Ribbon负载均衡的简单使用

1.pom文件引用依赖

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2.在获取RestTemplate方法中添加Ribbon的@LoadBalanced注解

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3.仿造RandomRule自定义一个负载均衡的类

public class RandomRule extends AbstractLoadBalancerRule {

    /**
     * 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);

            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 clientConfig) {
		// TODO Auto-generated method stub
		
	}
}

4.在Springboot不能扫到的包自定义一个路由配置类，并把自定义的负载均衡算法类交给spring管理

@Configuration
public class RuleConfiguration {

    @Bean
    public IRule iRule(){
        return new PanRandomRule();
    }
}

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5.在Springboot启动类中添加@RibbonClient注解

@SpringBootApplication
@EnableEurekaClient
@RibbonClient(name = "springcloud.provider-dept",configuration = RuleConfiguration.class)
public class DeptConsumer_80 {

    public static void main(String[] args) {
        SpringApplication.run(DeptConsumer_80.class,args);
    }
}