声明式接口调用：Feign源码剖析（5）Feign整合Ribbon的连接超时与重试机制

实验

  • 服务提供者ServiceA，5个实例，端口8081~8085
  • 服务消费者ServiceB，1个实例，端口9000
  • 注册中心，eureka-server，2个实例
  • SpringCloud版本，Hoxton.RELEASE
  • SpringBoot版本，2.2.1.RELEASE
  • SpringCloudStarterOpenFeign版本，2.2.0.RELEASE

对ServiceA的greeting接口稍加改造，用以模拟接口超时

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public String greeting(String name) {
    Integer port = environment.getProperty("local.server.port", Integer.class);
    try {
        log.info("[{}]进入漫长的等待...", port);
        Thread.sleep(5000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    return "hello," + name + ", came from " + port;
}

对于服务消费者ServiceB的配置如下

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ribbon:
  ConnectTimeout: 1000
  ReadTimeout: 1000
  OkToRetryOnAllOperations: true
  MaxAutoRetries: 1
  MaxAutoRetriesNextServer: 3

服务消费者B的日志如下

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-14:02:48.489 -DEBUG 13376 --- [nio-9000-exec-6] c.n.loadbalancer.ZoneAwareLoadBalancer   : Zone aware logic disabled or there is only one zone
-14:02:48.489 -DEBUG 13376 --- [nio-9000-exec-6] c.n.loadbalancer.LoadBalancerContext     : serviceA using LB returned Server: localhost:8081 for request http:///sayHello/sam
-14:02:49.497 -DEBUG 13376 --- [nio-9000-exec-6] c.n.l.reactive.LoadBalancerCommand       : Got error java.net.SocketTimeoutException: Read timed out when executed on server localhost:8081
-14:02:50.512 -DEBUG 13376 --- [nio-9000-exec-6] c.n.l.reactive.LoadBalancerCommand       : Got error java.net.SocketTimeoutException: Read timed out when executed on server localhost:8081
-14:02:50.512 -DEBUG 13376 --- [nio-9000-exec-6] c.n.loadbalancer.ZoneAwareLoadBalancer   : Zone aware logic disabled or there is only one zone
-14:02:50.512 -DEBUG 13376 --- [nio-9000-exec-6] c.n.loadbalancer.LoadBalancerContext     : serviceA using LB returned Server: localhost:8082 for request http:///sayHello/sam
-14:02:51.523 -DEBUG 13376 --- [nio-9000-exec-6] c.n.l.reactive.LoadBalancerCommand       : Got error java.net.SocketTimeoutException: Read timed out when executed on server localhost:8082
-14:02:52.534 -DEBUG 13376 --- [nio-9000-exec-6] c.n.l.reactive.LoadBalancerCommand       : Got error java.net.SocketTimeoutException: Read timed out when executed on server localhost:8082
-14:02:52.535 -DEBUG 13376 --- [nio-9000-exec-6] c.n.loadbalancer.ZoneAwareLoadBalancer   : Zone aware logic disabled or there is only one zone
-14:02:52.535 -DEBUG 13376 --- [nio-9000-exec-6] c.n.loadbalancer.LoadBalancerContext     : serviceA using LB returned Server: localhost:8084 for request http:///sayHello/sam
-14:02:53.544 -DEBUG 13376 --- [nio-9000-exec-6] c.n.l.reactive.LoadBalancerCommand       : Got error java.net.SocketTimeoutException: Read timed out when executed on server localhost:8084
-14:02:54.557 -DEBUG 13376 --- [nio-9000-exec-6] c.n.l.reactive.LoadBalancerCommand       : Got error java.net.SocketTimeoutException: Read timed out when executed on server localhost:8084
-14:02:54.557 -DEBUG 13376 --- [nio-9000-exec-6] c.n.loadbalancer.ZoneAwareLoadBalancer   : Zone aware logic disabled or there is only one zone
-14:02:54.557 -DEBUG 13376 --- [nio-9000-exec-6] c.n.loadbalancer.LoadBalancerContext     : serviceA using LB returned Server: localhost:8083 for request http:///sayHello/sam
-14:02:55.570 -DEBUG 13376 --- [nio-9000-exec-6] c.n.l.reactive.LoadBalancerCommand       : Got error java.net.SocketTimeoutException: Read timed out when executed on server localhost:8083
-14:02:56.574 -DEBUG 13376 --- [nio-9000-exec-6] c.n.l.reactive.LoadBalancerCommand       : Got error java.net.SocketTimeoutException: Read timed out when executed on server localhost:8083
-14:02:56.576 -ERROR 13376 --- [nio-9000-exec-6] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is feign.RetryableException: Read timed out executing GET http://serviceA/sayHello/sam] with root cause
-
java.net.SocketTimeoutException: Read timed out
  at java.net.SocketInputStream.socketRead0(Native Method) ~[na:1.8.0_291]
  at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) ~[na:1.8.0_291]
  at java.net.SocketInputStream.read(SocketInputStream.java:171) ~[na:1.8.0_291]
  at java.net.SocketInputStream.read(SocketInputStream.java:141) ~[na:1.8.0_291]
  at java.io.BufferedInputStream.fill(BufferedInputStream.java:246) ~[na:1.8.0_291]
  at java.io.BufferedInputStream.read1(BufferedInputStream.java:286) ~[na:1.8.0_291]
  at java.io.BufferedInputStream.read(BufferedInputStream.java:345) ~[na:1.8.0_291]
  at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:735) ~[na:1.8.0_291]
  at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:678) ~[na:1.8.0_291]
  at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1593) ~[na:1.8.0_291]
  at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498) ~[na:1.8.0_291]
  at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480) ~[na:1.8.0_291]
  at feign.Client$Default.convertResponse(Client.java:82) ~[feign-core-10.4.0.jar:na]
  at feign.Client$Default.execute(Client.java:78) ~[feign-core-10.4.0.jar:na]
  at org.springframework.cloud.openfeign.ribbon.FeignLoadBalancer.execute(FeignLoadBalancer.java:93) ~[spring-cloud-openfeign-core-2.2.0.RELEASE.jar:2.2.0.RELEASE]
  at org.springframework.cloud.openfeign.ribbon.FeignLoadBalancer.execute(FeignLoadBalancer.java:56) ~[spring-cloud-openfeign-core-2.2.0.RELEASE.jar:2.2.0.RELEASE]
  at com.netflix.client.AbstractLoadBalancerAwareClient$1.call(AbstractLoadBalancerAwareClient.java:104) ~[ribbon-loadbalancer-2.3.0.jar:2.3.0]
  at com.netflix.loadbalancer.reactive.LoadBalancerCommand$3$1.call(LoadBalancerCommand.java:303) ~[ribbon-loadbalancer-2.3.0.jar:2.3.0]
  at com.netflix.loadbalancer.reactive.LoadBalancerCommand$3$1.call(LoadBalancerCommand.java:287) ~[ribbon-loadbalancer-2.3.0.jar:2.3.0]
  at rx.internal.util.ScalarSynchronousObservable$3.call(ScalarSynchronousObservable.java:231) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.util.ScalarSynchronousObservable$3.call(ScalarSynchronousObservable.java:228) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.Observable.unsafeSubscribe(Observable.java:10327) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber$1.call(OperatorRetryWithPredicate.java:127) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.enqueue(TrampolineScheduler.java:73) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.schedule(TrampolineScheduler.java:52) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:79) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:45) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.util.ScalarSynchronousObservable$WeakSingleProducer.request(ScalarSynchronousObservable.java:276) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.Subscriber.setProducer(Subscriber.java:209) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.util.ScalarSynchronousObservable$JustOnSubscribe.call(ScalarSynchronousObservable.java:138) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.util.ScalarSynchronousObservable$JustOnSubscribe.call(ScalarSynchronousObservable.java:129) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.Observable.unsafeSubscribe(Observable.java:10327) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeConcatMap$ConcatMapSubscriber.drain(OnSubscribeConcatMap.java:286) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeConcatMap$ConcatMapSubscriber.onNext(OnSubscribeConcatMap.java:144) ~[rxjava-1.3.8.jar:1.3.8]
  at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:185) ~[ribbon-loadbalancer-2.3.0.jar:2.3.0]
  at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:180) ~[ribbon-loadbalancer-2.3.0.jar:2.3.0]
  at rx.Observable.unsafeSubscribe(Observable.java:10327) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeConcatMap.call(OnSubscribeConcatMap.java:94) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeConcatMap.call(OnSubscribeConcatMap.java:42) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.Observable.unsafeSubscribe(Observable.java:10327) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber$1.call(OperatorRetryWithPredicate.java:127) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.enqueue(TrampolineScheduler.java:73) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.schedule(TrampolineScheduler.java:52) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:79) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:45) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.util.ScalarSynchronousObservable$WeakSingleProducer.request(ScalarSynchronousObservable.java:276) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.Subscriber.setProducer(Subscriber.java:209) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.util.ScalarSynchronousObservable$JustOnSubscribe.call(ScalarSynchronousObservable.java:138) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.util.ScalarSynchronousObservable$JustOnSubscribe.call(ScalarSynchronousObservable.java:129) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.Observable.subscribe(Observable.java:10423) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.Observable.subscribe(Observable.java:10390) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.observables.BlockingObservable.blockForSingle(BlockingObservable.java:443) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.observables.BlockingObservable.single(BlockingObservable.java:340) ~[rxjava-1.3.8.jar:1.3.8]
  at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:112) ~[ribbon-loadbalancer-2.3.0.jar:2.3.0]
  at org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient.execute(LoadBalancerFeignClient.java:83) ~[spring-cloud-openfeign-core-2.2.0.RELEASE.jar:2.2.0.RELEASE]
  at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:110) ~[feign-core-10.4.0.jar:na]
  at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:80) ~[feign-core-10.4.0.jar:na]
  at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:103) ~[feign-core-10.4.0.jar:na]
  at com.sun.proxy.$Proxy113.sayHello(Unknown Source) ~[na:na]
  at cc.houqian.eurekalearn.serviceb.ServiceBController.greeting(ServiceBController.java:25) ~[classes/:na]
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_291]
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_291]
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_291]
  at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_291]
  at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:108) ~[spring-boot-actuator-2.2.1.RELEASE.jar:2.2.1.RELEASE]
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1579) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_291]
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_291]
  at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.27.jar:9.0.27]
  at java.lang.Thread.run(Thread.java:748) [na:1.8.0_291]

  • 负载均衡器ZoneAwareLoadBalancer总共选举了4次Server

    第几次 服务消费者ServiceB日志
    第一次 serviceA using LB returned Server: localhost:8081 for request http:///sayHello/sam
    第二次 serviceA using LB returned Server: localhost:8082 for request http:///sayHello/sam
    第三次 serviceA using LB returned Server: localhost:8084 for request http:///sayHello/sam
    第四次 serviceA using LB returned Server: localhost:8083 for request http:///sayHello/sam

    可见符合我们的预期，首次访问8081，请求+重试失败后，访问另外三个实例

  • 从服务提供者端验证请求了多少次
    8081被请求2次，首次是正常请求，失败，第二次是重试，同样失败

    Ribbon重试机制-服务提供者8081

    8081被请求2次，首次是正常请求，失败，第二次是重试，同样失败

    Ribbon重试机制-服务提供者8082

    8083被请求2次，首次是正常请求，失败，第二次是重试，同样失败
    Ribbon重试机制-服务提供者8083
    8084被请求2次，首次是正常请求，失败，第二次是重试，同样失败Ribbon重试机制-服务提供者8084

    8085没有被请求到
    Ribbon重试机制-服务提供者8085

总结

生产环境配置模版如下

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ribbon:
  ConnectTimeout: 1000
  ReadTimeout: 1000
  OkToRetryOnAllOperations: true
  MaxAutoRetries: 1
  MaxAutoRetriesNextServer: 3

  • ConnectTimeout
    建立Socket连接的超时时间。
    这个参数是在Feign使用自己的Client发送HTTP请求时使用，本质是HttpURLConnection#setConnectTimeout
    意思是发送请求前，建立socket连接得在这个时间内完成，如果超出时间，就会报java.net.SocketTimeoutException

  • ReadTimeout
    从Socket读取数据的超时时间，显然这指的是读取响应内容的时间

  • OkToRetryOnAllOperations
    调用远程服务发生任何超时异常，程序返回报错（比如500）等都会进行重试

  • MaxAutoRetries
    同一台机器被重试的次数

  • MaxAutoRetriesNextServer

    最多重试几台服务器

Retryer保持默认即可，即NEVER_RETRY，用现有的重试机制已经满足需求了

Feign-Feign-Ribbon超时与重试机制

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