此处两种情况
一种：security依赖和eureka的配置文件已配置security，查看两个项目下的注册地址是否写密码。
解决方法：重点在于defaultZone路径上的username+password
security:
basic:
enabled: true
user:
name: user
password: password123
server:
port: 8761
eureka:
client:
serviceUrl:
defaultZone: http://user:password@localhost:8761/eureka
另一种：当我pom上添加 spring-boot-starter-security 依赖后 为在eureka服务器的配置文件中配置相关的security配置，导致服务启动时注册失败
解决方法：将eureka服务上security依赖去掉或者配置上security配置，两个项目上的路径都写上用户名和密码
报错信息
2020-06-23 19:41:00.609 INFO 16496 --- [ main] com.netflix.discovery.DiscoveryClient : Application version is -1: true
2020-06-23 19:41:00.609 INFO 16496 --- [ main] com.netflix.discovery.DiscoveryClient : Getting all instance registry info from the eureka server
2020-06-23 19:41:01.246 WARN 16496 --- [ main] c.n.d.s.t.d.RetryableEurekaHttpClient : Request execution failure with status code 401; retrying on another server if available
2020-06-23 19:41:01.256 ERROR 16496 --- [ main] com.netflix.discovery.DiscoveryClient : DiscoveryClient_xxxxxx/xxxxx:microservice-provider-user:7900 - 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
at com.netflix.discovery.shared.transport.decorator.RetryableEurekaHttpClient.execute(RetryableEurekaHttpClient.java:111) ~[eureka-client-1.4.12.jar:1.4.12]
at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.getApplications(EurekaHttpClientDecorator.java:134) ~[eureka-client-1.4.12.jar:1.4.12]
at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$6.execute(EurekaHttpClientDecorator.java:137) ~[eureka-client-1.4.12.jar:1.4.12]
at com.netflix.discovery.shared.transport.decorator.SessionedEurekaHttpClient.execute(SessionedEurekaHttpClient.java:77) ~[eureka-client-1.4.12.jar:1.4.12]
at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.getApplications(EurekaHttpClientDecorator.java:134) ~[eureka-client-1.4.12.jar:1.4.12]
at com.netflix.discovery.DiscoveryClient.getAndStoreFullRegistry(DiscoveryClient.java:1030) [eureka-client-1.4.12.jar:1.4.12]
at com.netflix.discovery.DiscoveryClient.fetchRegistry(DiscoveryClient.java:944) [eureka-client-1.4.12.jar:1.4.12]
at com.netflix.discovery.DiscoveryClient.<init>(DiscoveryClient.java:444) [eureka-client-1.4.12.jar:1.4.12]
at com.netflix.discovery.DiscoveryClient.<init>(DiscoveryClient.java:304) [eureka-client-1.4.12.jar:1.4.12]
at org.springframework.cloud.netflix.eureka.CloudEurekaClient.<init>(CloudEurekaClient.java:51) [spring-cloud-netflix-eureka-client-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration.eurekaClient(EurekaClientAutoConfiguration.java:192) [spring-cloud-netflix-eureka-client-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration$$EnhancerBySpringCGLIB$$1cfb396c.CGLIB$eurekaClient$0(<generated>) [spring-cloud-netflix-eureka-client-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration$$EnhancerBySpringCGLIB$$1cfb396c$$FastClassBySpringCGLIB$$954b35a3.invoke(<generated>) [spring-cloud-netflix-eureka-client-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) [spring-core-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:356) [spring-context-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration$$EnhancerBySpringCGLIB$$1cfb396c.eurekaClient(<generated>) [spring-cloud-netflix-eureka-client-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_144]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_144]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_144]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_144]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1128) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1022) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:512) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$2.getObject(AbstractBeanFactory.java:345) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.cloud.context.scope.GenericScope$BeanLifecycleWrapper.getBean(GenericScope.java:359) [spring-cloud-context-1.1.6.RELEASE.jar:1.1.6.RELEASE]
at org.springframework.cloud.context.scope.GenericScope.get(GenericScope.java:176) [spring-cloud-context-1.1.6.RELEASE.jar:1.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:340) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) [spring-beans-4.3.4.RELEASE.jar:4.3.4.RELEASE]