ribbon  客户端负载均衡

Feign  轻量级 RESTful 客户端
Feign makes writing java http clients easier
内置Ribbon 实现 客户端负载均衡
使用Feign的注解定义接口

OpenFeign 在Feign的基础上支持SpringMVC注解，如@RequesMapping等

@FeignClient可以解析SpringMVC的@RequestMapping 等注解
通过动态代理的方式产生实现类

feign ribbon  可以脱离 spring 独立使用




客户端负载均衡

ILoadBalancer balancer = new BaseLoadBalancer();
List servers = new ArrayList();
servers.add(new Server("localhost", 8080));
servers.add(new Server("localhost", 8081));
balancer.addServers(servers);
        
for(int i=0;i<10;i++){
    Server choosedServer = balancer.chooseServer(null);
    System.out.println(choosedServer);
}


服务列表可以在 注册中心 动态维护
        


private static interface InfoService{
    @RequestLine("GET /info")
    String info();
}

        
Properties properties = new Properties();
        
properties.put("demo.ribbon.MaxAutoRetries","1");
properties.put("demo.ribbon.OkToRetryOnAllOperations","true");
properties.put("demo.ribbon.ServerListRefreshInterval","2000");
properties.put("demo.ribbon.ConnectTimeout","2000");
properties.put("demo.ribbon.ReadTimeout","3000");
properties.put("demo.ribbon.listOfServers","localhost:8080,localhost:8090");
properties.put("demo.ribbon.EnablePrimeConnections","true");

// prefix demo ==> appName
// http://demo
        
ConfigurationManager.loadProperties(properties);
        
        
InfoService infoService = Feign.builder().client(RibbonClient.create())
//.encoder(new JacksonEncoder())
//.decoder(new JacksonDecoder())
.target(InfoService.class,"http://demo");
        
for(int i=0;i<10;i++) {
    System.out.println(infoService.info());
}
        


服务端
https://gitee.com/dyyx/springboothello

mvn spring-boot:run -Dstart-class=demo.DemoApp -Dspring-boot.run.arguments=--server.port=8080
mvn spring-boot:run -Dstart-class=demo.DemoApp -Dspring-boot.run.arguments=--server.port=8090


pom依赖
com.netflix.ribbon:ribbon-loadbalancer:2.2.5
com.netflix.ribbon:ribbon-httpclient:2.2.5

com.netflix.archaius:archaius-core:0.7.6

io.github.openfeign:feign-core:9.5.1
io.github.openfeign:feign-ribbon:9.5.1
io.github.openfeign:feign-jackson:9.5.1

io.github.openfeign:feign-jackson:9.5.1


完整代码
https://gitee.com/dyyx/demos/tree/master/feign-riboon-demo