Spring-cloud Zuul实例关闭时重试

Question

使用Spring-cloud Angel.sr6:

下面是我使用@enablezuulproxy的Spring-boot应用程序的配置：

server.port=8765

ribbon.ConnectTimeout=500
ribbon.ReadTimeout=5000
ribbon.MaxAutoRetries=1
ribbon.MaxAutoRetriesNextServer=1
ribbon.OkToRetryOnAllOperations=true

zuul.routes.service-id.retryable=true

我有2个service-id实例在随机端口上运行。这些实例以及Zuul实例都成功注册到Eureka中，我可以通过访问http://localhost:8765/service-id/访问2service-id实例上的RESTfulendpoint....并发现它们是以循环方式平衡的。

我想杀死其中一个service-id实例，并且当该不起作用的实例是下一个要转发的实例时，让Zuul尝试联系它，失败后再用另一个实例重试。

这是可能的，还是我误读了文档？当我尝试上面的配置时，“指定”到不起作用的实例的请求以500转发错误失败。来自Zuul StackTrace：

com.netflix.zuul.exception.ZuulException: Forwarding error
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.forward(RibbonRoutingFilter.java:140)

....

Caused by: com.netflix.hystrix.exception.HystrixRuntimeException: service-idRibbonCommand timed-out and no fallback available

随后的请求按预期成功。这种行为一直持续到不起作用的实例从Zuul的注册表中删除为止。

编辑：更新到brixton.m5。行为没有改变。以下是更详细的Hystrix异常：

Caused by: com.netflix.hystrix.exception.HystrixRuntimeException: service-id timed-out and no fallback available.
    at com.netflix.hystrix.AbstractCommand$16.call(AbstractCommand.java:806) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.AbstractCommand$16.call(AbstractCommand.java:790) ~[hystrix-core-1.4.23.jar:1.4.23]
    at rx.internal.operators.OperatorOnErrorResumeNextViaFunction$1.onError(OperatorOnErrorResumeNextViaFunction.java:99) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.internal.operators.OperatorDoOnEach$1.onError(OperatorDoOnEach.java:70) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.internal.operators.OperatorDoOnEach$1.onError(OperatorDoOnEach.java:70) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.internal.operators.OperatorDoOnEach$1.onError(OperatorDoOnEach.java:70) ~[rxjava-1.0.14.jar:1.0.14]
    at com.netflix.hystrix.AbstractCommand$DeprecatedOnFallbackHookApplication$1.onError(AbstractCommand.java:1521) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.AbstractCommand$FallbackHookApplication$1.onError(AbstractCommand.java:1411) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.HystrixCommand$2.call(HystrixCommand.java:314) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.HystrixCommand$2.call(HystrixCommand.java:306) ~[hystrix-core-1.4.23.jar:1.4.23]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:162) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable$2.call(Observable.java:154) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.Observable.unsafeSubscribe(Observable.java:7710) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.internal.operators.OperatorOnErrorResumeNextViaFunction$1.onError(OperatorOnErrorResumeNextViaFunction.java:100) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.internal.operators.OperatorDoOnEach$1.onError(OperatorDoOnEach.java:70) ~[rxjava-1.0.14.jar:1.0.14]
    at rx.internal.operators.OperatorDoOnEach$1.onError(OperatorDoOnEach.java:70) ~[rxjava-1.0.14.jar:1.0.14]
    at com.netflix.hystrix.AbstractCommand$HystrixObservableTimeoutOperator$1.run(AbstractCommand.java:958) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.strategy.concurrency.HystrixContextRunnable$1.call(HystrixContextRunnable.java:41) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.strategy.concurrency.HystrixContextRunnable$1.call(HystrixContextRunnable.java:37) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.strategy.concurrency.HystrixContextRunnable.run(HystrixContextRunnable.java:57) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.AbstractCommand$HystrixObservableTimeoutOperator$2.tick(AbstractCommand.java:978) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.util.HystrixTimer$1.run(HystrixTimer.java:100) ~[hystrix-core-1.4.23.jar:1.4.23]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[na:1.8.0_66]
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) ~[na:1.8.0_66]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) ~[na:1.8.0_66]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) ~[na:1.8.0_66]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_66]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_66]
    ... 1 common frames omitted

Caused by: java.util.concurrent.TimeoutException: null
    at com.netflix.hystrix.AbstractCommand$9.call(AbstractCommand.java:601) ~[hystrix-core-1.4.23.jar:1.4.23]
    at com.netflix.hystrix.AbstractCommand$9.call(AbstractCommand.java:581) ~[hystrix-core-1.4.23.jar:1.4.23]
    at rx.internal.operators.OperatorOnErrorResumeNextViaFunction$1.onError(OperatorOnErrorResumeNextViaFunction.java:99) ~[rxjava-1.0.14.jar:1.0.14]
    ... 15 common frames omitted

Answer 1

我也有同样的问题。这就给我解决了：

关于本文，只有当http客户端设置为ribbon的RestClient时，ribbon才会恢复。默认情况下，功能区使用Apache http客户端，它不会重试任何请求。

由于Ribbon的restclient被弃用，您应该考虑使用spring-retry（https://github.com/spring-projects/spring-retry）

请记住，在Ribbon上配置重试时，您还必须处理zuul的hystrix超时。