8761 - was unable to refresh its cache! status = Cannot execute request on any known server

今天搭建Spring-Cloud-Eureka-Server 和client的demo，由于之前没有做过相关项目，碰到一个问题时，解决起来浪费了不少时间，问题如下：

client启动时，报了如下错误：

2017-09-18 11:27:32.317  WARN 2712 --- [freshExecutor-0] c.n.d.s.t.d.RetryableEurekaHttpClient    : Request execution failed with message: java.net.ConnectException: Connection refused: connect
2017-09-18 11:27:32.318 ERROR 2712 --- [freshExecutor-0] com.netflix.discovery.DiscoveryClient    : DiscoveryClient_TESTCLIENT/DESKTOP-DBS1AMN:testClient:8762 - was unable to refresh its cache! status = Cannot execute request on any known server

com.netflix.discovery.shared.transport.TransportException: Cannot execute request on any known server

找了几篇博客，通过不断的对比与测试，发现了问题所在：

在server端的application.yml中配置了登陆Eureka服务端的用户名和密码：

security:
basic:
enabled: true
user:
name: admin # login username
password: admin

解决方式：

1、删除用户名和密码配置，重启即可；

2、在客户端的application.yml中，serviceUrl配置时，加入用户名和密码：

serviceUrl:
defaultZone: http://username:password@localhost:8761/eureka/[/code] 
4000