Seata的集成方式有：
1. Seata-All
2. Seata-Spring-Boot-Starter
3. Spring-Cloud-Starter-Seata
本案例使用Seata-All演示：
第一步：下载Seata
第二步：为了更好看到效果，我们将Seata的数据存储改为db
将seata\script\server\db\mysql.sql语句在mysql中执行，创建相关表
然后修改seata配置文件，相关配置可以参考application.example.yml，此处修改mode为db并且配置db相关配置
启动seata：
第三步：开始集成Seata
1.在我们的项目pom.xml引入seata包（1.5.x有bug，我们使用1.4.2）
<!--seata-->
<dependency>
<groupId>io.seata</groupId>
<artifactId>seata-all</artifactId>
</dependency>
<dependency>
<groupId>com.esotericsoftware</groupId>
<artifactId>kryo</artifactId>
</dependency>
<dependency>
<groupId>de.javakaffee</groupId>
<artifactId>kryo-serializers</artifactId>
</dependency>2.application.properties
#环境配置
spring.profiles.active=dev
spring.application.name=user-service-provider
dubbo.application.id=user-service
dubbo.application.name=user-service
#dubbo.protocol.port=-1
#dubbo.protocol.name=dubbo
#多协议支持
dubbo.protocols.tri.name=tri
dubbo.protocols.tri.port=-1
dubbo.protocols.tri.id=tri
dubbo.protocols.dubbo.name=dubbo
dubbo.protocols.dubbo.port=-1
dubbo.protocols.dubbo.id=dubbo
#序列化方式
dubbo.protocols.dubbo.serialization=kryo
dubbo.application.logger=log4j
#调用信息跟踪-log4j 日志
#dubbo.protocol.accesslog=true
#调用信息跟踪-将访问日志输出到指定文件
#dubbo.protocol.accesslog=/log/access.log
#是否简化 url
#dubbo.registry.simplified=true
#dubbo.registry.id=zk-registry
#dubbo.registry.address=zookeeper://192.168.1.105:2181?timeout=20000
#dubbo.config-center.address=zookeeper://192.168.1.105:2181?timeout=20000
#dubbo.metadata-report.address=zookeeper://192.168.1.105:2181?timeout=20000
#多注册中心
#dubbo.registries.zk-registry.id=zk-registry
#dubbo.registries.zk-registry.address=zookeeper://192.168.1.105:2181?timeout=20000&blockUntilConnectedWait=30
dubbo.registries.nacos-registry.id=nacos-registry
dubbo.registries.nacos-registry.address=nacos://192.168.1.105:8848
#dubbo.registries.nacos-registry.address=nacos://192.168.1.105:8848?namespace=2e73933a-34d4-4fba-b21e-f08cd9b8adc9
dubbo.registry.use-as-config-center=false
dubbo.registry.use-as-metadata-center=false
#nacos配置中心
nacos.config.server-addr=192.168.1.105:8848
#mybatis
mybatis.mapper-locations= classpath*:com/lee/demo/dubbo/demo/dao/*Mapper.xml
mybatis.type-aliases-package=com.lee.demo.dubbo.demo.entity
#datasource
spring.datasource.url=jdbc:mysql://localhost:3308/coupon-platform?useUnicode=true&characterEncoding=utf8&useOldAliasMetadataBehavior=true&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=Aa1225102411
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
3.在resources目录下添加配置文件file.conf和registry.conf，seata会扫描这两个配置文件从而获取相关配置。
registry.conf：
registry {
# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
type = "file"
file {
name = "file.conf"
}
}
config {
# file、nacos 、apollo、zk、consul、etcd3
type = "file"
file {
name = "file.conf"
}
}
file.conf：
transport {
# tcp, unix-domain-socket
type = "TCP"
#NIO, NATIVE
server = "NIO"
#enable heartbeat
heartbeat = true
# the tm client batch send request enable
enableTmClientBatchSendRequest = false
# the rm client batch send request enable
enableRmClientBatchSendRequest = true
# the rm client rpc request timeout
rpcRmRequestTimeout = 2000
# the tm client rpc request timeout
rpcTmRequestTimeout = 10000
# the tc client rpc request timeout
rpcTcRequestTimeout = 5000
#thread factory for netty
threadFactory {
bossThreadPrefix = "NettyBoss"
workerThreadPrefix = "NettyServerNIOWorker"
serverExecutorThread-prefix = "NettyServerBizHandler"
shareBossWorker = false
clientSelectorThreadPrefix = "NettyClientSelector"
clientSelectorThreadSize = 1
clientWorkerThreadPrefix = "NettyClientWorkerThread"
# netty boss thread size
bossThreadSize = 1
#auto default pin or 8
workerThreadSize = "default"
}
shutdown {
# when destroy server, wait seconds
wait = 3
}
serialization = "seata"
compressor = "none"
}
service {
#transaction service group mapping
vgroupMapping.demo-tx-default-group = "default"
#only support when registry.type=file, please don't set multiple addresses
default.grouplist = "192.168.8.133:8091"
#degrade, current not support
enableDegrade = false
#disable seata
disableGlobalTransaction = false
}
client {
rm {
asyncCommitBufferLimit = 10000
lock {
retryInterval = 10
retryTimes = 30
retryPolicyBranchRollbackOnConflict = true
}
reportRetryCount = 5
tableMetaCheckEnable = false
tableMetaCheckerInterval = 60000
reportSuccessEnable = false
sagaBranchRegisterEnable = false
sagaJsonParser = "fastjson"
sagaRetryPersistModeUpdate = false
sagaCompensatePersistModeUpdate = false
tccActionInterceptorOrder = -2147482648 #Ordered.HIGHEST_PRECEDENCE + 1000
}
tm {
commitRetryCount = 5
rollbackRetryCount = 5
defaultGlobalTransactionTimeout = 60000
degradeCheck = false
degradeCheckPeriod = 2000
degradeCheckAllowTimes = 10
interceptorOrder = -2147482648 #Ordered.HIGHEST_PRECEDENCE + 1000
}
undo {
dataValidation = true
onlyCareUpdateColumns = true
logSerialization = "kryo"
logTable = "undo_log"
compress {
enable = true
# allow zip, gzip, deflater, 7z, lz4, bzip2, zstd default is zip
type = zip
# if rollback info size > threshold, then will be compress
# allow k m g t
threshold = 64k
}
}
loadBalance {
type = "RandomLoadBalance"
virtualNodes = 10
}
}
log {
exceptionRate = 100
}
tcc {
fence {
# tcc fence log table name
logTableName = tcc_fence_log
# tcc fence log clean period
cleanPeriod = 1h
}
}4.编写Seata全局事务扫描器配置类SeataTransctionConfig：
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import io.seata.spring.annotation.GlobalTransactionScanner;
@Configuration
public class SeataTransctionConfig {
@Bean
public GlobalTransactionScanner globalTransactionScanner() {
String txServiceGroup = "demo-tx-default-group";
return new GlobalTransactionScanner(txServiceGroup);
}
}
注意：在file.conf中的service配置要和SeataTransctionConfig 中指定的txServiceGroup 一致
5. 由于AT模型是使用本地undo_log进行回滚，因此，我们每个事务所在的数据库中需要添加该表
在seata github中有样板，链接：https://github.com/seata/seata/tree/develop/srcipt/client/at/db
其中mysql.sql如下：
-- ----------------------------
-- Table structure for undo_log
-- ----------------------------
DROP TABLE IF EXISTS `undo_log`;
CREATE TABLE `undo_log` (
`branch_id` bigint NOT NULL COMMENT 'branch transaction id',
`xid` varchar(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT 'global transaction id',
`context` varchar(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci 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 INDEX `ux_undo_log`(`xid`, `branch_id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 1 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci COMMENT = 'AT transaction mode undo table' ROW_FORMAT = Dynamic;
-- ----------------------------
-- Records of undo_log
-- ---------------------------- 
测试：
在抛异常之前打断点，查看数据是否成功插入过：
看到记录插入成功，并且undo_log中记录了这两个事务的日志：
断点继续往下走，触发异常，，已插入的数据被回滚，且undo_log被清空，分布式事务回滚正常。
至此，Spring集成Seata演示完毕
