nacos启动出现Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'memoryMonitor' defined in URL [jar:file:/D:/bangong/nacos-server-2.1.0/nacos/target/nacos-server.jar!/BOOT-INF/lib/nacos-config-2.1.0.jar!/com/alibaba/nacos/config/server/monitor/MemoryMonitor.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'asyncNotifyService': Unsatisfied dependency expressed through field 'dumpService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'externalDumpService': Invocation of init method failed; nested exception is ErrCode:500, ErrMsg:Nacos Server did not start because dumpservice bean construction failure : No DataSource set

这个错误是由于Nacos启动时出现了数据源初始化的问题。具体来说，它的异步通知服务（asyncNotifyService）依赖于一个名为dumpService的Bean，而这个Bean的初始化失败了，原因是没有设置数据源（No DataSource set）。

解决这个问题的方法是，检查Nacos配置文件中是否正确配置了数据源相关信息，比如数据库连接地址、用户名和密码等。如果配置正确但仍然无法解决问题，可以尝试升级Nacos版本或者重新安装Nacos。