上一篇我们介绍了使用 Hystrix Dashboard 来展示 Hystrix 用于熔断的各项度量指标。通过 Hystrix Dashboard,我们可以方便的查看服务实例的综合情况,比如:服务调用次数、服务调用延迟等。但是仅通过 Hystrix Dashboard 我们只能实现对服务当个实例的数据展现,在生产环境我们的服务是肯定需要做高可用的,那么对于多实例的情况,我们就需要将这些度量指标数据进行聚合。下面,在本篇中,我们就来介绍一下另外一个工具:Turbine。
准备工作
在开始使用 Turbine 之前,我们先回顾一下上一篇中实现的架构,如下图所示:
其中,我们构建的内容包括:
- eureka-server:服务注册中心
- eureka-producer:服务提供者
- eureka-consumer-hystrix:使用 Feign 和 Hystrix 实现的服务消费者
- hystrix-dashboard:用于展示
eureka-consumer-hystrix
服务的 Hystrix 数据
创建 Turbine
下面,我们将在上述架构基础上,引入 Turbine 来对服务的 Hystrix 数据进行聚合展示。 这里我们将分别介绍两种聚合方式。
通过 HTTP 收集聚合
创建一个标准的 Spring Boot 工程,命名为:turbine。
POM 配置
在 pom.xml 中添加以下依赖
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<dependency>
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启动类
在启动类上使用@EnableTurbine
注解开启 Turbine
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配置文件
在 application.yml 加入 Eureka 和 Turbine 的相关配置
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spring:
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参数说明
turbine.app-config
参数指定了需要收集监控信息的服务名;turbine.cluster-name-expression
参数指定了集群名称为default
,当我们服务数量非常多的时候,可以启动多个 Turbine 服务来构建不同的聚合集群,而该参数可以用来区分这些不同的聚合集群,同时该参数值可以在 Hystrix 仪表盘中用来定位不同的聚合集群,只需要在 Hystrix Stream 的 URL 中通过 cluster 参数来指定;turbine.combine-host-port
参数设置为true
,可以让同一主机上的服务通过主机名与端口号的组合来进行区分,默认情况下会以 host 来区分不同的服务,这会使得在本地调试的时候,本机上的不同服务聚合成一个服务来统计。
注意:new String("default")
这个一定要用 String 来包一下,否则启动的时候会抛出异常:
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org.springframework.expression.spel.SpelEvaluationException: EL1008E: Property or field ‘default‘ cannot be found on object of type ‘com.netflix.appinfo.InstanceInfo‘ - maybe not public or not valid?
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测试
在完成了上面的内容构建之后,我们来体验一下 Turbine 对集群的监控能力。分别启动
- eureka-server
- eureka-producer
- eureka-consumer-hystrix
- turbine
- hystrix-dashboard
访问 Hystrix Dashboard 并开启对 http://localhost:12010/turbine.stream 的监控,这时候,我们将看到针对服务 eureka-consumer-hystrix
的聚合监控数据。
通过消息代理收集聚合
Spring Cloud 在封装 Turbine 的时候,还实现了基于消息代理的收集实现。所以,我们可以将所有需要收集的监控信息都输出到消息代理中,然后 Turbine 服务再从消息代理中异步的获取这些监控信息,最后将这些监控信息聚合并输出到 Hystrix Dashboard 中。通过引入消息代理,我们的 Turbine 和 Hystrix Dashoard 实现的监控架构可以改成如下图所示的结构:
从图中我们可以看到,这里多了一个重要元素:RabbitMQ。对于 RabbitMQ 的安装与基本时候我们可以查看之前的 MQ 系列,这里不做过多的说明。下面,我们可以来构建一个新的应用来实现基于消息代理的 Turbine 聚合服务。
关于通过 MQ 的聚合,在 Finchley.RC1 版本下有好多坑,好在最后能正常运行了。
Turbine Stream
创建一个标准的 Spring Boot 工程,命名为:turbine-amqp
POM
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<dependency>
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配置文件
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spring:
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启动类
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改造服务调用者
以之前的 eureka-consumer-hystrix 项目为基础,在 pom.xml 里加入以下依赖
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<dependency>
|
再在启动类上加上@EnableHystrix
注解
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测试
分别启动 eureka-consumer-hystrix、turbine-amqp 这两个项目,然后在 RabbitMQ 的管理后台可以看到,自动创建了一个 Exchange 和 Queue
看到这还是挺高兴的,但是……
当访问了一下 consumer 中的接口后,就开始了艰辛的爬坑路程……
遇到的坑
依赖
这个 Turbine Stream 之前应该是叫 Turbine AMQP,当时有个 spring-cloud-starter-turbine-amqp 依赖可以用,里边包装了相关的依赖,但是现在它被 deprecated 了,让用 spring-cloud-starter-netflix-turbine-stream 来代替,这就得靠自己来组合了。而坑主要就出在这里,至于哪些是必须的,哪些是添加了后就出问题的,还有依赖冲突的问题,都得靠自己来搞了。
JsonParseException
Turbine Stream 从 RabbitMQ 取数据的时候抛出以下异常:
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com.fasterxml.jackson.core.JsonParseException: Unexpected character (‘,‘ (code 44)): Expected space separating root-level values
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实际的 json 串类似以下格式:
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{"origin":{"host":"172.16.106.93","port":9013,"serviceId":"eureka-consumer-hystrix","id":"application-1"},"event":"message","data":{"type":"HystrixCommand","name":"eureka-consumer-hystrix.HelloRemote#hello(String)","group":"eureka-producer","currentTime":1523938311789,"isCircuitBreakerOpen":false,"errorPercentage":0,"errorCount":0,"requestCount":0,"rollingCountCollapsedRequests":0,"rollingCountExceptionsThrown":0,"rollingCountFailure":0,"rollingCountFallbackFailure":0,"rollingCountFallbackRejection":0,"rollingCountFallbackSuccess":0,"rollingCountResponsesFromCache":0,"rollingCountSemaphoreRejected":0,"rollingCountShortCircuited":0,"rollingCountSuccess":0,"rollingCountThreadPoolRejected":0,"rollingCountTimeout":0,"currentConcurrentExecutionCount":1,"latencyExecute_mean":0,"latencyExecute":{"0":0,"25":0,"50":0,"75":0,"90":0,"95":0,"99":0,"99.5":0,"100":0},"latencyTotal_mean":0,"latencyTotal":{"0":0,"25":0,"50":0,"75":0,"90":0,"95":0,"99":0,"99.5":0,"100":0},"propertyValue_circuitBreakerRequestVolumeThreshold":20,"propertyValue_circuitBreakerSleepWindowInMilliseconds":5000,"propertyValue_circuitBreakerErrorThresholdPercentage":50,"propertyValue_circuitBreakerForceOpen":false,"propertyValue_circuitBreakerForceClosed":false,"propertyValue_circuitBreakerEnabled":true,"propertyValue_executionIsolationStrategy":"THREAD","propertyValue_executionIsolationThreadTimeoutInMilliseconds":1000,"propertyValue_executionIsolationThreadInterruptOnTimeout":true,"propertyValue_executionIsolationThreadPoolKeyOverride":null,"propertyValue_executionIsolationSemaphoreMaxConcurrentRequests":10,"propertyValue_fallbackIsolationSemaphoreMaxConcurrentRequests":10,"propertyValue_metricsRollingStatisticalWindowInMilliseconds":10000,"propertyValue_requestCacheEnabled":true,"propertyValue_requestLogEnabled":true,"reportingHosts":1}}
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上边这串字符串转为 byte[] 后就是
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123,34,111,114,105,103,105,110,34,58,123,34,104,111,115,116,34,58,34,49,55,50,46,49,54,46,49,48,54,46,57,51,34,44,34,112,111,114,116,34,58,57,48,49,51,44,34,115,101,114,118,105,99,101,73,100,34,58,34,101,117,114,101,107,97,45,99,111,110,115,117,109,101,114,45,104,121,115,116,114,105,120,34,44,34,105,100,34,58,34,97,112,112,108,105,99,97,116,105,111,110,45,49,34,125,44,34,101,118,101,110,116,34,58,34,109,101,115,115,97,103,101,34,44,34,100,97,116,97,34,58,123,34,116,121,112,101,34,58,34,72,121,115,116,114,105,120,67,111,109,109,97,110,100,34,44,34,110,97,109,101,34,58,34,101,117,114,101,107,97,45,99,111,110,115,117,109,101,114,45,104,121,115,116,114,105,120,46,72,101,108,108,111,82,101,109,111,116,101,35,104,101,108,108,111,40,83,116,114,105,110,103,41,34,44,34,103,114,111,117,112,34,58,34,101,117,114,101,107,97,45,112,114,111,100,117,99,101,114,34,44,34,99,117,114,114,101,110,116,84,105,109,101,34,58,49,53,50,51,57,51,56,56,57,49,55,53,48,44,34,105,115,67,105,114,99,117,105,116,66,114,101,97,107,101,114,79,112,101,110,34,58,102,97,108,115,101,44,34,101,114,114,111,114,80,101,114,99,101,110,116,97,103,101,34,58,48,44,34,101,114,114,111,114,67,111,117,110,116,34,58,48,44,34,114,101,113,117,101,115,116,67,111,117,110,116,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,67,111,108,108,97,112,115,101,100,82,101,113,117,101,115,116,115,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,69,120,99,101,112,116,105,111,110,115,84,104,114,111,119,110,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,70,97,105,108,117,114,101,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,70,97,108,108,98,97,99,107,70,97,105,108,117,114,101,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,70,97,108,108,98,97,99,107,82,101,106,101,99,116,105,111,110,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,70,97,108,108,98,97,99,107,83,117,99,99,101,115,115,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,82,101,115,112,111,110,115,101,115,70,114,111,109,67,97,99,104,101,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,83,101,109,97,112,104,111,114,101,82,101,106,101,99,116,101,100,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,83,104,111,114,116,67,105,114,99,117,105,116,101,100,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,83,117,99,99,101,115,115,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,84,104,114,101,97,100,80,111,111,108,82,101,106,101,99,116,101,100,34,58,48,44,34,114,111,108,108,105,110,103,67,111,117,110,116,84,105,109,101,111,117,116,34,58,48,44,34,99,117,114,114,101,110,116,67,111,110,99,117,114,114,101,110,116,69,120,101,99,117,116,105,111,110,67,111,117,110,116,34,58,49,44,34,108,97,116,101,110,99,121,69,120,101,99,117,116,101,95,109,101,97,110,34,58,48,44,34,108,97,116,101,110,99,121,69,120,101,99,117,116,101,34,58,123,34,48,34,58,48,44,34,50,53,34,58,48,44,34,53,48,34,58,48,44,34,55,53,34,58,48,44,34,57,48,34,58,48,44,34,57,53,34,58,48,44,34,57,57,34,58,48,44,34,57,57,46,53,34,58,48,44,34,49,48,48,34,58,48,125,44,34,108,97,116,101,110,99,121,84,111,116,97,108,95,109,101,97,110,34,58,48,44,34,108,97,116,101,110,99,121,84,111,116,97,108,34,58,123,34,48,34,58,48,44,34,50,53,34,58,48,44,34,53,48,34,58,48,44,34,55,53,34,58,48,44,34,57,48,34,58,48,44,34,57,53,34,58,48,44,34,57,57,34,58,48,44,34,57,57,46,53,34,58,48,44,34,49,48,48,34,58,48,125,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,99,105,114,99,117,105,116,66,114,101,97,107,101,114,82,101,113,117,101,115,116,86,111,108,117,109,101,84,104,114,101,115,104,111,108,100,34,58,50,48,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,99,105,114,99,117,105,116,66,114,101,97,107,101,114,83,108,101,101,112,87,105,110,100,111,119,73,110,77,105,108,108,105,115,101,99,111,110,100,115,34,58,53,48,48,48,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,99,105,114,99,117,105,116,66,114,101,97,107,101,114,69,114,114,111,114,84,104,114,101,115,104,111,108,100,80,101,114,99,101,110,116,97,103,101,34,58,53,48,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,99,105,114,99,117,105,116,66,114,101,97,107,101,114,70,111,114,99,101,79,112,101,110,34,58,102,97,108,115,101,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,99,105,114,99,117,105,116,66,114,101,97,107,101,114,70,111,114,99,101,67,108,111,115,101,100,34,58,102,97,108,115,101,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,99,105,114,99,117,105,116,66,114,101,97,107,101,114,69,110,97,98,108,101,100,34,58,116,114,117,101,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,101,120,101,99,117,116,105,111,110,73,115,111,108,97,116,105,111,110,83,116,114,97,116,101,103,121,34,58,34,84,72,82,69,65,68,34,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,101,120,101,99,117,116,105,111,110,73,115,111,108,97,116,105,111,110,84,104,114,101,97,100,84,105,109,101,111,117,116,73,110,77,105,108,108,105,115,101,99,111,110,100,115,34,58,49,48,48,48,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,101,120,101,99,117,116,105,111,110,73,115,111,108,97,116,105,111,110,84,104,114,101,97,100,73,110,116,101,114,114,117,112,116,79,110,84,105,109,101,111,117,116,34,58,116,114,117,101,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,101,120,101,99,117,116,105,111,110,73,115,111,108,97,116,105,111,110,84,104,114,101,97,100,80,111,111,108,75,101,121,79,118,101,114,114,105,100,101,34,58,110,117,108,108,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,101,120,101,99,117,116,105,111,110,73,115,111,108,97,116,105,111,110,83,101,109,97,112,104,111,114,101,77,97,120,67,111,110,99,117,114,114,101,110,116,82,101,113,117,101,115,116,115,34,58,49,48,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,102,97,108,108,98,97,99,107,73,115,111,108,97,116,105,111,110,83,101,109,97,112,104,111,114,101,77,97,120,67,111,110,99,117,114,114,101,110,116,82,101,113,117,101,115,116,115,34,58,49,48,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,109,101,116,114,105,99,115,82,111,108,108,105,110,103,83,116,97,116,105,115,116,105,99,97,108,87,105,110,100,111,119,73,110,77,105,108,108,105,115,101,99,111,110,100,115,34,58,49,48,48,48,48,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,114,101,113,117,101,115,116,67,97,99,104,101,69,110,97,98,108,101,100,34,58,116,114,117,101,44,34,112,114,111,112,101,114,116,121,86,97,108,117,101,95,114,101,113,117,101,115,116,76,111,103,69,110,97,98,108,101,100,34,58,116,114,117,101,44,34,114,101,112,111,114,116,105,110,103,72,111,115,116,115,34,58,49,125,125
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从上边异常可以看出,这其实就是将这个 byte[] 转为 String 的时候出错了。
在源码里找了好久,最后发现原来是启动的时候要初始化一个 ConfigurableCompositeMessageConverter
,但是这个类默认的只提供以下 4 个MessageConverter
:
- MappingJackson2MessageConverter
- ByteArrayMessageConverter
- ObjectStringMessageConverter
- GenericMessageConverter
这 4 个 Converter 处理 byte[] -> String 的时候都会出问题(上边的异常就是MappingJackson2MessageConverter
这个抛出的)。说到这你可能会问了,byte[] 转 String 有这么难吗?不就一个 new String(bytes) 就解决了。我也这么想啊,就差自己动手写了。
这时候发现了CompositeMessageConverterFactory
,从名字上可以看出就是 MessageConverter
的工厂类,似乎是一根救命稻草。它里边默认提供了 7 个 Converter,第一个就是ApplicationJsonMessageMarshallingConverter
,看了里边的实现,这不正是我需要的嘛!
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if (message.getPayload() instanceof byte[] && targetClass.isAssignableFrom(String.class)) {
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所以就自己手动注入这个 bean
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其实这个 Bean 在
ContentTypeConfiguration
中已经声明了但没效果,我只是原封不动的 copy 出来。
1
2
3
4
Fatal Exception thrown on Scheduler.Worker thread
这个的异常信息如下:
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Exception in thread "RxComputationScheduler-1" java.lang.IllegalStateException: Fatal Exception thrown on Scheduler.Worker thread.
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同时在 Hystrix Dashboard 中 monitor 相应的地址的会提示 “Unable to connect to Command Metric Stream.” 并在 Console 里报错:
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EventSource‘s response has a MIME type ("text/plain") that is not "text/event-stream". Aborting the connection.
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这个问题真不知道怎么搞了,先弃坑了,有空了再研究吧。
2018-05-06 更新:
这个问题可以详见 Github 上的 这个 issus 感谢 @MadeInChina
为了本文的完整性,我这里也说明下这个问题的解决思路和解决办法。
这个异常信息关键的一行是是第 22 行
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at org.springframework.cloud.netflix.turbine.stream.TurbineStreamConfiguration.lambda$null$6(TurbineStreamConfiguration.java:106)
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我们就打开 TurbineStreamConfiguration 看一下这 106 行到底写了点啥
如果这时你点进去看 ServerSentEvent 这个类,问题其实就明了了(我当时就是困在了response.writeAndFlush
这个方法上,根本没注意到 ServerSentEvent)
这个类直接报错,因为没有完整实现 ByteBufHolder 里边的方法,从这你已经能看出来应该是相关依赖的问题了。我们这里注意一下这个类所在的 JAR 包 io.reactivex:rxnetty:0.4.9
,然后再看一下它实现的这个接口
这个接口的变更记录可以看这里。最后一次的修改是在 2016.5.17 添加了几个方法,也就是说 ByteBufHolder 在io.netty:netty-buffer:4.1.0.Final
(2016.5.25)就已经被修改了,更不用说io.netty:netty-buffer:4.1.23.Final
(2018.4.4)了。而io.reactivex:rxnetty:0.4.9
是一个 2015.5.6 发布的 jar 包。
那我们就用io.reactivex:rxnetty:0.4.20
最新的版本来试试,pom.xml 里添加以下内容
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<dependency>
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再次启动并测试
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$ curl http://localhost:8989
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发现依旧报错,控制台里错误如下
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2018-05-06 23:29:37.056 WARN 52477 --- [o-eventloop-3-2] i.n.c.AbstractChannelHandlerContext : An exception ‘{}‘ [enable DEBUG level for full stacktrace] was thrown by a user handler‘s exceptionCaught() method while handling the following exception:
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就仅看异常栈的第一行,你会发现 UnicastContentSubject 这个类在当前环境下有三个
将三个都打开来看一下,会发现io.reactivex:rxnetty
那两个看起来问题不大,而com.netflix.rxnetty:rx-netty
这个直接又是报错,依旧是未完全实现接口。
根据 DEBUG 的信息来看,而实际使用的就是com.netflix.rxnetty:rx-netty:0.3.18
里边的这个,那就分析一下依赖吧,把这个残疾的老古董(2014.11.6)给排除掉
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$ mvn dependency:tree -Dverbose -Dincludes=*:*netty*
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最终 pom.xml 里的依赖坐标如下(这也是能正常启动 Turbine Stream 的最小配置了,Spring Cloud 的版本为 Finchley.RC1):
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<dependency>
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再次测试就能正常收到 SSE 了
1
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$ curl http://localhost:8989
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控制台也不报错了
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2018-05-06 23:57:25.833 INFO 53309 --- [o-eventloop-3-1] o.s.c.n.t.s.TurbineStreamConfiguration : SSE Request Received
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然后在 Hystrix Dashboard 的地址栏里输入 http://localhost:8989 就能看到了(/turbine.stream
可加可不加,如果要修改端口号,在 Spring Boot 的配置文件中修改 turbine.stream.port
)
相关阅读
Spring Cloud(一):服务治理技术概览
Spring Cloud(二):服务注册与发现 Eureka
Spring Cloud(三):服务提供与调用 Eureka
Spring Cloud(四):服务容错保护 Hystrix
Spring Cloud(五):Hystrix 监控面板
Spring Cloud(六):Hystrix 监控数据聚合 Turbine
Spring Cloud(七):配置中心(Git 版与动态刷新)
Spring Cloud(八):配置中心(服务化与高可用)
Spring Cloud(九):配置中心(消息总线)
Spring Cloud(十):服务网关 Zuul(路由)
Spring Cloud(十一):服务网关 Zuul(过滤器)
Spring Cloud(十二):分布式链路跟踪(Sleuth 与 Zipkin)
示例代码:GitHub
参考
Spring Cloud 构建微服务架构:Hystrix 监控数据聚合【Dalston 版】
springcloud(五):熔断监控 Hystrix Dashboard 和 Turbine
Turbine AMQP aggregator fails to de-serialize messages from Hystrix stream
Spring Cloud - Turbine Stream