承接上文《从0到1 手把手搭建spring cloud alibaba 微服务大型应用框架（五） SEATA分布式事务篇（中）shardingshere 多库读写分离/分库分表下分布式事务完整代码及案例》
上文中没有集成seata的情况下，跑了正常扣除库存以及生成订单的情况，下面我们来模拟上图中扣除库存成功，但是生成订单的情况，由于没有集成分布式事务，所以理论的结果肯定是库存少了，但是订单没有生成
还是使用上文中写好的业务代码，不过这次在生成订单的时候手动抛出异常，代码如下
首先清空订单数据库和还原一下库存数据库，给商品id是1的商品初始化10 个数量
然后postman 执行该接口
查看执行结果
库存服务正常
订单服务报错
库存服务库存扣除了3，订单服务没有生产订单
结果符合预期，也就是没有分布式事务情况下，数据不一致了
服务集成seata at seata-server 配置上传到nacos如果要让seata 识别某个或者某些服务，需要提前将一些配置上传到nacos上，上传可以使用nacos-config.sh 脚本
然后执行以下命令
sh nacos-config.sh -h 127.0.0.1
-h 是nacos 所在ip
在nacos-condig.sh 同级目录下创建config.txt
内容如下
transport.type=TCP transport.server=NIO transport.heartbeat=true transport.enableClientBatchSendRequest=true transport.threadFactory.bossThreadPrefix=NettyBoss transport.threadFactory.workerThreadPrefix=NettyServerNIOWorker transport.threadFactory.serverExecutorThreadPrefix=NettyServerBizHandler transport.threadFactory.shareBossWorker=false transport.threadFactory.clientSelectorThreadPrefix=NettyClientSelector transport.threadFactory.clientSelectorThreadSize=1 transport.threadFactory.clientWorkerThreadPrefix=NettyClientWorkerThread transport.threadFactory.bossThreadSize=1 transport.threadFactory.workerThreadSize=default transport.shutdown.wait=3 service.vgroupMapping.mini-cloud-authentication-center_tx_group=default service.vgroupMapping.mini-cloud-upms-center-biz_tx_group=default service.vgroupMapping.mini-cloud-simulate-order-biz_tx_group=default service.vgroupMapping.mini-cloud-simulate-goods-biz_tx_group=default service.default.grouplist=127.0.0.1:8091 service.enableDegrade=false service.disableGlobalTransaction=false client.rm.asyncCommitBufferLimit=10000 client.rm.lock.retryInterval=10 client.rm.lock.retryTimes=30 client.rm.lock.retryPolicyBranchRollbackOnConflict=true client.rm.reportRetryCount=5 client.rm.tableMetaCheckEnable=false client.rm.tableMetaCheckerInterval=60000 client.rm.sqlParserType=druid client.rm.reportSuccessEnable=false client.rm.sagaBranchRegisterEnable=false client.rm.tccActionInterceptorOrder=-2147482648 client.tm.commitRetryCount=5 client.tm.rollbackRetryCount=5 client.tm.defaultGlobalTransactionTimeout=60000 client.tm.degradeCheck=false client.tm.degradeCheckAllowTimes=10 client.tm.degradeCheckPeriod=2000 client.tm.interceptorOrder=-2147482648 store.mode=db store.lock.mode=db store.session.mode=db store.publicKey= store.file.dir=file_store/data store.file.maxBranchSessionSize=16384 store.file.maxGlobalSessionSize=512 store.file.fileWriteBufferCacheSize=16384 store.file.flushDiskMode=async store.file.sessionReloadReadSize=100 store.db.datasource=druid store.db.dbType=mysql store.db.driverClassName=com.mysql.jdbc.Driver store.db.url=jdbc:mysql://mini-cloud-mysql:3306/mini_cloud_seata?useUnicode=true&rewriteBatchedStatements=true store.db.user=root store.db.password=root store.db.minConn=5 store.db.maxConn=30 store.db.globalTable=global_table store.db.branchTable=branch_table store.db.queryLimit=100 store.db.lockTable=lock_table store.db.maxWait=5000 store.redis.mode=sentinel store.redis.single.host=127.0.0.1 store.redis.single.port=6379 store.redis.sentinel.masterName= store.redis.sentinel.sentinelHosts= store.redis.maxConn=10 store.redis.minConn=1 store.redis.maxTotal=100 store.redis.database=0 store.redis.password=123456 store.redis.queryLimit=100 server.recovery.committingRetryPeriod=1000 server.recovery.asynCommittingRetryPeriod=1000 server.recovery.rollbackingRetryPeriod=1000 server.recovery.timeoutRetryPeriod=1000 server.maxCommitRetryTimeout=-1 server.maxRollbackRetryTimeout=-1 server.rollbackRetryTimeoutUnlockEnable=false server.distributedLockExpireTime=10000 client.undo.dataValidation=true client.undo.logSerialization=jackson client.undo.onlyCareUpdateColumns=true server.undo.logSaveDays=7 server.undo.logDeletePeriod=86400000 client.undo.logTable=undo_log client.undo.compress.enable=true client.undo.compress.type=zip client.undo.compress.threshold=64k log.exceptionRate=100 transport.serialization=seata transport.compressor=none metrics.enabled=false metrics.registryType=compact metrics.exporterList=prometheus metrics.exporterPrometheusPort=9898
重点两个地方 ，第一是配置服务名
一般格式是服务名+_tx_group default是默认分组
第二是修改配置模式，我这里配置的是使用db，也就是连接mysql
执行命令后会看到参数都已经传到了nacos
订单服务集成seata
由于我们集成了shardingshpere读写分离分库分表，所以不能只用传统的seata，需要使用如下maven依赖
org.apache.shardingsphere sharding-transaction-base-seata-at
io.seata seata-spring-boot-starter
resources 目录下添加如下三个文件，库存服务也一样
file.conf
service {
vgroupMapping.mini-cloud-simulate-order-biz_tx_group = "default" #修改事务组名称为：my_test_tx_group，和客户端自定义的名称对应
#only support single node
default.grouplist = "127.0.0.1:8091"
#degrade current not support
enableDegrade = false
#disable
disable = false
disableGlobalTransaction = 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"
}
registry.conf
registry {
# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
type = "nacos"
loadBalance = "RandomLoadBalance"
loadBalanceVirtualNodes = 10
nacos {
application = "seata-server"
serverAddr = "127.0.0.1:8848"
group = "SEATA_GROUP"
namespace = ""
cluster = "default"
username = ""
password = ""
}
}
seata.conf
sharding {
transaction.seata.at.enable = true
}
client {
application.id = mini-cloud-simulate-order-biz
transaction.service.group = mini-cloud-simulate-order-biz_tx_group
}
库存服务集成seata
maven 依赖同上
file.conf
service {
vgroupMapping.mini-cloud-simulate-goods-biz_tx_group = "default" #修改事务组名称为：my_test_tx_group，和客户端自定义的名称对应
#only support single node
default.grouplist = "127.0.0.1:8091"
#degrade current not support
enableDegrade = false
#disable
disable = false
#disable seata
disableGlobalTransaction = 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"
}
registry.conf
registry {
# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
type = "nacos"
loadBalance = "RandomLoadBalance"
loadBalanceVirtualNodes = 10
nacos {
application = "seata-server"
serverAddr = "127.0.0.1:8848"
group = "SEATA_GROUP"
namespace = ""
cluster = "default"
username = ""
password = ""
}
}
seata.conf
sharding {
transaction.seata.at.enable = true
}
client {
application.id = mini-cloud-simulate-goods-biz
transaction.service.group = mini-cloud-simulate-goods-biz_tx_group
}
两个服务添加seataFilter，解决xid不传递问题
SeataFilter.java
@Component
public class SeataFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) servletRequest;
String xid = req.getHeader(RootContext.KEY_XID.toLowerCase());
boolean isBind = false;
if (StringUtils.isNotBlank(xid)) {
RootContext.bind(xid);
isBind = true;
}
try {
filterChain.doFilter(servletRequest, servletResponse);
} finally {
if (isBind) {
RootContext.unbind();
}
}
}
@Override
public void destroy() {
}
}
SeataXidRequestInterceptor.java
public class SeataXidRequestInterceptor implements RequestInterceptor {
@Override
public void apply(RequestTemplate template) {
String xid = RootContext.getXID();
if (StringUtils.isEmpty(xid)) {
return;
}
List fescarXid = new ArrayList<>();
fescarXid.add(xid);
template.header(RootContext.KEY_XID, fescarXid);
System.err.println("添加XID:" + fescarXid);
}
}
SeataConfiguration.java
@Configuration
public class SeataConfiguration {
@Bean
public RequestInterceptor requestInterceptor(){
return new SeataXidRequestInterceptor();
}
}
配置完毕，启动校验是否连接到seata server
信息显示注册成功，之所有有多条信息是因为我们有多个读写分离数据源，每个数据源都会注册
集成seata后再来测试一下上面的模拟订单库存失败场景发起端订单服务接口添加全局事务注解然后重启服务
恢复商品库存为10
再测执行创建订单接口
查看结果
订单服务报错回滚
库存服务也跟着回滚
查看数据库情况，确实回滚到了10 并没有多扣除库存
以上实际案例整明seata at确实可以达到分布式事务强一直性控制
