《SpringCloud Alibaba 微服務架構》專題(十)-Spring Cloud Alibaba之Feign調用Ribbon+Hystrix請求逾時

1.什麼是Feign逾時

1.使用

Feign

調用接口分為兩層，

Ribbon

的調用和

Hystrix

的調用，是以

Ribbon

的逾時時間和

Hystrix

的逾時時間的結合就是

Feign

的逾時時間。

2.一般情況下都是

Ribbon

的逾時時間（<）

Hystrix

的逾時時間（因為涉及到

Ribbon

的重試機制），如果

Ribbon

的逾時時間大于Hystrix的逾時時間，對于

Ribbon

的重試是沒有意義的（

Hystrix

逾時熔斷了，

Ribbon

無法重試）。

提示：

預設情況下，如果Ribbon沒有配置重試時間和次數，預設是1S逾時，預設會自動重試1次。
預設情況下，如果Hystrix沒有配置重試時間和次數，預設是1S逾時，預設會自動重試1次。

2.Ribbon逾時

問題：在服務提供者的接口上加休眠5秒，測試Feign調用的時候是否會逾時？

@GetMapping(value = "/getProductInfo/{productId}")
public String getProductInfo(@PathVariable("productId") String productId) {
    log.info("請求進來啦");
    try {
        log.info("模拟服務端逾時");
        Thread.sleep(5000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    } finally {
    }
    return "Hello Nacos Discovery " + productId;
}

接口提供方和接口調用方的

application.yml

都是如下：

server:
  port: 8716
spring:
  cloud:
    nacos:
      discovery:
        #服務注冊與發現位址
        server-addr: 127.0.0.1:8848
        #開啟服務注冊與發現功能
        enabled: true
  application:
    name: nacos-product

通路接口：http://localhost:8777/getProduct/100 控制台異常如下：

《SpringCloud Alibaba 微服務架構》專題(十)-Spring Cloud Alibaba之Feign調用Ribbon+Hystrix請求逾時

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is feign.RetryableException: Read timed out executing GET http://nacos-product/getProductInfo/100
  at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:503) ~[jakarta.servlet-api-4.0.3.jar:4.0.3]
  at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:590) ~[jakarta.servlet-api-4.0.3.jar:4.0.3]
  at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.RedirectDirHandler.handleRequest(RedirectDirHandler.java:68) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:132) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) ~[undertow-core-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46) ~[undertow-core-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60) ~[undertow-core-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77) ~[undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43) ~[undertow-core-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) ~[undertow-core-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) ~[undertow-core-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:269) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:78) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:133) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:130) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:249) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:78) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:99) [undertow-servlet-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.server.Connectors.executeRootHandler(Connectors.java:376) [undertow-core-2.0.29.Final.jar:2.0.29.Final]
  at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830) [undertow-core-2.0.29.Final.jar:2.0.29.Final]
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_40]
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_40]
  at java.lang.Thread.run(Thread.java:745) [na:1.8.0_40]
Caused by: feign.RetryableException: Read timed out executing GET http://nacos-product/getProductInfo/100
  at feign.FeignException.errorExecuting(FeignException.java:249) ~[feign-core-10.7.4.jar:na]
  at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:120) ~[feign-core-10.7.4.jar:na]
  at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:80) ~[feign-core-10.7.4.jar:na]
  at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:100) ~[feign-core-10.7.4.jar:na]
  at com.sun.proxy.$Proxy85.getProductInfo(Unknown Source) ~[na:na]
  at com.bruce.controller.OrderController.getProduct(OrderController.java:25) ~[classes/:na]
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_40]
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_40]
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_40]
  at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_40]
  at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.4.RELEASE.jar:5.2.4.RELEASE]
  ... 47 common frames omitted
Caused by: java.net.SocketTimeoutException: Read timed out
  at java.net.SocketInputStream.socketRead0(Native Method) ~[na:1.8.0_40]
  at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) ~[na:1.8.0_40]
  at java.net.SocketInputStream.read(SocketInputStream.java:170) ~[na:1.8.0_40]
  at java.net.SocketInputStream.read(SocketInputStream.java:141) ~[na:1.8.0_40]
  at java.io.BufferedInputStream.fill(BufferedInputStream.java:246) ~[na:1.8.0_40]
  at java.io.BufferedInputStream.read1(BufferedInputStream.java:286) ~[na:1.8.0_40]
  at java.io.BufferedInputStream.read(BufferedInputStream.java:345) ~[na:1.8.0_40]
  at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:704) ~[na:1.8.0_40]
  at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:647) ~[na:1.8.0_40]
  at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1535) ~[na:1.8.0_40]
  at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1440) ~[na:1.8.0_40]
  at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480) ~[na:1.8.0_40]
  at feign.Client$Default.convertResponse(Client.java:78) ~[feign-core-10.7.4.jar:na]
  at feign.Client$Default.execute(Client.java:74) ~[feign-core-10.7.4.jar:na]
  at org.springframework.cloud.openfeign.ribbon.FeignLoadBalancer.execute(FeignLoadBalancer.java:93) ~[spring-cloud-openfeign-core-2.2.2.RELEASE.jar:2.2.2.RELEASE]
  at org.springframework.cloud.openfeign.ribbon.FeignLoadBalancer.execute(FeignLoadBalancer.java:56) ~[spring-cloud-openfeign-core-2.2.2.RELEASE.jar:2.2.2.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$3.call(ScalarSynchronousObservable.java:228) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.Observable.unsafeSubscribe(Observable.java:10327) ~[rxjava-1.3.8.jar:1.3.8]
  at rx.internal.operators.OnSubscribeConcatMap$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-2.2.2.RELEASE.jar:2.2.2.RELEASE]
  at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:110) ~[feign-core-10.7.4.jar:na]
  ... 64 common frames omitted

分析：出現這個異常的時候，起初我不知道究竟是

Hystrix

斷路器走熔斷了還是

Ribbon

處理請求逾時了，通過觀察日志和做測試，我發現了錯誤日志是由：

org.springframework.cloud.openfeign.ribbon.FeignLoadBalancer

包列印出來的，那麼我就很确定這是

Ribbon

處理請求逾時了，因為我設定了接口提供方休眠

秒，而Ribbon的預設逾時是

秒，而預設情況下在使用Feign時，

Hystrix預設是未開啟的

，這樣就更加肯定這是Ribbon逾時，那麼如何處理呢，見後文。

org.springframework.cloud.openfeign.ribbon.FeignLoadBalancer.execute(FeignLoadBalancer.java:93) ~[spring-cloud-openfeign-core-2.1.2.RELEASE.jar:2.1.2.RELEASE]

解決：服務調用方

application.yml

加入

Ribbon

請求處理逾時和連接配接逾時，這裡需要注意一下，我們在服務提供方的接口裡設定休眠的時間是5秒，是以這裡在設定

Ribbon

的逾時時間時，需要大于5秒，不然起不到作用。

server:
  port: 8777
spring:
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
        enabled: true
  application:
    name: nacos-order
# 調用端比對值
ribbon:
  ReadTimeout: 6000
  ConnectTimeout: 5000

再次請求：http://localhost:8777/getProduct/100

正如我們初步的判斷，上述異常在Feign消費服務，

Feign

中的

Hystrix

預設是未開啟的，是以這個問題是由Ribbon逾時引起的。

3.Hystrix逾時

問題：在服務提供者的接口上加休眠5秒，測試Feign調用的時候是否會逾時？

@GetMapping(value = "/getProductInfo/{productId}")
public String getProductInfo(@PathVariable("productId") String productId) {
    log.info("請求進來啦");
    try {
        log.info("模拟服務端逾時");
        Thread.sleep(5000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    } finally {
    }
    return "Hello Nacos Discovery " + productId;
}

接口提供方的

application.yml

配置改成如下，為了探究

Hystrix

我們去掉

Ribbon

的逾時配置，開啟

Feign

中的

Hystrix

：

通路接口：http://localhost:8777/getProduct/100 控制台異常如下：

2021-02-20 10:44:54.878 ERROR 8012 --- [ HystrixTimer-1] c.b.client.OrderFeignFallbackFactory     : 調用異常：com.netflix.hystrix.exception.HystrixTimeoutException
2021-02-20 10:44:54.881  INFO 8012 --- [  XNIO-1 task-1] com.bruce.controller.OrderController     : 調用服務結束： 開啟斷路-fallback; reason was: com.netflix.hystrix.exception.HystrixTimeoutException
2021-02-20 10:44:55.075  INFO 8012 --- [erListUpdater-0] c.netflix.config.ChainedDynamicProperty  : Flipping property: nacos-product.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647

控制台列印日志：

分析：從異常的日志來看，服務調用逾時了，逾時後

Hystrix

立即進行了服務的熔斷，走了回調方法

OrderFeignFallbackFactory

，輸出了服務熔斷後我們定制的Msg，那麼如何解決這個逾時問題呢？

package com.bruce.client;

import feign.hystrix.FallbackFactory;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

/**
 * @BelongsProject: springcloud-alibaba-nacos
 * @BelongsPackage: com.bruce.client
 * @CreateTime: 2021-02-20 10:42
 * @Description: TODO
 */
@Component
@Slf4j
public class OrderFeignFallbackFactory implements FallbackFactory<OrderFeign> {
    @Override
    public OrderFeign create(final Throwable throwable) {
        log.error("調用異常：" + throwable.toString());
        return new OrderFeign() {
            @Override
            public String getProductInfo(String string) {
                return "開啟斷路-fallback; reason was: " + throwable.toString();
            }
        };
    }
}

解決：在接口調用方

application.yml

加入

Hystrix

逾時配置，同樣這裡需要注意的是，

Hystrix

預設的逾時時間是

秒，而我們在服務提供方的接口裡設定休眠的時間是5秒，是以這裡在設定Hystrix的逾時時間時，需要大于

秒，不然起不到作用防止逾時的作用。

server:
  port: 8777
spring:
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
        enabled: true
  application:
    name: nacos-order

feign:
  hystrix:
    enabled: true

hystrix:
  command:
    default:
      execution:
        timeout:
          enabled: true
        isolation:
          thread:
            timeoutInMilliseconds: 60000

#ribbon:
#  ReadTimeout: 6000
#  ConnectTimeout: 5000

再次通路接口：http://localhost:8777/getProduct/100 控制台異常如下：

控制台異常如下：

分析：開啟了Hystrix斷路器并且設定了

Hystrix

的逾時時間為6秒，但是這個時候Ribbon處理請求卻逾時了。分析下面這行異常日志：

RetryableException

大概意思是重試異常，查閱資料得知，Ribbon在逾時後會進行重試的，因為沒有對

Ribbon

逾時進行處理，但是開啟了

Hystirx

的斷路器功能和設定其逾時，是以

Ribbon

在處理請求逾時的時候，Hystirx就出來起作用了，對服務進行熔斷，降級處理，進而進入回調方法

OrderFeignFallbackFactory

，傳回友好提示起到服務保護作用。

調用異常：feign.RetryableException: Read timed out executing GET http://nacos-product/getProductInfo/1010110

總結：通過上述分析，那麼在開啟Hystrix斷路器功能之後就需要對

Ribbon

進行逾時設定了，兩者在碰到Feign時，需要協同作戰，或者更粗暴點直接不開啟Hystrix斷路器功能，但是這種方式極不推薦，高并發的項目中服務保護必不可少，是以我們需要将

Ribbon

與Hystrix結合使用，那麼接下來我們需要着重讨論

Ribbon

與

Hystrix

如何協同作戰。

4.在Feign中禁用Hystrix

禁用Hystrix:

參考官網資料： https://cloud.spring.io/spring-cloud-static/spring-cloud-openfeign/2.2.2.RELEASE/reference/html/#spring-cloud-feign-hystrix

要基于每個用戶端禁用

Hystrix

支援，請建立

Feign.Builder

具有“原型”範圍的香草，這段話摘自官網，例如：

package com.bruce.client;

import feign.Feign;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;

@Configuration
public class FooConfiguration {
    @Bean
    @Scope("prototype")
    public Feign.Builder feignBuilder() {
        return Feign.builder();
    }
}

5.同時設定Ribbon逾時和Hystrix逾時

Feign

調用時同時設定

Ribbon

逾時和

Hystrix

逾時，

application.yml

配置如下

server:
  port: 8777
spring:
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
        enabled: true
  application:
    name: nacos-order

feign:
  hystrix:
    enabled: true
hystrix:
  command:
    default:
      execution:
        timeout:
          enabled: true
        isolation:
          thread:
            timeoutInMilliseconds: 120000
ribbon:
  ReadTimeout: 6000
  ConnectTimeout: 5000

通路接口： http://localhost:8777/getProduct/100

7.Ribbon逾時值和Hystrix逾時值如何設定？

注意： Ribbon逾時+Hystrix逾時= Feign逾時

7.1.Feign逾時結論

使用 Feign 調用接口分兩層， ribbon 的調用和 hystrix 的調用，是以 ribbon 的逾時時間和 Hystrix 的逾時時間的結合就是 Feign 的逾時時間
一般情況下都是 ribbon的逾時時間 （<） hystrix的逾時時間 （因為涉及到ribbon的重試機制），如果ribbon的逾時時間大于 hystrix 的逾時時間，對于 ribbon 的重試是沒有意義的（ hystrix 逾時熔斷了， ribbon 無法重試），預設我項目中是沒有配置 ribbon 的重試的，但是需要注意的是無論是否需要配置ribbon逾時時的重試次數， hystrix 的逾時都是需要大于 ribbon 的逾時。

7.2.ribbon的重試機制

ribbon:
  OkToRetryOnAllOperations: false #對所有操作請求都進行重試,預設false
  ReadTimeout: 5000   #負載均衡逾時時間，預設值5000
  ConnectTimeout: 2000 #ribbon請求連接配接的逾時時間，預設值2000
  MaxAutoRetries: 0     #對目前執行個體的重試次數，預設0
  MaxAutoRetriesNextServer: 1 #對切換執行個體的重試次數，預設1
hystrix:
  command:
    default:  #default全局有效，service id指定應用有效
      execution:
        timeout:
          enabled: true
        isolation:
          thread:
            timeoutInMilliseconds: 10000 #斷路器逾時時間，預設1000ms

《SpringCloud Alibaba 微服務架構》專題(十)-Spring Cloud Alibaba之Feign調用Ribbon+Hystrix請求逾時

目錄

1.什麼是Feign逾時

2.Ribbon逾時

3.Hystrix逾時

4.在Feign中禁用Hystrix

5.同時設定Ribbon逾時和Hystrix逾時

7.Ribbon逾時值和Hystrix逾時值如何設定？

7.1.Feign逾時結論

7.2.ribbon的重試機制

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