简单负载均衡工具类

悠悠 2023-02-16 00:44 1阅读 0赞

看到一个哥们写的一个简单的工具类感觉挺好玩的:  
负载均衡有很多种方法,权重呀,随机,轮询等等;  
实现一个最简单的,那就是随机和轮询,轮询有个注意的就是,在多线程情况下也是ok的:

import java.util.Random;
    import java.util.concurrent.CompletableFuture;
    import java.util.concurrent.TimeUnit;
    import java.util.concurrent.atomic.AtomicInteger;
    
    /** * 负载均衡工具类 */
    public class LoadBalancerUtil { 
    
      private static final Random rand = new Random();
      private static final AtomicInteger nextCyclicCounter = new AtomicInteger(0);
    
      /** * 随机算法 * * @param number 随机数的上线 * @return 返回 0 ~ (number-1) 的随机数 */
      public static int randomRule(int number) { 
        return rand.nextInt(number);
      }
    
      /** * 轮巡算法 * * @param modulo 取余的阔值 * @return 当前轮巡的数值 0 ~ (number-1) */
      public static int roundRule(int modulo) { 
        int current;
        int next;
        do { 
          current = nextCyclicCounter.get();
          next = (current + 1) % modulo;
        } while (!nextCyclicCounter.compareAndSet(current, next));
        return next;
      }
    
    
      public static void main(String[] args) { 
    // for (int i = 0; i < 1000; i++) { 
    // System.out.println(randomRule(3));
    // }
    // System.out.println("===============================");
    // for (int i = 0; i < 1000; i++) { 
    // System.out.println(roundRule(3));
    // }
    
        for (int i = 0; i < 10; i++) { 
          CompletableFuture.runAsync(() -> { 
            while (true) { 
              System.out.println(roundRule(50));
            }
          });
        }
        try { 
          TimeUnit.SECONDS.sleep(30);
        } catch (InterruptedException e) { 
          e.printStackTrace();
        }
    
      }
    }