(一) seata 介绍

• Seata 是一款阿里开源的分布式事务解决方案，致力于提供高性能和简单易用的分布式事务服务。Seata 将为用户提供了 AT、TCC、SAGA 和 XA 事务模式，为用户打造一站式的分布式解决方案
• 这里演示学习使用SpringCloud/SpringBoot集成配置了Seata，并使用AT模式实现分布式事务回滚
• Seata GitHub
• Seata 官方文档
• Seata Demo GitHub

(二) Seata server 安装配置

环境准备

• Mac OS
• Mysql8
• Eureka注册中心

GitHub 下载v1.1.0 Seata v1.1.0

• unzip seata-server-1.1.0.zip
• cd /seata/conf
• 由于seatev1.1.0默认驱动是mysql5,在seata/lib目录下，将mysql-connector-java-8.0.19.jar版本的jar包替换原来的mysq5;修改file.conf中的driverClassName = “com.mysql.cj.jdbc.Driver”
• 修改file.conf如下；修改为db模式，并且配置自己的mysql数据库链接；注意service配置中的vgroupMapping.licaibo_tx_group，其中licaibo_tx_group为自己定义，到时SpringBoot集成seata的时候需要保持一致

## transaction log store, only used in seata-server
store {## store mode: file、dbmode = "db"## file store propertyfile {## store location dirdir = "sessionStore"# branch session size , if exceeded first try compress lockkey, still exceeded throws exceptionsmaxBranchSessionSize = 16384# globe session size , if exceeded throws exceptionsmaxGlobalSessionSize = 512# file buffer size , if exceeded allocate new bufferfileWriteBufferCacheSize = 16384# when recover batch read sizesessionReloadReadSize = 100# async, syncflushDiskMode = async}## database store propertydb {## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp) etc.datasource = "dbcp"## mysql/oracle/h2/oceanbase etc.dbType = "mysql"driverClassName = "com.mysql.cj.jdbc.Driver"url = "jdbc:mysql://localhost:3306/seat-server"user = "root"password = "root"minConn = 1maxConn = 10globalTable = "global_table"branchTable = "branch_table"lockTable = "lock_table"queryLimit = 100}service {#transaction service group mappingvgroupMapping.licaibo_tx_group = "default"#only support when registry.type=file, please don't set multiple addressesdefault.grouplist = "127.0.0.1:8091"#degrade, current not supportenableDegrade = false#disable seatadisableGlobalTransaction = false
}}

在自己的seat-server数据库需要创建三张表，具体脚本在 Seata-mysql-script

-- -------------------------------- 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 = InnoDBDEFAULT 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(6),`gmt_modified`      DATETIME(6),PRIMARY KEY (`branch_id`),KEY `idx_xid` (`xid`)
) ENGINE = InnoDBDEFAULT 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 = InnoDBDEFAULT CHARSET = utf8;

修改registry.conf,配置注册的Eureka注册中心

registry {# file 、nacos 、eureka、redis、zk、consul、etcd3、sofatype = "eureka"nacos {serverAddr = "localhost"namespace = ""cluster = "default"}eureka {serviceUrl = "http://localhost:9001/eureka"application = "default"weight = "1"}redis {serverAddr = "localhost:6379"db = "0"}zk {cluster = "default"serverAddr = "127.0.0.1:2181"session.timeout = 6000connect.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、etcd3type = "file"nacos {serverAddr = "localhost"namespace = ""group = "SEATA_GROUP"}consul {serverAddr = "127.0.0.1:8500"}apollo {app.id = "seata-server"apollo.meta = "http://192.168.1.204:8801"namespace = "application"}zk {serverAddr = "127.0.0.1:2181"session.timeout = 6000connect.timeout = 2000}etcd3 {serverAddr = "http://localhost:2379"}file {name = "file.conf"}
}

(三) SpringBoot/SpringClod集成Seata

在各个微服务的SpringBoot增加依赖

        com.alibaba.cloudspring-cloud-alibaba-seata2.1.0.RELEASEseata-allio.seataio.seataseata-all1.1.0

在每个微服务的数据库创建undo_log,用于执行回滚记录;具体脚本在 Seata-mysql-script

-- 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`
(`id`            BIGINT(20)   NOT NULL AUTO_INCREMENT COMMENT 'increment id',`branch_id`     BIGINT(20)   NOT NULL COMMENT 'branch transaction id',`xid`           VARCHAR(100) 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     NOT NULL COMMENT 'create datetime',`log_modified`  DATETIME     NOT NULL COMMENT 'modify datetime',PRIMARY KEY (`id`),UNIQUE KEY `ux_undo_log` (`xid`, `branch_id`)
) ENGINE = InnoDBAUTO_INCREMENT = 1DEFAULT CHARSET = utf8 COMMENT ='AT transaction mode undo table';

resources目录下增加file.conf和registry.conf两个配置文件

• SpringBoot配置file.conf；注意service中的vgroupMapping.licaibo_tx_group，其中licaibo_tx_group和seata server的配置保持一致

           transport {# tcp udt unix-domain-sockettype = "TCP"#NIO NATIVEserver = "NIO"#enable heartbeatheartbeat = true# the client batch send request enableenableClientBatchSendRequest = true#thread factory for nettythreadFactory {bossThreadPrefix = "NettyBoss"workerThreadPrefix = "NettyServerNIOWorker"serverExecutorThread-prefix = "NettyServerBizHandler"shareBossWorker = falseclientSelectorThreadPrefix = "NettyClientSelector"clientSelectorThreadSize = 1clientWorkerThreadPrefix = "NettyClientWorkerThread"# netty boss thread size,will not be used for UDTbossThreadSize = 1#auto default pin or 8workerThreadSize = "default"}shutdown {# when destroy server, wait secondswait = 3}serialization = "seata"compressor = "none"}service {#transaction service group mappingvgroupMapping.licaibo_tx_group = "default"#only support when registry.type=file, please don't set multiple addressesdefault.grouplist = "127.0.0.1:8091"#degrade, current not supportenableDegrade = false#disable seatadisableGlobalTransaction = false}client {rm {asyncCommitBufferLimit = 10000lock {retryInterval = 10retryTimes = 30retryPolicyBranchRollbackOnConflict = true}reportRetryCount = 5tableMetaCheckEnable = falsereportSuccessEnable = false}tm {commitRetryCount = 5rollbackRetryCount = 5}undo {dataValidation = truelogSerialization = "jackson"logTable = "undo_log"}log {exceptionRate = 100}}

SpringBoot配置registry.conf

      registry {# file 、nacos 、eureka、redis、zk、consul、etcd3、sofatype = "eureka"nacos {serverAddr = "localhost"namespace = ""cluster = "default"}eureka {serviceUrl = "http://localhost:9001/eureka"application = "default"weight = "1"}redis {serverAddr = "localhost:6379"db = "0"}zk {cluster = "default"serverAddr = "127.0.0.1:2181"session.timeout = 6000connect.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、etcd3type = "file"nacos {serverAddr = "localhost"namespace = ""group = "SEATA_GROUP"}consul {serverAddr = "127.0.0.1:8500"}apollo {app.id = "seata-server"apollo.meta = "http://192.168.1.204:8801"namespace = "application"}zk {serverAddr = "127.0.0.1:2181"session.timeout = 6000connect.timeout = 2000}etcd3 {serverAddr = "http://localhost:2379"}file {name = "file.conf"}}

配置SpringBoot工程的application.yml

spring:cloud:alibaba:seata:tx-service-group: licaibo_tx_group    

创建数据源代理

/*** 数据源代理* @author wangzhongxiang*/
@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);}@Beanpublic SqlSessionFactory sqlSessionFactory(DataSourceProxy dataSourceProxy)throws Exception{SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();sqlSessionFactoryBean.setDataSource(dataSourceProxy);sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:/mapper/*.xml"));sqlSessionFactoryBean.setTransactionFactory(new SpringManagedTransactionFactory());return sqlSessionFactoryBean.getObject();}}  

(四) 启动测试

• 启动Eureka注册中心
• 启动seata ./seata-server.sh
• 启动集成好的参与分布式事务的SpringBoot工程
• 在服务的入口使用@GlobalTransactional(name = “xxx”,rollbackFor = Exception.class)开启分布式事务
• 本文是参考阿里的demo,这里使用的是 springcloud-eureka-feign-mybatis-seata

(五) 更多集成方式例子

• seata v1.1.0提供了seata-spring-boot-starte，是使用springboot自动装配来简化seata-all的复杂配置。1.0.0可用于替换seata-all
• 配置上则不需要registry.conf和file.conf文件，将配置信息写在application.yml
• 具体参考阿里demo seata-spring-boot-starter-samples