTransactionFactory; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Primary; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import javax.sql.DataSource; @Configuration public class DataSourceConfiguration { @Bean @ConfigurationProperties(prefix = "spring.datasource") public DataSource druidDataSource(){ DruidDataSource druidDataSource = new DruidDataSource(); return druidDataSource; } @Primary @Bean("dataSource") public DataSourceProxy dataSource(DataSource druidDataSource){ return new DataSourceProxy(druidDataSource); } @Bean public SqlSessionFactory sqlSessionFactory(DataSourceProxy dataSourceProxy)throws Exception{ SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean(); sqlSessionFactoryBean.setDataSource(dataSourceProxy); sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver() .getResources("classpath*:/com/geekplus/*.xml")); sqlSessionFactoryBean.setTransactionFactory(new SpringManagedTransactionFactory()); return sqlSessionFactoryBean.getObject(); } } 该配置类，一般放在与启动类相同的目录即可！
• 第三部：改配置 spring: cloud: alibaba: seata: tx-service-group: sunrise_tx_group TIPS: tx-service-group 一定要server，client都要保持一致，否则能坑死你！ tx-service-group 一定要server，client都要保持一致，否则能坑死你！ tx-service-group 一定要server，client都要保持一致，否则能坑死你！

以上三步是大多数SpringBoot 项目的通用做法，当然我们的SEATA暂时还不是那么完善，配置信息目前还不支持在application.yml中配置完全，因此，我们需要2个核心的client 配置文件file.conf和register.conf.

• file.conf 该文件主要是用于连接RM的，我们只需要关注上面所说的tx-service-group就行，其他配置默认就可以。 transport { # tcp udt unix-domain-socket type = "TCP" #NIO NATIVE server = "NIO" #enable heartbeat heartbeat = true # the client batch send request enable enable-client-batch-send-request = true #thread factory for netty 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" # netty boss thread size,will not be used for UDT boss-thread-size = 1 #auto default pin or 8 worker-thread-size = 8 } shutdown { # when destroy server, wait seconds wait = 3 } serialization = "seata" compressor = "none" } service { #transaction service group mapping vgroup_mapping.sunrise_tx_group = "default" #only support when registry.type=file, please don't set multiple addresses default.grouplist = "127.0.0.1:8091" #disable seata disableGlobalTransaction = false } client { rm { async.commit.buffer.limit = 10000 lock { retry.internal = 10 retry.times = 30 retry.policy.branch-rollback-on-conflict = true } report.retry.count = 5 table.meta.check.enable = false report.success.enable = true } tm { commit.retry.count = 5 rollback.retry.count = 5 } undo { data.validation = true log.serialization = "jackson" log.table = "undo_log" } log { exceptionRate = 100 } support { # auto proxy the DataSource bean spring.datasource.autoproxy = false } }
• register.conf该文件是用于指定注册中心相关配置的，它有2个核心block：
  • registry块 此模板表明我们的注册中心使用类型，需要根据type设置来同步更新使用的配置信息，比如我们使用的eureka，因此我们更新eureka.serviceUrl="http://172.16.1.187:21001/eureka".
  • config 块 该模块用来设置我们的配置中心相关配置（此处后续更新，我们会选择apollo）