分布式事务Seata知识点之 -- Seata、Dubbo 和 Nacos 来保证业务数据的一致性

目录

1.重点是seata server的配置与启动：

1.1 将seata-server注册到nacos -- 服务注册

1.2 nacos既能做为注册中心，又能做为配置管理中心

1.3 seata-server的事务log存储相关配置：

1.4 启动seata-server

2.seata-server的client端配置：

3.启动微服务并测试

---

运行seata 实例： https://github.com/seata/seata-samples/tree/master/nacos

• nacos版本：1.4.2
• seata-server版本：1.4.2

按照user guide的步骤，一步一步的完成Seata、Dubbo和Nacos 集成

1.重点是seata server的配置与启动：

1.1 将seata-server注册到nacos -- 服务注册

修改seata-server中的conf目录下的registry.conf文件，选择nacos做为注册中心。

registry {
  # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
  type = "nacos"

  nacos {
    application = "seata-server"
    serverAddr = "127.0.0.1:8848"
    group = "SEATA_GROUP"
    namespace = ""
    cluster = "default"
    username = ""
    password = ""
  }
  eureka {
    serviceUrl = "http://localhost:8761/eureka"
    application = "default"
    weight = "1"
  }
..................................................

1.2 nacos既能做为注册中心，又能做为配置管理中心

还是修改seata-server中的conf目录下的registry.conf文件，选择nacos做为配置中心，集中管理各个微服务的配置信息。

config {
  # file、nacos 、apollo、zk、consul、etcd3
  type = "nacos"

  nacos {
    serverAddr = "127.0.0.1:8848"
    namespace = ""
    group = "SEATA_GROUP"
    username = ""
    password = ""
    #dataId = "seataServer.properties"
  }
  consul {
    serverAddr = "127.0.0.1:8500"
    aclToken = ""
  }
.............................................

将seata-server的配置导入到nacos

参考文章：https://blog.csdn.net/qq853632587/article/details/111644295 按照里面的步骤，将seata-server配置导入到nacos。下面是成功之后的截图

1.3 seata-server的事务log存储相关配置：

修改seata-server中的conf目录下的文件file.conf，选择使用db去存储事务log

## transaction log store, only used in seata-server
store {
  ## store mode: file、db、redis
  mode = "db"
  ## rsa decryption public key
  publicKey = ""
  ## file store property
  file {
    ## store location dir
    dir = "sessionStore"
    # branch session size , if exceeded first try compress lockkey, still exceeded throws exceptions
    maxBranchSessionSize = 16384
    # globe session size , if exceeded throws exceptions
    maxGlobalSessionSize = 512
    # file buffer size , if exceeded allocate new buffer
    fileWriteBufferCacheSize = 16384
    # when recover batch read size
    sessionReloadReadSize = 100
    # async, sync
    flushDiskMode = async
  }

  ## database store property
  db {
    ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp)/HikariDataSource(hikari) etc.
    datasource = "druid"
    ## mysql/oracle/postgresql/h2/oceanbase etc.
    dbType = "mysql"
    driverClassName = "com.mysql.jdbc.Driver"
    ## if using mysql to store the data, recommend add rewriteBatchedStatements=true in jdbc connection param
    url = "jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true"
    user = "root"
    password = "123456"
    minConn = 5
    maxConn = 100
    globalTable = "global_table"
    branchTable = "branch_table"
    lockTable = "lock_table"
    queryLimit = 100
    maxWait = 5000
  }

1.4 启动seata-server

seata-server.bat -h 127.0.0.1 -m db

启动成功之后，seata-server做为一个微服务，根据上面的配置，被注册到nacos。

2.seata-server的client端配置：

谁是seata-server的client？ 当然是我们的应用程序，我们的应用程序中依赖这个jar包 -- seata-all

    
        
            io.seata
            seata-all
            
            1.3.0
        

 client端也是需要进行配置的，具体的需要在file.conf和registry.conf文件中进行配置

NOTE： serverAddr和namespace与Server端一致，clusterName与Server端cluster一致

3.启动微服务并测试

需要将seata的java客户端的版本换成1.3.0，不然会报错儿，具体解决问题的过程，请参考文章：https://blog.csdn.net/wdquan19851029/article/details/116751027

    
        
            io.seata
            seata-all
            
            1.3.0
    

• 启动 DubboAccountServiceStarter
• 启动 DubboOrderServiceStarter
• 启动 DubboStorageServiceStarter

启动完成可在 Nacos 控制台服务列表 看到启动完成的三个 provider

最后，启动 DubboBusinessTester 进行测试

订单创建完成：

货物库存由100变成98：

资金账户的钱由999变成599：