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1.ribbon 服务消费者
ribbon 提供了负载平衡和重试的性能
1.1 负载平衡
1. 从 eureka 取得地址表
2. 应用多个地址来回调用
3. 拿到一个地址, 应用 RestTemplate 执行近程调用
增加负载平衡
1. 增加 ribbon 依赖(eureka client 中曾经蕴含, 不要反复增加)
2. 增加 @LoadBalance 注解, 对 RestTemplate 进行加强
3. 用 RestTemplate 调用的地址, 改成 service-id(注册核心注册的服务名) rt.getForObject(“http://item-service/{1}”, ……)
1.2ribbon 重试
一种容错形式, 调用近程服务失败 (异样, 超时) 时, 能够主动进行重试调用.
增加重试
1. 增加 spring-retry 依赖
2. 配置重试参数
MaxAutoRtries- 单台服务器的重试次数
MaxAutoRtriesNextServer – 更换服务器的次数
OkToRetryOnAllOperations – 是否对所有类型申请都进行重试,默认只对 get 重试
ConnectTimeout – 和近程服务建设连贯的期待超时时长
ReadTimeout – 建设连贯并发送申请后,期待响应的超时时长
留神: 两个超时时长不能再配置文件中设置, 而是在 java 代码中设置.
2. 代码演示
2.1 新建 ribbon 我的项目
2.2 增加依赖
eureka-client 中曾经蕴含 ribbon 依赖
须要增加 sp01-commons 依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.tedu</groupId>
<artifactId>springcloud-012-ribbon</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springcloud-012-ribbon</name>
<description>Demo project for Spring Cloud</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.SR1</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.tedu</groupId>
<artifactId>sp01-commons</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2.3 配置 application.yml 文件
spring:
application:
name: ribbon
server:
port: 3001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka
2.3 代码设置
创立 RestTemplate 实例
RestTemplate 是用来调用其余微服务的工具类, 封装了近程调用代码, 提供了一组用于近程调用的模板办法, 例如:getForObject() postForObject()等
2.3.1 启动类设置
package com.tedu.sp06;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@EnableDiscoveryClient
@SpringBootApplication
public class Sp06RibbonApplication {
// 创立 RestTemplate 实例,并存入 spring 容器
@Bean
public RestTemplate getRestTemplate() {return new RestTemplate();
}
public static void main(String[] args) {SpringApplication.run(Sp06RibbonApplication.class, args);
}
}
2.3.2 RibbonController
package com.tedu.sp06.consoller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import com.tedu.sp01.pojo.Item;
import com.tedu.sp01.pojo.Order;
import com.tedu.sp01.pojo.User;
import com.tedu.web.util.JsonResult;
@RestController
public class RibbonController {
@Autowired
private RestTemplate rt;
@GetMapping("/item-service/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId) {
// 向指定微服务地址发送 get 申请,并取得该服务的返回后果
//{1} 占位符,用 orderId 填充
return rt.getForObject("http://localhost:8001/{1}", JsonResult.class, orderId);
}
@PostMapping("/item-service/decreaseNumber")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {
// 发送 post 申请
return rt.postForObject("http://localhost:8001/decreaseNumber", items, JsonResult.class);
}
/
@GetMapping("/user-service/{userId}")
public JsonResult<User> getUser(@PathVariable Integer userId) {return rt.getForObject("http://localhost:8101/{1}", JsonResult.class, userId);
}
@GetMapping("/user-service/{userId}/score")
public JsonResult addScore(@PathVariable Integer userId, Integer score) {return rt.getForObject("http://localhost:8101/{1}/score?score={2}", JsonResult.class, userId, score);
}
/
@GetMapping("/order-service/{orderId}")
public JsonResult<Order> getOrder(@PathVariable String orderId) {return rt.getForObject("http://localhost:8201/{1}", JsonResult.class, orderId);
}
@GetMapping("/order-service")
public JsonResult addOrder() {return rt.getForObject("http://localhost:8201/", JsonResult.class);
}
}
2.4 启动服务, 并拜访测试
2.4.1 测试地址
http://eureka1:2001
http://localhost:3001/item-service/35
http://localhost:3001/user-service/7
http://localhost:3001/user-service/7/score?score=100
http://localhost:3001/order-service/123abc
http://localhost:3001/order-service/
3.ribbon 负载平衡引入
批改 sp06-ribbon 我的项目
1. 增加 ribbon 起步依赖(可选)
2.RestTemplate 设置 @LoadBanlance
3. 拜访门路批改为服务 id
3.1 增加 ribbon 起步依赖
eureka 依赖中曾经蕴含了 ribbon 依赖, 能够不增加.
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency>
3.2RestTemplate 增加 @LoadBalance 注解
@LoadBalance 负载平衡注解, 会对 RestTemplate 实例进行封装, 创立动静代理对象, 并切入 (AOP) 负载平衡代码, 把申请扩散散发到集群中的服务器中.
启动类批改
package com.tedu.sp06;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@EnableDiscoveryClient
@SpringBootApplication
public class Sp06RibbonApplication {
@LoadBalanced // 负载平衡注解
@Bean
public RestTemplate getRestTemplate() {return new RestTemplate();
}
public static void main(String[] args) {SpringApplication.run(Sp06RibbonApplication.class, args);
}
}
3.3 拜访门路设置为服务 id
package com.tedu.sp06.consoller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import com.tedu.sp01.pojo.Item;
import com.tedu.sp01.pojo.Order;
import com.tedu.sp01.pojo.User;
import com.tedu.web.util.JsonResult;
@RestController
public class RibbonController {
@Autowired
private RestTemplate rt;
@GetMapping("/item-service/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId) {
// 这里服务器门路用 service-id 代替,ribbon 会向服务的多台集群服务器散发申请
return rt.getForObject("http://item-service/{1}", JsonResult.class, orderId);
}
@PostMapping("/item-service/decreaseNumber")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {return rt.postForObject("http://item-service/decreaseNumber", items, JsonResult.class);
}
/
@GetMapping("/user-service/{userId}")
public JsonResult<User> getUser(@PathVariable Integer userId) {return rt.getForObject("http://user-service/{1}", JsonResult.class, userId);
}
@GetMapping("/user-service/{userId}/score")
public JsonResult addScore(@PathVariable Integer userId, Integer score) {return rt.getForObject("http://user-service/{1}/score?score={2}", JsonResult.class, userId, score);
}
/
@GetMapping("/order-service/{orderId}")
public JsonResult<Order> getOrder(@PathVariable String orderId) {return rt.getForObject("http://order-service/{1}", JsonResult.class, orderId);
}
@GetMapping("/order-service")
public JsonResult addOrder() {return rt.getForObject("http://order-service/", JsonResult.class);
}
}
3.4 拜访测试
http://localhost:3001/item-service/34
4.ribbon 重试引入
4.1 增加依赖 pom.xml 增加 spring-retry 依赖
<dependency>
<groupId>org.springframework.retry</groupId>
<artifactId>spring-retry</artifactId>
</dependency>
4.2application.yml 文件配置 ribbon 重试
spring:
application:
name: ribbon
server:
port: 3001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
ribbon:
MaxAutoRetriesNextServer: 2
MaxAutoRetries: 1
OkToRetryOnAllOperations: true
4.3 主启动类 ### 设置 RestTemplate 的申请工厂的超时属性
package com.tedu.sp06;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;
@EnableDiscoveryClient
@SpringBootApplication
public class Sp06RibbonApplication {
@LoadBalanced
@Bean
public RestTemplate getRestTemplate() {SimpleClientHttpRequestFactory f = new SimpleClientHttpRequestFactory();
f.setConnectTimeout(1000);
f.setReadTimeout(1000);
return new RestTemplate(f);
//RestTemplate 中默认的 Factory 实例中,两个超时属性默认是 -1,// 未启用超时,也不会触发重试
//return new RestTemplate();}
public static void main(String[] args) {SpringApplication.run(Sp06RibbonApplication.class, args);
}
}
4.4item-service 的 ItemController 增加提早代码,以便测试 ribbon 的重试机制
package com.tedu.sp02.item.controller;
import java.util.List;
import java.util.Random;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import com.tedu.sp01.pojo.Item;
import com.tedu.sp01.service.ItemService;
import com.tedu.web.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@RestController
public class ItemController {
@Autowired
private ItemService itemService;
@Value("${server.port}")
private int port;
@GetMapping("/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId) throws Exception {log.info("server.port="+port+", orderId="+orderId);
///-- 设置随机提早
long t = new Random().nextInt(5000);
if(Math.random()<0.6) {log.info("item-service-"+port+"- 暂停"+t);
Thread.sleep(t);
}
///~~
List<Item> items = itemService.getItems(orderId);
return JsonResult.ok(items).msg("port="+port);
}
@PostMapping("/decreaseNumber")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {itemService.decreaseNumbers(items);
return JsonResult.ok();}
}
拜访测试重启机制
http://localhost:3001/item-service/35
ribbon 的重试机制,在 feign 和 zuul 中进一步进行了封装,后续能够应用 feign 或 zuul 的重试机制
正文完