diff --git a/README.md b/README.md index 4a3706b..c855886 100644 --- a/README.md +++ b/README.md @@ -64,21 +64,20 @@ spring-cloud:Finchley.SR2
-## 3. spring-cloud samples +## 3. spring-cloud samples -| samples | 描述 | 官方文档 | -| ------------------------------------------------------------ | --------------------------------- | ------------------------------------------------------------ | -| [spring-cloud-Eureka](https://github.com/heibaiying/spring-samples-for-all/tree/master/spring-cloud/spring-cloud-eureka) | 服务的注册和发现 | [Service Discovery: Eureka Clients](https://cloud.spring.io/spring-cloud-static/spring-cloud-netflix/2.1.0.RC3/single/spring-cloud-netflix.html#_service_discovery_eureka_clients) | -| [spring-cloud-Eureka-cluster](https://github.com/heibaiying/spring-samples-for-all/tree/master/spring-cloud/spring-cloud-eureka-cluster) | eureka 高可用集群搭建 | | -| spring-cloud-Ribbon | 客户端负载均衡 | | -| spring-cloud-OpenFeign | 声明式服务调用 | [Spring Cloud OpenFeign 官方文档](https://spring.io/projects/spring-cloud-openfeign#learn) | -| spring-cloud-Hystrix | 服务容错与降级保护 | | -| spring-cloud-config | 分布式配置中心 | [Spring Cloud Config](https://spring.io/projects/spring-cloud-config#learn) | -| spring-cloud-stream | spring cloud 对消息服务的抽象整合 | [spring-cloud-stream官方文档](https://cloud.spring.io/spring-cloud-stream/) | -| spring-cloud-zuul | spring cloud 网关服务 | [Router and Filter: Zuul](http://projects.spring.io/spring-cloud/spring-cloud.html#_router_and_filter_zuul) | -| spring-cloud-sleuth-Zipkin | 分布式服务追踪 | [Spring Cloud Sleuth](https://spring.io/projects/spring-cloud-sleuth#learn) | -| spring-cloud-config | 分布式配置中心 | [Spring Cloud Config](https://spring.io/projects/spring-cloud-config#learn) | -| spring-cloud -bus | spring cloud 消息总线 | | +| samples | 描述 | 官方文档 | +| ------------------------------------------------------------ | ---------------------------------- | ------------------------------------------------------------ | +| spring-cloud | 微服务简介与用例说明 | | +| [spring-cloud-Eureka](https://github.com/heibaiying/spring-samples-for-all/tree/master/spring-cloud/spring-cloud-eureka) | 服务的注册和发现 | [Service Discovery: Eureka Clients](https://cloud.spring.io/spring-cloud-static/spring-cloud-netflix/2.1.0.RC3/single/spring-cloud-netflix.html#_service_discovery_eureka_clients) | +| [spring-cloud-Eureka-cluster](https://github.com/heibaiying/spring-samples-for-all/tree/master/spring-cloud/spring-cloud-eureka-cluster) | eureka 高可用集群搭建 | | +| spring-cloud-Ribbon | RestTemplate的使用、客户端负载均衡 | [ribbon](http://cloud.spring.io/spring-cloud-netflix/multi/multi_spring-cloud-ribbon.html) | +| spring-cloud-OpenFeign | 声明式服务调用 | [Spring Cloud OpenFeign 官方文档](https://spring.io/projects/spring-cloud-openfeign#learn) | +| spring-cloud-Hystrix | 熔断器 | | +| spring-cloud-zuul | 网关服务 | [Router and Filter: Zuul](http://projects.spring.io/spring-cloud/spring-cloud.html#_router_and_filter_zuul) | +| spring-cloud-sleuth-Zipkin | 分布式系统服务追踪 | [Spring Cloud Sleuth](https://spring.io/projects/spring-cloud-sleuth#learn) | +| spring-cloud-config-bus | 配置中心 + 消息总线实现配置热更新 | [Spring Cloud Config](https://spring.io/projects/spring-cloud-config#learn) | +| spring-cloud-stream | spring cloud 对消息服务的抽象整合 | [spring-cloud-stream官方文档](https://cloud.spring.io/spring-cloud-stream/) |
diff --git a/pictures/ribbon-consumer.png b/pictures/ribbon-consumer.png new file mode 100644 index 0000000..5c4c558 Binary files /dev/null and b/pictures/ribbon-consumer.png differ diff --git a/pictures/ribbon-producer.png b/pictures/ribbon-producer.png new file mode 100644 index 0000000..b46fda6 Binary files /dev/null and b/pictures/ribbon-producer.png differ diff --git a/pictures/spring-cloud-ribbon.png b/pictures/spring-cloud-ribbon.png new file mode 100644 index 0000000..d874c71 Binary files /dev/null and b/pictures/spring-cloud-ribbon.png differ diff --git a/spring-cloud/spring-cloud-ribbon/README.md b/spring-cloud/spring-cloud-ribbon/README.md new file mode 100644 index 0000000..b748975 --- /dev/null +++ b/spring-cloud/spring-cloud-ribbon/README.md @@ -0,0 +1,282 @@ +# spring-cloud-ribbon + +## 一、ribbon 简介 + +ribbon是Netfix公司开源的负载均衡组件,采用服务端负载均衡的方式,即消费者客户端维护可用的服务列表,并通过负载均衡的方式将请求按照指定的策略分摊给消费者,从而达到负载均衡的方式。 + + + +## 二、项目结构 + ++ common: 公共的接口和实体类; ++ consumer: 服务的消费者,采用RestTemplate调用产品服务; ++ producer:服务的提供者; ++ eureka: 注册中心,ribbon 从注册中心获取可用的服务列表,是实现负载均衡的基础。这里使用我们在[服务的注册与发现](https://github.com/heibaiying/spring-samples-for-all/tree/master/spring-cloud/spring-cloud-eureka)这个用例中搭建的简单注册中心作为测试即可。 + +
+ + + +## 三、服务提供者的实现 + +#### 3.1 产品服务由`ProductService`提供,并通过`ProducerController`将服务暴露给外部调用。 + +
+ +ProductService.java: + +```java +/** + * @author : heibaiying + * @description : 产品提供接口实现类 + * 这里为了之后直观的看到负载均衡的结果,我们继承了 ApplicationListener,从 WebServerInitializedEvent 获取服务的端口号,并拼接在产品名称上 + */ +@Service +public class ProductService implements IProductService, ApplicationListener { + + private static List productList = new ArrayList<>(); + + public Product queryProductById(int id) { + for (Product product : productList) { + if (product.getId() == id) { + return product; + } + } + return null; + } + + public List queryAllProducts() { + return productList; + } + + @Override + public void saveProduct(Product product) { + productList.add(product); + } + + @Override + public void onApplicationEvent(WebServerInitializedEvent event) { + int port = event.getWebServer().getPort(); + for (long i = 0; i < 20; i++) { + productList.add(new Product(i, port + "产品" + i, i / 2 == 0, new Date(), 66.66f * i)); + } + } +} +``` + +ProducerController.java: + +```java +@RestController +public class ProducerController { + + @Autowired + private IProductService productService; + + @GetMapping("products") + public List productList() { + return productService.queryAllProducts(); + } + + @GetMapping("product/{id}") + public Product productDetail(@PathVariable int id) { + return productService.queryProductById(id); + } + + @PostMapping("product") + public void save(@RequestBody Product product) { + productService.saveProduct(product); + } +} +``` + +#### 3.2 将服务注册到注册中心 + +```java +server: + port: 8020 +# 指定服务命名 +spring: + application: + name: producer +# 指定注册中心地址 +eureka: + client: + serviceUrl: + defaultZone: http://localhost:8010/eureka/ +``` + + + +## 四、服务消费者的实现 + +
+ +#### 4.1 导入负载均衡需要的依赖 + +```xml + + + org.springframework.cloud + spring-cloud-starter-netflix-ribbon + +``` + +#### 4.2 指定注册中心的地址 + +```java +server: + port: 8080 +# 指定服务命名 +spring: + application: + name: consumer +# 指定注册中心地址 +eureka: + client: + serviceUrl: + defaultZone: http://localhost:8010/eureka/ +``` + +#### 4.3 使用@LoadBalanced配置RestTemplate即可实现客户端负载均衡 + +```java +import org.springframework.cloud.client.loadbalancer.LoadBalanced; +import org.springframework.context.annotation.Bean; +import org.springframework.context.annotation.Configuration; +import org.springframework.web.client.RestTemplate; + +@Configuration +public class RibbonConfig { + + @LoadBalanced // 配置客户端负载均衡 + @Bean + public RestTemplate restTemplate() { + return new RestTemplate(); + } +} +``` + +#### 4.4 使用RestTemplate调用远程服务 + +这里我们在调用远程服务的时候,url填写的是服务名+具体接口地址 ,由于我们的同一个服务会存在多个实例,在使用@LoadBalanced配置RestTemplate调用服务时,客户端就会从按照指定的负载均衡的方式将请求分摊到多个实例上。(默认的负载均衡采用的是RoundRobinRule(轮询)的策略,有特殊需求时候可以采用其他内置的策略规则,或者实现IRule来定义自己的负载均衡策略)。 + +```java +@Service +public class ProductService implements IProductService { + + @Autowired + private RestTemplate restTemplate; + + public Product queryProductById(int id) { + ResponseEntity responseEntity = restTemplate.getForEntity("http://producer/product/{1}", Product.class, id); + return responseEntity.getBody(); + } + + + public List queryAllProducts() { + ResponseEntity responseEntity = restTemplate.getForEntity("http://producer/products", List.class); + List productList = responseEntity.getBody(); + return productList; + } + + public void saveProduct(Product product) { + restTemplate.postForObject("http://producer/product", product, Void.class); + } +} + +``` + + + +## 五、启动测试 + +#### 5.1 启动一个Eureka服务、三个producer服务(注意区分端口)、和一个消费者服务 + +
+ +**服务注册中心:** + +
+ +#### 5.2 访问http://localhost:8080/sell/products 查看负载均衡的调用结果 + +
+ +
+ +## 六、 附1: 关于RestTemplate的说明 + +#### 6.1 restTemplate 调用对应resultful接口时候,使用的方法应该与接口声明方式(@GetMapping、@PostMapping、@PutMapping、@DeleteMapping)保持一致。请求类型与对应的调用方法如下。 + +- GET请求(getForObject 、getForEntity) +- POST请求(postForObject 、postForEntity) +- PUT请求(put) +- DELETE请求 (delete) + +#### 6.2 ForEntity()和ForObject的区别 + +- `ForEntity()`发送一个请求,返回的ResponseEntity包含了响应体所映射成的对象 + +- `ForObject()`发送一个请求,返回的请求体将映射为一个对象 + +例如: + +```java +ResponseEntity responseEntity = restTemplate.getForEntity("http://producer/product/{1}", Product.class, id); + Product product = restTemplate.getForObject("http://producer/product/{1}", Product.class, id); +``` + + + +## 七、 附2: 关于ribbon更多负载均衡的策略 + +Ribbon内置了多种负载均衡策略,如果有更复杂的需求,可以自己实现IRule。 + +#### 7.1 内置的负载均衡的策略如下图 + +![Ribbon负载均衡策略.png](http://upload-images.jianshu.io/upload_images/6944619-0355d316f5df9b3f.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240) + +图片来源于博客:[Ribbon负载均衡策略与自定义配置](https://blog.csdn.net/jrn1012/article/details/77837680) + + + +#### 7.2 配置文件指定负载均衡的方式 + +要设置`IRule`名为的服务名称`users`,您可以设置以下属性: + +```yaml +users: + ribbon: + NFLoadBalancerRuleClassName: com.netflix.loadbalancer.WeightedResponseTimeRule +``` + + + +#### 7.3 代码指定负载均衡的方式 + +```java +@Configuration +@RibbonClient(name = "custom", configuration = CustomConfiguration.class) +public class TestConfiguration { +} +``` + +```java +@Configuration +public class CustomConfiguration { + + @Bean + public IRule ribbonRule() { + return new BestAvailableRule(); + } +} +``` + +在使用代码方式的时候需要注意 [官方文档](http://cloud.spring.io/spring-cloud-netflix/multi/multi_spring-cloud-ribbon.html#_customizing_the_ribbon_client)中关于注解方式有以下强调: + +```properties +The CustomConfiguration clas must be a @Configuration class, but take care that it is not in a @ComponentScan for the main application context. Otherwise, it is shared by all the @RibbonClients. If you use @ComponentScan (or @SpringBootApplication), you need to take steps to avoid it being included (for instance, you can put it in a separate, non-overlapping package or specify the packages to scan explicitly in the @ComponentScan). +``` + +该`CustomConfiguration`类必须是`@Configuration`标注的,但需要注意的它不是在`@ComponentScan`主应用程序上下文。否则,它将由所有`@RibbonClients`共享。如果你使用`@ComponentScan`(或`@SpringBootApplication`),你需要采取一些措施来避免它被扫描到(例如,你可以把它放在一个独立的,非重叠的包,或用`@ComponentScan`时显示扫描指定的包)。 \ No newline at end of file