我分别用8083，8086的端口启动user-srv服务。在注册中心也能发现这两个服务。但是我在api-gateway中调用user-srv服务的时候，报如下错误

com.mooc.house.api.utils.RestException: sendReq error by No instances available for user

at com.mooc.house.api.utils.Rests.sendReq(Rests.java:65) ~[classes/:?]

at com.mooc.house.api.utils.Rests.exc(Rests.java:28) ~[classes/:?]

at com.mooc.house.api.utils.Rests.exc(Rests.java:24) ~[classes/:?]

at com.mooc.house.api.dao.UserDao.getAgentList(UserDao.java:161) ~[classes/:?]

at com.mooc.house.api.dao.UserDao$$FastClassBySpringCGLIB$$8ddd603e.invoke(<generated>) ~[classes/:?]

at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738) ~[spring-aop-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) ~[spring-aop-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673) ~[spring-aop-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at com.mooc.house.api.dao.UserDao$$EnhancerBySpringCGLIB$$2906ff95.getAgentList(<generated>) ~[classes/:?]

at com.mooc.house.api.service.AgencyService.getAllAgent(AgencyService.java:36) ~[classes/:?]

at com.mooc.house.api.controller.AgencyController.agentList(AgencyController.java:69) ~[classes/:?]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_151]

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_151]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_151]

at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_151]

at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55) ~[spring-boot-1.4.7.RELEASE.jar:1.4.7.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.zalando.logbook.servlet.NormalStrategy.doFilter(NormalStrategy.java:42) ~[logbook-servlet-1.3.0.jar:?]

at org.zalando.logbook.servlet.LogbookFilter.doFilter(LogbookFilter.java:33) ~[logbook-servlet-1.3.0.jar:?]

at org.zalando.logbook.servlet.HttpFilter.doFilter(HttpFilter.java:32) ~[logbook-servlet-1.3.0.jar:?]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:105) ~[spring-boot-actuator-1.4.7.RELEASE.jar:1.4.7.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.cloud.sleuth.instrument.web.TraceFilter.doFilter(TraceFilter.java:150) ~[spring-cloud-sleuth-core-1.1.4.RELEASE.jar:1.1.4.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:106) ~[spring-boot-actuator-1.4.7.RELEASE.jar:1.4.7.RELEASE]

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.9.RELEASE.jar:4.3.9.RELEASE]

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_151]

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_151]

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-8.5.15.jar:8.5.15]

at java.lang.Thread.run(Thread.java:748) [?:1.8.0_151]