SpingCloud(H版&alibaba)框架开发教程-23 Ribbion负载轮询算法原理及手写轮询算法
负载均衡算法原理:rest接口第几次请求数
%服务器集群总数量
=实际调用服务器位置下标
,每次服务重启后rest接口计数从1开始
手写轮询算法:
cloud-consumer-order80模块
注释掉com.antherd.springcloud.config.ApplicationContextConfig中代码
// @LoadBalanced // 使RestTemplate具有负载均衡能力
注释掉com.antherd.springcloud.OrderMain80中注释
// @RibbonClient(name = "CLOUD-PAYMENT-SERVICE", configuration = MyRule.class)
新建类:com.antherd.springcloud.lb.LoadBalancer
package com.antherd.springcloud.lb;
import java.util.List;
import org.springframework.cloud.client.ServiceInstance;
public interface LoadBalancer {
ServiceInstance instances(List<ServiceInstance> serviceInstances);
}
新建类:com.antherd.springcloud.lb.LoadBalancer.MyLB
package com.antherd.springcloud.lb;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;
@Component
public class MyLB implements LoadBalancer {
private AtomicInteger atomicInteger = new AtomicInteger(0);
public final int getAndIncrement() {
int current;
int next;
do {
current = this.atomicInteger.get();
next = current >= 2147483647 ? 0 : current + 1;
} while (!this.atomicInteger.compareAndSet(current, next));
System.out.println("*****第几次访问, 次数next*****: " + next);
return next;
}
@Override
public ServiceInstance instances(List<ServiceInstance> serviceInstances) {
int index = getAndIncrement() % serviceInstances.size();
return serviceInstances.get(index);
}
}
修改com.antherd.springcloud.contorller.OrderController
package com.antherd.springcloud.contorller;
import com.antherd.springcloud.entities.CommonResult;
import com.antherd.springcloud.entities.Payment;
import com.antherd.springcloud.lb.MyLB;
import java.net.URI;
import java.util.List;
import javax.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.http.ResponseEntity;
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.RestController;
import org.springframework.web.client.RestTemplate;
@RestController
@Slf4j
public class OrderController {
//private static final String PAYMENT_URL = "http://localhost:8001";
private static final String PAYMENT_URL = "http://CLOUD-PAYMENT-SERVICE";
@Resource
private RestTemplate restTemplate;
@Resource
private MyLB loadBalancer;
@Resource
private DiscoveryClient discoveryClient;
@PostMapping("/consumer/payment")
public CommonResult<Payment> create(Payment payment) {
return restTemplate.postForObject(PAYMENT_URL + "/payment", payment, CommonResult.class);
}
@GetMapping("/consumer/payment/{id}")
public CommonResult<Payment> getPayment(@PathVariable Long id) {
return restTemplate.getForObject(PAYMENT_URL + "/payment/" + id, CommonResult.class);
}
@GetMapping("/consumer/payment2/{id}")
public CommonResult<Payment> getPayment2(@PathVariable Long id) {
ResponseEntity<CommonResult> entity = restTemplate.getForEntity(PAYMENT_URL + "/payment/" + id, CommonResult.class);
if (entity.getStatusCode().is2xxSuccessful()) {
return entity.getBody();
} else {
return new CommonResult<>(444, "操作失败");
}
}
@GetMapping(value = "/consumer/payment/lb")
public String getPaymentLB() {
List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-PAYMENT-SERVICE");
if (instances == null || instances.size() == 0) {
return null;
}
ServiceInstance serviceInstance = loadBalancer.instances(instances);
URI uri = serviceInstance.getUri();
return restTemplate.getForObject(uri + "/payment/lb", String.class);
}
}
新建接口:com.antherd.springcloud.lb.LoadBalancer
cloud-provider-payment8001、cloud-provider-payment8002模块
在com.antherd.springcloud.controller.PaymentController中添加新接口:
@GetMapping(value = "/payment/lb")
public String getPaymentLB() {
return serverPort;
}
测试
启动:cloud-eureka-server7001,cloud-eureka-server7002,cloud-provider-payment8001,cloud-provider-payment8002,cloud-consumer-order80五个模块
访问:http://localhost/consumer/payment/lb
本文地址:https://blog.csdn.net/REX1129/article/details/111932921
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