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Posted to commits@dubbo.apache.org by je...@apache.org on 2018/08/10 08:40:15 UTC
[incubator-dubbo-website] branch asf-site updated: add blog
This is an automated email from the ASF dual-hosted git repository.
jerrick pushed a commit to branch asf-site
in repository https://gitbox.apache.org/repos/asf/incubator-dubbo-website.git
The following commit(s) were added to refs/heads/asf-site by this push:
new 7e0e10f add blog
7e0e10f is described below
commit 7e0e10fffb435624bead7df865c8ff5e1eb28483
Author: zhuyong <yo...@alibaba-inc.com>
AuthorDate: Fri Aug 10 16:39:53 2018 +0800
add blog
---
blog/zh-cn/dubbo-integrate-with-hystrix.md | 201 +++++++++++++++++++++
...c3831ea1057a5367.js => 4828dc59b19c927e111e.js} | 4 +-
build/654055e491fb5dea7da2.js | 6 +
build/fca877d6ab8a5dbba7ca.js | 6 -
build/page.js | 2 +-
md_json/blog.json | 4 +
site_config/blog.js | 7 +
7 files changed, 221 insertions(+), 9 deletions(-)
diff --git a/blog/zh-cn/dubbo-integrate-with-hystrix.md b/blog/zh-cn/dubbo-integrate-with-hystrix.md
new file mode 100644
index 0000000..34d9a2b
--- /dev/null
+++ b/blog/zh-cn/dubbo-integrate-with-hystrix.md
@@ -0,0 +1,201 @@
+# Spring应用快速集成Dubbo + Hystrix
+
+## 背景
+
+Hystrix 旨在通过控制那些访问远程系统、服务和第三方库的节点，从而对延迟和故障提供更强大的容错能力。Hystrix具备拥有回退机制和断路器功能的线程和信号隔离，请求缓存和请求打包，以及监控和配置等功能。
+
+Dubbo是Alibaba开源的，目前国内最流行的java rpc框架。
+
+本文介绍在spring应用里，怎么把Dubbo和Hystrix结合起来使用。
+
+- <https://github.com/Netflix/Hystrix>
+- <https://github.com/apache/incubator-dubbo>
+
+## Spring Boot应用
+
+Demo地址： <https://github.com/dubbo/dubbo-samples/tree/master/dubbo-samples-spring-boot-hystrix>
+
+### 生成dubbo集成spring boot的应用
+
+对于不熟悉dubbo 集成spring boot应用的同学，可以在这里直接生成dubbo + spring boot的工程： <http://start.dubbo.io/>
+
+### 配置spring-cloud-starter-netflix-hystrix
+
+spring boot官方提供了对hystrix的集成，直接在pom.xml里加入依赖：
+
+```
+ <dependency>
+ <groupId>org.springframework.cloud</groupId>
+ <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
+ <version>1.4.4.RELEASE</version>
+ </dependency>
+```
+
+然后在Application类上增加`@EnableHystrix`来启用hystrix starter：
+
+```
+@SpringBootApplication
+@EnableHystrix
+public class ProviderApplication {
+```
+
+### 配置Provider端
+
+在Dubbo的Provider上增加`@HystrixCommand`配置，这样子调用就会经过Hystrix代理。
+
+```
+@Service(version = "1.0.0")
+public class HelloServiceImpl implements HelloService {
+ @HystrixCommand(commandProperties = {
+ @HystrixProperty(name = "circuitBreaker.requestVolumeThreshold", value = "10"),
+ @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "2000") })
+ @Override
+ public String sayHello(String name) {
+ // System.out.println("async provider received: " + name);
+ // return "annotation: hello, " + name;
+ throw new RuntimeException("Exception to show hystrix enabled.");
+ }
+}
+```
+
+### 配置Consumer端
+
+对于Consumer端，则可以增加一层method调用，并在method上配置`@HystrixCommand`。当调用出错时，会走到`fallbackMethod = "reliable"`的调用里。
+
+```
+ @Reference(version = "1.0.0")
+ private HelloService demoService;
+
+ @HystrixCommand(fallbackMethod = "reliable")
+ public String doSayHello(String name) {
+ return demoService.sayHello(name);
+ }
+ public String reliable(String name) {
+ return "hystrix fallback value";
+ }
+```
+
+通过上面的配置，很简单地就完成了Spring Boot里Dubbo + Hystrix的集成。
+
+## 传统Spring Annotation应用
+
+Demo地址： <https://github.com/dubbo/dubbo-samples/tree/master/dubbo-samples-spring-hystrix>
+
+传统spring annotation应用的配置其实也很简单，和spring boot应用不同的是：
+
+1. 显式配置Spring AOP支持：`@EnableAspectJAutoProxy`
+2. 显式通过`@Configuration`配置`HystrixCommandAspect` Bean。
+
+```
+ @Configuration
+ @EnableDubbo(scanBasePackages = "com.alibaba.dubbo.samples.annotation.action")
+ @PropertySource("classpath:/spring/dubbo-consumer.properties")
+ @ComponentScan(value = {"com.alibaba.dubbo.samples.annotation.action"})
+ @EnableAspectJAutoProxy
+ static public class ConsumerConfiguration {
+
+ @Bean
+ public HystrixCommandAspect hystrixCommandAspect() {
+ return new HystrixCommandAspect();
+ }
+ }
+```
+
+## Hystrix集成Spring AOP原理
+
+在上面的例子里可以看到，Hystrix对Spring的集成是通过Spring AOP来实现的。下面简单分析下实现。
+
+```
+@Aspect
+public class HystrixCommandAspect {
+ @Pointcut("@annotation(com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand)")
+ public void hystrixCommandAnnotationPointcut() {
+ }
+ @Pointcut("@annotation(com.netflix.hystrix.contrib.javanica.annotation.HystrixCollapser)")
+ public void hystrixCollapserAnnotationPointcut() {
+ }
+
+ @Around("hystrixCommandAnnotationPointcut() || hystrixCollapserAnnotationPointcut()")
+ public Object methodsAnnotatedWithHystrixCommand(final ProceedingJoinPoint joinPoint) throws Throwable {
+ Method method = getMethodFromTarget(joinPoint);
+ Validate.notNull(method, "failed to get method from joinPoint: %s", joinPoint);
+ if (method.isAnnotationPresent(HystrixCommand.class) && method.isAnnotationPresent(HystrixCollapser.class)) {
+ throw new IllegalStateException("method cannot be annotated with HystrixCommand and HystrixCollapser " +
+ "annotations at the same time");
+ }
+ MetaHolderFactory metaHolderFactory = META_HOLDER_FACTORY_MAP.get(HystrixPointcutType.of(method));
+ MetaHolder metaHolder = metaHolderFactory.create(joinPoint);
+ HystrixInvokable invokable = HystrixCommandFactory.getInstance().create(metaHolder);
+ ExecutionType executionType = metaHolder.isCollapserAnnotationPresent() ?
+ metaHolder.getCollapserExecutionType() : metaHolder.getExecutionType();
+
+ Object result;
+ try {
+ if (!metaHolder.isObservable()) {
+ result = CommandExecutor.execute(invokable, executionType, metaHolder);
+ } else {
+ result = executeObservable(invokable, executionType, metaHolder);
+ }
+ } catch (HystrixBadRequestException e) {
+ throw e.getCause() != null ? e.getCause() : e;
+ } catch (HystrixRuntimeException e) {
+ throw hystrixRuntimeExceptionToThrowable(metaHolder, e);
+ }
+ return result;
+ }
+```
+
+1. `HystrixCommandAspect`里定义了两个注解的AspectJ Pointcut：`@HystrixCommand`, `@HystrixCollapser`。所有带这两个注解的spring bean都会经过AOP处理
+2. 在`@Around` AOP处理函数里，可以看到Hystrix会创建出`HystrixInvokable`，再通过`CommandExecutor`来执行
+
+## spring-cloud-starter-netflix-hystrix的代码分析
+
+1. `@EnableHystrix` 引入了`@EnableCircuitBreaker`，`@EnableCircuitBreaker`引入了`EnableCircuitBreakerImportSelector`
+
+ ```
+ @EnableCircuitBreaker
+ public @interface EnableHystrix {
+ }
+
+ @Import(EnableCircuitBreakerImportSelector.class)
+ public @interface EnableCircuitBreaker {
+ }
+ ```
+
+2. `EnableCircuitBreakerImportSelector`继承了`SpringFactoryImportSelector<EnableCircuitBreaker>`，使spring加载`META-INF/spring.factories`里的`EnableCircuitBreaker`声明的配置
+
+ 在`META-INF/spring.factories`里可以找到下面的配置，也就是引入了`HystrixCircuitBreakerConfiguration`。
+
+ ```
+ org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker=\
+ org.springframework.cloud.netflix.hystrix.HystrixCircuitBreakerConfiguration
+ ```
+
+3. 在`HystrixCircuitBreakerConfiguration`里可以发现创建了`HystrixCommandAspect`
+
+ ```
+ @Configuration
+ public class HystrixCircuitBreakerConfiguration {
+
+ @Bean
+ public HystrixCommandAspect hystrixCommandAspect() {
+ return new HystrixCommandAspect();
+ }
+ ```
+
+可见`spring-cloud-starter-netflix-hystrix`实际上也是创建了`HystrixCommandAspect`来集成Hystrix。
+
+另外`spring-cloud-starter-netflix-hystrix`里还有metrics, health, dashboard等集成。
+
+## 总结
+
+- 对于dubbo provider的`@Service`是一个spring bean，直接在上面配置`@HystrixCommand`即可
+- 对于dubbo consumer的`@Reference`，可以通过加一层简单的spring method包装，配置`@HystrixCommand`即可
+- Hystrix本身提供`HystrixCommandAspect`来集成Spring AOP，配置了`@HystrixCommand`和`@HystrixCollapser`的spring method都会被Hystrix处理
+
+## 链接
+
+- <https://github.com/Netflix/Hystrix>
+- <https://github.com/apache/incubator-dubbo>
+- <http://start.dubbo.io/>
+- <https://cloud.spring.io/spring-cloud-netflix/single/spring-cloud-netflix.html#_circuit_breaker_hystrix_clients>
\ No newline at end of file
diff --git a/build/5dfcc3831ea1057a5367.js b/build/4828dc59b19c927e111e.js
similarity index 76%
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rename to build/4828dc59b19c927e111e.js
index b382589..138f84b 100644
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+++ b/build/4828dc59b19c927e111e.js
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Copyright (c) 2017 Jed Watson.
Licensed under the MIT License (MIT), see
http://jedwatson.github.io/classnames
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+ Copyright (c) 2017 Jed Watson.
+ Licensed under the MIT License (MIT), see
+ http://jedwatson.github.io/classnames
+*/
+!function(){"use strict";function e(){for(var n=[],s=0;s<arguments.length;s++){var a=arguments[s];if(a){var t=typeof a;if("string"===t||"number"===t)n.push(a);else if(Array.isArray(a)&&a.length){var l=e.apply(null,a);l&&n.push(l)}else if("object"===t)for(var r in a)o.call(a,r)&&a[r]&&n.push(r)}}return n.join(" ")}var o={}.hasOwnProperty;void 0!==n&&n.exports?(e.default=e,n.exports=e):(a=[],void 0!==(t=function(){return e}.apply(s,a))&&(n.exports=t))}()},function(n,s,e){"use strict";funct [...]
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deleted file mode 100644
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- Copyright (c) 2017 Jed Watson.
- Licensed under the MIT License (MIT), see
- http://jedwatson.github.io/classnames
-*/
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diff --git a/md_json/blog.json b/md_json/blog.json
index 40ba1b7..3808afd 100644
--- a/md_json/blog.json
+++ b/md_json/blog.json
@@ -21,6 +21,10 @@
"__html": "<h1>Dubbo的泛化调用</h1>\n<p>以下几种场景可以考虑使用泛化调用：</p>\n<ul>\n<li>服务测试平台</li>\n<li>API 服务网关</li>\n</ul>\n<p>泛化调用主要用于消费端没有 API 接口的情况；不需要引入接口 jar 包，而是直接通过 GenericService 接口来发起服务调用，参数及返回值中的所有 POJO 均用 <code>Map</code> 表示。泛化调用对于服务端无需关注，按正常服务进行暴露即可。</p>\n<p>下面来看看消费端如何使用泛化调用进行服务调用。</p>\n<h4>通过 Spring XML 配置进行泛化调用</h4>\n<p>在 Spring 配置申明 <code>generic="true"</code>，如：</p>\n<pre><code class=\"language-xml\"><span class=\"hljs-tag\"><<span class=\"hljs-name\">dubbo:reference</s [...]
},
{
+ "filename": "dubbo-integrate-with-hystrix.md",
+ "__html": "<h1>Spring应用快速集成Dubbo + Hystrix</h1>\n<h2>背景</h2>\n<p>Hystrix 旨在通过控制那些访问远程系统、服务和第三方库的节点，从而对延迟和故障提供更强大的容错能力。Hystrix具备拥有回退机制和断路器功能的线程和信号隔离，请求缓存和请求打包，以及监控和配置等功能。</p>\n<p>Dubbo是Alibaba开源的，目前国内最流行的java rpc框架。</p>\n<p>本文介绍在spring应用里，怎么把Dubbo和Hystrix结合起来使用。</p>\n<ul>\n<li><a href=\"https://github.com/Netflix/Hystrix\">https://github.com/Netflix/Hystrix</a></li>\n<li><a href=\"https://github.com/apache/incubator-dubbo\">https://github.com/apache/incubator-dubbo</a></li>\n</ul>\n [...]
+ },
+ {
"filename": "dubbo-invoke.md",
"__html": "<h1>Dubbo 关于同步/异步调用的几种方式</h1>\n<p>我们知道，Dubbo 缺省协议采用单一长连接，底层实现是 Netty 的 NIO 异步通讯机制；基于这种机制，Dubbo 实现了以下几种调用方式：</p>\n<ul>\n<li>同步调用</li>\n<li>异步调用</li>\n<li>参数回调</li>\n<li>事件通知</li>\n</ul>\n<h3>同步调用</h3>\n<p>同步调用是一种阻塞式的调用方式，即 Consumer 端代码一直阻塞等待，直到 Provider 端返回为止；</p>\n<p>通常，一个典型的同步调用过程如下：</p>\n<ol>\n<li>Consumer 业务线程调用远程接口，向 Provider 发送请求，同时当前线程处于<code>阻塞</code>状态；</li>\n<li>Provider 接到 Consumer 的请求后，开始处理请求，将结果返回给 Consumer；</li>\n<li>Consumer 收到结果后，当前线程继续往后执行。</li>\n</ol>\n< [...]
},
diff --git a/site_config/blog.js b/site_config/blog.js
index 9ee1931..04e5a97 100644
--- a/site_config/blog.js
+++ b/site_config/blog.js
@@ -80,6 +80,13 @@ export default {
postsTitle: '所有文章',
list: [
{
+ title: 'Spring应用快速集成Dubbo + Hystrix',
+ author: '@hengyunabc',
+ dateStr: 'August 10th, 2018',
+ desc: '本文介绍在spring应用里，怎么把Dubbo和Hystrix结合起来使用',
+ link: '/blog/dubbo-integrate-with-hystrix.md',
+ },
+ {
title: '如何基于Dubbo实现全异步调用链',
author: '@chickenlj',
dateStr: 'August 10th, 2018',