5、Spring Cloud Ribbon
- 2020 年 12 月 8 日
- 筆記
- SpringCloud
1.Ribbon簡介
(1).Ribbon介紹
Spring Cloud Ribbon是基於Netflix Ribbon實現的一套客戶端負載均衡的工具。
Ribbon是Netflix發佈的開源項目,主要功能是提供客戶端的軟件負載均衡算法,將Netflix的中間層服務連接在一起。Ribbon客戶端組件提供一系列完善的配置項如連接超時,重試等。簡單的說,就是在配置文件中列出Load Balancer(簡稱LB)後面所有的機器,Ribbon會自動的幫助你基於某種規則(如簡單輪詢,隨機連接等)去連接這些機器。我們也很容易使用Ribbon實現自定義的負載均衡算法。
(2).Ribbon作用
Ribbon是基於Netflix Ribbon實現的一套客戶端負載均衡(LB)的工具。
LB(負載均衡):集中式LB和進程內LB。
集中式LB:即在服務的消費方和提供方之間使用獨立的LB設施(可以是硬件,如F5, 也可以是軟件,如nginx), 由該設施負責把訪問請求通過某種策略轉發至服務的提供方;
F5://baike.baidu.com/item/F5%E6%96%B9%E6%A1%88/1121377?fr=aladdin |
進程內LB:將LB邏輯集成到消費方,消費方從服務註冊中心獲知有哪些地址可用,然後自己再從這些地址中選擇出一個合適的服務器。
Ribbon就屬於進程內LB,它只是一個類庫,集成於消費方進程,消費方通過它來獲取到服務提供方的地址。
官方文檔:
//github.com/Netflix/ribbon/wiki
//github.com/Netflix/ribbon/wiki/Getting-Started
2.Ribbon配置
修改microservicecloud-consumer-dept-80工程
(1).修改pom.xml文件
修改部分:
<!– Ribbon相關 –> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-ribbon</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-config</artifactId> </dependency> </dependencies> |
完整部分:
<?xml version=”1.0″ encoding=”UTF-8″?> <project xmlns=”//maven.apache.org/POM/4.0.0″ xmlns:xsi=”//www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=”//maven.apache.org/POM/4.0.0 //maven.apache.org/xsd/maven-4.0.0.xsd”> <parent> <artifactId>microservicecloud</artifactId> <groupId>com.hosystem</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion>
<artifactId>microservicecloud-consumer-dept-80</artifactId> <!–<description>部門微服務消費者</description>–>
<dependencies> <dependency><!– 自己定義的api –> <!–注意:groupId我們需要由com.hosystem.springcloud 變成com.hosystem就不會出現‘Dependency ‘com.hosystem.springcloud:microservicecloud-api:1.0-SNAPSHOT’ not found’錯誤–> <groupId>com.hosystem</groupId> <artifactId>microservicecloud-api</artifactId> <version>${project.version}</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!– 修改後立即生效,熱部署 –> <dependency> <groupId>org.springframework</groupId> <artifactId>springloaded</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> </dependency>
<!– Ribbon相關 –> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-ribbon</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-config</artifactId> </dependency> </dependencies>
</project> |
(2).修改application.yml
追加eureka的服務註冊地址。
修改部分:
eureka: client: register-with-eureka: false service-url: defaultZone: //eureka7001.com:7001/eureka/,//eureka7002.com:7002/eureka/,//eureka7003.com:7003/eureka/ |
完整部分:
server: port: 80
eureka: client: register-with-eureka: false service-url: defaultZone: //eureka7001.com:7001/eureka/,//eureka7002.com:7002/eureka/,//eureka7003.com:7003/eureka/ |
(3).修改ConfigBean.java
對ConfigBean進行新註解@LoadBalanced,獲得Rest時加入Ribbon的配置;
package com.hosystem.springcloud.cfgbeans;
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 ConfigBean //boot —> spring applicationContext.xml === @Configuration配置 ConfigBean = applicationContext.xml { @Bean @LoadBalanced //Spring Cloud Ribbon是基於Netflix Ribbon實現的一套客戶端負載均衡的工具。 public RestTemplate getRestTemplate() { return new RestTemplate(); } }
//applicationContext.xml —> @Configuration public class ConfigBean {} //<bean id=UserService” class=”com.hosystem.tmall.UserServiceImple> |
(4).修改DeptConsumer80_App.java
主啟動類DeptConsumer80_App添加@EnableEurekaClient
package com.hosystem.springcloud;
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
@SpringBootApplication @EnableEurekaClient public class DeptConsumer80_App { public static void main(String[] args) { SpringApplication.run(DeptConsumer80_App.class, args); } } |
(5).修改DeptController_Consumer.java
修改DeptController_Consumer客戶端訪問類
package com.hosystem.springcloud.controller;
import com.hosystem.springcloud.entities.Dept; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate;
@RestController //注:這裡一定不能忘記註解@RestController 否則出現404; public class DeptController_Consumer {
/** * 使用restTemplate訪問restful接口非常的簡單; * (url, requestMap, ResponseBean.class)三個參數代表REST請求地址、請求參數、HTTP響應轉換被轉換成的對象類型 */ // private static final String REST_URL_PREFIX = “//localhost:8001”; //修改為微服務名 實現名字訪問微服務 private static final String REST_URL_PREFIX = “//MICROSERVICECLOUD-DEPT”;
@Autowired private RestTemplate restTemplate;
@RequestMapping(value=“/consumer/dept/add”) public boolean add(Dept dept) { return restTemplate.postForObject(REST_URL_PREFIX+“/dept/add”, dept, Boolean.class); }
@RequestMapping(value=“/consumer/dept/get/{id}”) public Dept get(@PathVariable(“id”) Long id) { return restTemplate.getForObject(REST_URL_PREFIX+“/dept/get/”+id, Dept.class); }
//@SuppressWarnings(“unchecked”):壓制警告,因為我們使用了過期的方法 @SuppressWarnings(“unchecked”) @RequestMapping(value=“/consumer/dept/list”) public List<Dept> list() { return restTemplate.getForObject(REST_URL_PREFIX+“/dept/list”, List.class); }
//測試@EnableDiscoveryClient,消費端可以調用服務發現 @RequestMapping(value=“/consumer/dept/discovery”) public Object discovery() { return restTemplate.getForObject(REST_URL_PREFIX+“/dept/discovery”, Object.class); } } /** * JDBC Spring JDBCTemplate * Spring RestTemplate */ |
(6).啟動eureka、provider、consumer
先啟動3個eureka7001、eureka7002、eureka7003集群後,再啟動microservicecloud-provider-dept-8001並註冊進eureka,最後啟動microservicecloud-consumer-dept-80。
(7).測試
//localhost/consumer/dept/get/1 //localhost/consumer/dept/list //localhost/consumer/dept/add?dname=大數據部 |
(8).總結
Ribbon和Eureka整合後Consumer可以直接調用服務而不用再關心地址和端口號
3.Ribbon負載均衡
(1).Ribbon架構介紹
Ribbon在工作時分成兩步:第一步先選擇 EurekaServer ,它優先選擇在同一個區域內負載較少的server.第二步再根據用戶指定的策略,在從server取到的服務註冊列表中選擇一個地址。其中Ribbon提供了多種策略:比如輪詢、隨機和根據響應時間加權。
(2).創建provider8002、provider8003
[1].創建工程provider8002
[2].創建工程provider8003
(3).配置pom文件
[1].配置provider8002 pom文件
<?xml version=”1.0″ encoding=”UTF-8″?> <project xmlns=”//maven.apache.org/POM/4.0.0″ xmlns:xsi=”//www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=”//maven.apache.org/POM/4.0.0 //maven.apache.org/xsd/maven-4.0.0.xsd”> <parent> <artifactId>microservicecloud</artifactId> <groupId>com.hosystem</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion>
<artifactId>microservicecloud-provider-dept-8002</artifactId>
<dependencies> <dependency><!– 引入自己定義的api通用包,可以使用Dept部門Entity –> <groupId>com.hosystem</groupId> <artifactId>microservicecloud-api</artifactId> <version>${project.version}</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-core</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jetty</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> </dependency> <!– 修改後立即生效,熱部署 –> <dependency> <groupId>org.springframework</groupId> <artifactId>springloaded</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> </dependency>
<!– 將微服務provider側註冊進eureka –> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-config</artifactId> </dependency>
<!– actuator監控信息完善 –> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> </dependencies> </project> |
[2].配置provider8003 pom文件
<?xml version=”1.0″ encoding=”UTF-8″?> <project xmlns=”//maven.apache.org/POM/4.0.0″ xmlns:xsi=”//www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=”//maven.apache.org/POM/4.0.0 //maven.apache.org/xsd/maven-4.0.0.xsd”> <parent> <artifactId>microservicecloud</artifactId> <groupId>com.hosystem</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion>
<artifactId>microservicecloud-provider-dept-8003</artifactId>
<dependencies> <dependency><!– 引入自己定義的api通用包,可以使用Dept部門Entity –> <groupId>com.hosystem</groupId> <artifactId>microservicecloud-api</artifactId> <version>${project.version}</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-core</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jetty</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> </dependency> <!– 修改後立即生效,熱部署 –> <dependency> <groupId>org.springframework</groupId> <artifactId>springloaded</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> </dependency>
<!– 將微服務provider側註冊進eureka –> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-config</artifactId> </dependency>
<!– actuator監控信息完善 –> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> </dependencies> </project> |
(4).配置yml文件
修改的地方有端口、數據庫鏈接、實例id(instance-id);對外暴露的統一服務實例名一定不能修改(name: microservicecloud-dept)
[1].配置provider8002 yml文件
server: port: 8002
mybatis: config-location: classpath:mybatis/mybatis.cfg.xml # mybatis配置文件所在路徑 type-aliases-package: com.hosytem.springcloud.entities # 所有Entity別名類所在包 mapper-locations: – classpath:mybatis/mapper/**/*.xml # mapper映射文件
#name spring.application.name=microservicecloud-dept 很重要很重要很重要 spring: application: name: microservicecloud-dept datasource: type: com.alibaba.druid.pool.DruidDataSource # 當前數據源操作類型 driver-class-name: org.gjt.mm.mysql.Driver # mysql驅動包 url: jdbc:mysql://192.168.188.188:3306/cloudDB02 # 數據庫名稱 username: root password: 123456 dbcp2: min-idle: 5 # 數據庫連接池的最小維持連接數 initial-size: 5 # 初始化連接數 max-total: 5 # 最大連接數 max-wait-millis: 200 # 等待連接獲取的最大超時時間
eureka: client: #客戶端註冊進eureka服務列表內 service-url: # defaultZone: //localhost:7001/eureka defaultZone: //eureka7001.com:7001/eureka/,//eureka7002.com:7002/eureka/,//eureka7003.com:7003/eureka/ instance: instance-id: microservicecloud-dept8002 prefer-ip-address: true #訪問路徑可以顯示IP地址 info: app.name: hosystem-microservicecloud company.name: www.hosystem.com build.artifactId: $project.artifactId$ build.version: $project.version$ |
[2].配置provider8003 yml文件
server: port: 8003
mybatis: config-location: classpath:mybatis/mybatis.cfg.xml # mybatis配置文件所在路徑 type-aliases-package: com.hosytem.springcloud.entities # 所有Entity別名類所在包 mapper-locations: – classpath:mybatis/mapper/**/*.xml # mapper映射文件
#name spring.application.name=microservicecloud-dept 很重要很重要很重要 spring: application: name: microservicecloud-dept datasource: type: com.alibaba.druid.pool.DruidDataSource # 當前數據源操作類型 driver-class-name: org.gjt.mm.mysql.Driver # mysql驅動包 url: jdbc:mysql://192.168.188.188:3306/cloudDB03 # 數據庫名稱 username: root password: 123456 dbcp2: min-idle: 5 # 數據庫連接池的最小維持連接數 initial-size: 5 # 初始化連接數 max-total: 5 # 最大連接數 max-wait-millis: 200 # 等待連接獲取的最大超時時間
eureka: client: #客戶端註冊進eureka服務列表內 service-url: # defaultZone: //localhost:7001/eureka defaultZone: //eureka7001.com:7001/eureka/,//eureka7002.com:7002/eureka/,//eureka7003.com:7003/eureka/ instance: instance-id: microservicecloud-dept8003 prefer-ip-address: true #訪問路徑可以顯示IP地址 info: app.name: hosystem-microservicecloud company.name: www.hosystem.com build.artifactId: $project.artifactId$ build.version: $project.version$ |
(5).配置主啟動類
[1].DeptProvider8002_App
|
[2].DeptProvider8002_App
|
(6).創建數據庫database8002、database8003
新建8002/8003數據庫,各自微服務分別連各自的數據庫。
[1].創建database8002
DROP DATABASE IF EXISTS cloudDB02;
CREATE DATABASE cloudDB02 CHARACTER SET UTF8;
USE cloudDB02;
CREATE TABLE dept ( deptno BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT, dname VARCHAR(60), db_source VARCHAR(60) );
INSERT INTO dept(dname,db_source) VALUES(‘開發部’,DATABASE()); INSERT INTO dept(dname,db_source) VALUES(‘人事部’,DATABASE()); INSERT INTO dept(dname,db_source) VALUES(‘財務部’,DATABASE()); INSERT INTO dept(dname,db_source) VALUES(‘市場部’,DATABASE()); INSERT INTO dept(dname,db_source) VALUES(‘運維部’,DATABASE());
SELECT * FROM dept; |
[2].創建database8003
DROP DATABASE IF EXISTS cloudDB03;
CREATE DATABASE cloudDB03 CHARACTER SET UTF8;
USE cloudDB03;
CREATE TABLE dept ( deptno BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT, dname VARCHAR(60), db_source VARCHAR(60) );
INSERT INTO dept(dname,db_source) VALUES(‘開發部’,DATABASE()); INSERT INTO dept(dname,db_source) VALUES(‘人事部’,DATABASE()); INSERT INTO dept(dname,db_source) VALUES(‘財務部’,DATABASE()); INSERT INTO dept(dname,db_source) VALUES(‘市場部’,DATABASE()); INSERT INTO dept(dname,db_source) VALUES(‘運維部’,DATABASE());
SELECT * FROM dept; |
(7).啟動eureka、provider、consumer
啟動3個eureka集群配置區,在啟動provider後,我們需要隨便打開一個eureka看provider是否都註冊上了。
啟動3個provider微服務並各自測試通過
//localhost:8001/dept/list //localhost:8002/dept/list //localhost:8003/dept/list |
啟動microservicecloud-consumer-dept-80
(8).訪問Dept微服務
客戶端通過Ribbo完成負載均衡並訪問上一步的Dept微服務
注意觀察看到返回的數據庫名字,各不相同,負載均衡實現
(9).總結
Ribbon其實就是一個軟負載均衡的客戶端組件,他可以和其他所需請求的客戶端結合使用,和eureka結合只是其中的一個實例。
4.Ribbon核心組件
(1).查看IRle接口
(2).查看IRleILoadBalancer接口
(3).查看AbstractLoadBalancer接口
(4).使用RandomRule算法
修改consumer-dept-80的ConfigBean.java.
package com.hosystem.springcloud.cfgbeans;
import com.netflix.loadbalancer.IRule; import com.netflix.loadbalancer.RandomRule; import com.netflix.loadbalancer.RetryRule; import com.netflix.loadbalancer.RoundRobinRule; 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 ConfigBean //boot —> spring applicationContext.xml === @Configuration配置 ConfigBean = applicationContext.xml { @Bean @LoadBalanced //Spring Cloud Ribbon是基於Netflix Ribbon實現的一套客戶端負載均衡的工具。 public RestTemplate getRestTemplate() { return new RestTemplate(); }
//選擇我們使用的算法 // RoundRobinRule:輪詢 // RandomRule:隨機 // AvailabilityFilteringRule:先過濾多次訪問故障處於斷路器跳閘狀態的服務,還有並發的連接數量超過閾值的服務,然後對剩餘的服務列表按照輪詢策略進行訪問 // WeightedResponseTimeRule:根據平均響應時間計算所有服務的權重,響應時間越快服務權重越大被選中的概率越高。剛啟動時如果統計信息不足,則使用RoundRobinRule策略,等統計信息足夠,會切換到WeightedResponseTimeRule // RetryRule:先按照RoundRobinRule的策略獲取服務,如果獲取服務失敗則在指定時間內會進行重試,獲取可用的服務 // BestAvailableRule:會先過濾掉由於多次訪問故障而處於斷路器跳閘狀態的服務,然後選擇一個並發量最小的服務 // ZoneAvoidanceRule:默認規則,複合判斷server所在區域的性能和server的可用性選擇服務器 @Bean public IRule myRule(){
// return new RoundRobinRule(); //輪詢算法 // return new RandomRule(); //隨機算法 return new RetryRule(); //先按照RoundRobinRule的策略獲取服務,如果獲取服務失敗則在指定時間內會進行重試,獲取可用的服務 } }
//applicationContext.xml —> @Configuration public class ConfigBean {} //<bean id=UserService” class=”com.hosystem.tmall.UserServiceImple> |
5.Ribbon自定義
修改microservicecloud-consumer-dept-80
(1).修改主啟動類
修改consumer-dept-80的主啟動類
package com.hosystem.springcloud;
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.netflix.eureka.EnableEurekaClient; import org.springframework.cloud.netflix.ribbon.RibbonClient;
@SpringBootApplication @EnableEurekaClient @RibbonClient(name=“MICROSERVICECLOUD-DEPT”,configuration=MySelfRule.class) //在啟動該微服務的時候就能去加載我們的自定義Ribbon配置類,從而使配置生效 public class DeptConsumer80_App { public static void main(String[] args) { SpringApplication.run(DeptConsumer80_App.class, args); } } |
(2).配置事項
官方文檔明確給出了警告:這個自定義配置類不能放在@ComponentScan所掃描的當前包下以及子包下,否則我們自定義的這個配置類就會被所有的Ribbon客戶端所共享,也就是說我們達不到特殊化定製的目的了。
簡單說,就是我們不能夠在主啟動類(DeptConsumer80_App)所在的包及其子包下創建我們自定義規則類。
如,我們新創建了myrule包,不能夠創建在springcloud包下,因為主啟動類在springcloud包下了。
(3).自定義步驟
[1].新建package
根據配置事項,我們得知需要重新創建一個包不能和主啟動類在一個包下。我們創建com.hosystem.myrule包。
[2].自定義Robbin規則類
package com.hosystem.myrule;
import com.netflix.loadbalancer.IRule; import com.netflix.loadbalancer.RandomRule; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;
@Configuration public class MySelfRule { @Bean public IRule myRule() { return new RandomRule();//Ribbon默認是輪詢,我自定義為隨機 } } |
[3].修改主啟動類
package com.hosystem.springcloud;
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.netflix.eureka.EnableEurekaClient; import org.springframework.cloud.netflix.ribbon.RibbonClient;
@SpringBootApplication @EnableEurekaClient @RibbonClient(name=“MICROSERVICECLOUD-DEPT”,configuration=MySelfRule.class) //在啟動該微服務的時候就能去加載我們的自定義Ribbon配置類,從而使配置生效 public class DeptConsumer80_App { public static void main(String[] args) { SpringApplication.run(DeptConsumer80_App.class, args); } } |
[4].測試
(4).自定義規則深度解析
依舊輪詢策略,但是加上新需求,每個服務器要求被調用5次。也即以前是每台機器一次,現在是每台機器5次。
[1].源碼解析
//github.com/Netflix/ribbon/blob/master/ribbon-loadbalancer/src/main/java/com/netflix/loadbalancer/RandomRule.java |
[2].RandomRule_Hosystem.java
參考源碼修改為我們需求要求的RandomRule_Hosystem.java
package com.hosystem.myrule;
import com.netflix.client.config.IClientConfig; import com.netflix.loadbalancer.AbstractLoadBalancerRule; import com.netflix.loadbalancer.ILoadBalancer; import com.netflix.loadbalancer.Server;
import java.util.List; import java.util.concurrent.ThreadLocalRandom;
public class RandomRule_Hosystem extends AbstractLoadBalancerRule{
//total = 0 當total==5時 指向才能往下走 //index = 0 當前對外提供的服務器地址 //當total從5置為0時 我們index=1 private int total = 0; //總共被調用的次數,目前要求每台被調用5次 private int currentIndex = 0;//當前提供服務的機器號
/** * Randomly choose from all living servers */ // @edu.umd.cs.findbugs.annotations.SuppressWarnings(value = “RCN_REDUNDANT_NULLCHECK_OF_NULL_VALUE”) public Server choose(ILoadBalancer lb, Object key) { if (lb == null) { return null; } Server server = null;
while (server == null) { if (Thread.interrupted()) { return null; } List<Server> upList = lb.getReachableServers(); List<Server> allList = lb.getAllServers();
int serverCount = allList.size(); if (serverCount == 0) { /* * No servers. End regardless of pass, because subsequent passes * only get more restrictive. */ return null; }
// int index = chooseRandomInt(serverCount); // server = upList.get(index); // private int total = 0; //總共被調用的次數,目前要求每台被調用5次 // private int currentIndex = 0;//當前提供服務的機器號 //分析,因為我們需要訪問5次 但是微服務只有8001 8002 8003三台 所以我們需要設定currentIndex>=upList.size()時重新從8001開始 if(total < 5) { server = upList.get(currentIndex); total++; }else { total = 0; currentIndex++; if(currentIndex >= upList.size()) { currentIndex = 0; }
}
if (server == null) { /* * The only time this should happen is if the server list were * somehow trimmed. This is a transient condition. Retry after * yielding. */ Thread.yield(); continue; }
if (server.isAlive()) { return (server); }
// Shouldn’t actually happen.. but must be transient or a bug. server = null; Thread.yield(); }
return server;
}
protected int chooseRandomInt(int serverCount) { return ThreadLocalRandom.current().nextInt(serverCount); }
@Override public Server choose(Object key) { return choose(getLoadBalancer(), key); }
@Override public void initWithNiwsConfig(IClientConfig iClientConfig) {
} } |
[3].MySelfRule.java
package com.hosystem.myrule;
import com.netflix.loadbalancer.IRule; import com.netflix.loadbalancer.RandomRule; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;
@Configuration public class MySelfRule { @Bean public IRule myRule() { // return new RandomRule();//Ribbon默認是輪詢,我自定義為隨機
return new RandomRule_Hosystem(); //自定義每台機器訪問5次 } } |
[4].測試
參考文檔:
//baike.baidu.com/item/F5%E6%96%B9%E6%A1%88/1121377?fr=aladdin
//github.com/Netflix/ribbon/wiki
//github.com/Netflix/ribbon/wiki/Getting-Started