聊聊springcloud的serviceRegistryEndpoint

序

本文主要研究一下springcloud的serviceRegistryEndpoint

实例

GET /actuator/service-registry

{
  "overriddenStatus": "UNKNOWN",
  "status": "UP"
}

如果eureka挂了，则返回

HTTP/1.1 500
Content-Type: application/vnd.spring-boot.actuator.v2+json;charset=UTF-8
Transfer-Encoding: chunked
Date: Sat, 28 Apr 2018 14:44:58 GMT
Connection: close

{"timestamp":"2018-04-28T14:44:58.765+0000","status":500,"error":"Internal Server Error","message":"Cannot execute request on any known server","path":"/actuator/service-registry"}

后台日志

2018-04-28 22:46:12 ERROR [organization-service,,,] Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is com.netflix.discovery.shared.transport.TransportException: Cannot execute request on any known server] with root cause
com.netflix.discovery.shared.transport.TransportException: Cannot execute request on any known server
    at com.netflix.discovery.shared.transport.decorator.RetryableEurekaHttpClient.execute(RetryableEurekaHttpClient.java:112) ~[eureka-client-1.8.8.jar:1.8.8]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.getInstance(EurekaHttpClientDecorator.java:224) ~[eureka-client-1.8.8.jar:1.8.8]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$12.execute(EurekaHttpClientDecorator.java:227) ~[eureka-client-1.8.8.jar:1.8.8]
    at com.netflix.discovery.shared.transport.decorator.SessionedEurekaHttpClient.execute(SessionedEurekaHttpClient.java:77) ~[eureka-client-1.8.8.jar:1.8.8]
    at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.getInstance(EurekaHttpClientDecorator.java:224) ~[eureka-client-1.8.8.jar:1.8.8]
    at org.springframework.cloud.netflix.eureka.CloudEurekaClient.getInstanceInfo(CloudEurekaClient.java:79) ~[spring-cloud-netflix-eureka-client-2.0.0.RC1.jar:2.0.0.RC1]
    at org.springframework.cloud.netflix.eureka.serviceregistry.EurekaServiceRegistry.getStatus(EurekaServiceRegistry.java:96) ~[spring-cloud-netflix-eureka-client-2.0.0.RC1.jar:2.0.0.RC1]
    at org.springframework.cloud.netflix.eureka.serviceregistry.EurekaServiceRegistry.getStatus(EurekaServiceRegistry.java:33) ~[spring-cloud-netflix-eureka-client-2.0.0.RC1.jar:2.0.0.RC1]
    at org.springframework.cloud.client.serviceregistry.endpoint.ServiceRegistryEndpoint.getStatus(ServiceRegistryEndpoint.java:68) ~[spring-cloud-commons-2.0.0.RC1.jar:2.0.0.RC1]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_71]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_71]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_71]
    at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_71]
    at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:223) ~[spring-core-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.boot.actuate.endpoint.invoke.reflect.ReflectiveOperationInvoker.invoke(ReflectiveOperationInvoker.java:76) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.actuate.endpoint.annotation.AbstractDiscoveredOperation.invoke(AbstractDiscoveredOperation.java:61) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.actuate.endpoint.web.servlet.AbstractWebMvcEndpointHandlerMapping$ServletWebOperationAdapter.handle(AbstractWebMvcEndpointHandlerMapping.java:243) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.actuate.endpoint.web.servlet.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(AbstractWebMvcEndpointHandlerMapping.java:299) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_71]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_71]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_71]
    at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_71]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:158) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:126) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:111) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:84) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.springframework.cloud.sleuth.instrument.web.ExceptionLoggingFilter.doFilter(ExceptionLoggingFilter.java:48) ~[spring-cloud-sleuth-core-2.0.0.RC1.jar:2.0.0.RC1]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at brave.servlet.TracingFilter.doFilter(TracingFilter.java:76) ~[brave-instrumentation-servlet-4.19.0.jar:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_71]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_71]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.29.jar:8.5.29]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_71]

POST /actuator/service-registry

curl -i -H "Content-Type: application/json" -X POST -d '{"status":"DOWN"}' http://localhost:8080/actuator/service-registry
HTTP/1.1 200
Content-Length: 0
Date: Sat, 28 Apr 2018 14:53:50 GMT

在查看则返回

{
  "overriddenStatus": "DOWN",
  "status": "DOWN"
}

再去eureka界面看，则会看到该服务已经标记为DOWN

ServiceRegistryAutoConfiguration

spring-cloud-commons-2.0.0.RC1-sources.jar!/org/springframework/cloud/client/serviceregistry/ServiceRegistryAutoConfiguration.java

@Configuration
public class ServiceRegistryAutoConfiguration {

    @ConditionalOnBean(ServiceRegistry.class)
    @ConditionalOnClass(Endpoint.class)
    protected class ServiceRegistryEndpointConfiguration {
        @Autowired(required = false)
        private Registration registration;

        @Bean
        @ConditionalOnEnabledEndpoint
        public ServiceRegistryEndpoint serviceRegistryEndpoint(ServiceRegistry serviceRegistry) {
            ServiceRegistryEndpoint endpoint = new ServiceRegistryEndpoint(serviceRegistry);
            endpoint.setRegistration(registration);
            return endpoint;
        }
    }
}

这里通过serviceRegistry创建了一个ServiceRegistryEndpoint

ServiceRegistryEndpoint

spring-cloud-commons-2.0.0.RC1-sources.jar!/org/springframework/cloud/client/serviceregistry/endpoint/ServiceRegistryEndpoint.java

/**
 * Endpoint to display and set the service instance status using the service registry.
 *
 * @author Spencer Gibb
 */
@SuppressWarnings("unchecked")
@Endpoint(id = "service-registry")
public class ServiceRegistryEndpoint {

    private final ServiceRegistry serviceRegistry;

    private Registration registration;

    public ServiceRegistryEndpoint(ServiceRegistry<?> serviceRegistry) {
        this.serviceRegistry = serviceRegistry;
    }

    public void setRegistration(Registration registration) {
        this.registration = registration;
    }

    @WriteOperation
    public ResponseEntity<?> setStatus(String status) {
        Assert.notNull(status, "status may not by null");

        if (this.registration == null) {
            return ResponseEntity.status(HttpStatus.NOT_FOUND).body("no registration found");
        }

        this.serviceRegistry.setStatus(this.registration, status);
        return ResponseEntity.ok().build();
    }

    @ReadOperation
    public ResponseEntity getStatus() {
        if (this.registration == null) {
            return ResponseEntity.status(HttpStatus.NOT_FOUND).body("no registration found");
        }

        return ResponseEntity.ok().body(this.serviceRegistry.getStatus(this.registration));
    }

}

这里有一个read操作用来获取当前registration的状态，还有一个write操作来设置registration的状态

小结

springcloud提供了一个service-registry的actuator，可以用来查看或更改当前服务在服务注册中心的Registration的状态。对于eureka来说，这些状态有UP,DOWN,OUT_OF_SERVICE,UNKNOWN这几类。

doc

• ServiceRegistry