关于java:SpringCloud梳理ribbon

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@SpringBootApplicationpublic 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;@RestControllerpublic 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@SpringBootApplicationpublic 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;@RestControllerpublic 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@SpringBootApplicationpublic 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@RestControllerpublic 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