SpringCloud之Zuul高并发状况下接口限流(十二)

高并发下接口限流技术gauva(谷歌的框架) MySql最大链接数3000；

原理：框架每秒向桶里放100个令牌，接口请求来了先去拿令牌，拿到令牌后才能继续向后走，不然不容许向后执行；当接口请求太频繁的话就会拿不上令牌，此时就起到了限流的做用； 咱们在网关层作一个限流：

 1 /**
 2  * 订单限流  3  */
 4 @Component  5 public class OrderRateLimiterFilter extends ZuulFilter {  6 ​  7 ​  8     //每秒产生1000个令牌
 9     private static final RateLimiter RATE_LIMITER = RateLimiter.create(1000); 10 ​ 11  @Override 12     public String filterType() { 13         return PRE_TYPE; 14  } 15 ​ 16  @Override 17     public int filterOrder() { 18         return -4; 19  } 20 ​ 21 ​ 22 ​ 23  @Override 24     public boolean shouldFilter() { 25 ​ 26 ​ 27         RequestContext requestContext = RequestContext.getCurrentContext(); 28         HttpServletRequest request = requestContext.getRequest(); 29 ​ 30         //只对订单接口限流
31         if ("/apigateway/api/v1/order/save".equalsIgnoreCase(request.getRequestURI())){ 32             return true; 33  } 34 ​ 35         return false; 36  } 37 ​ 38  @Override 39     public Object run() throws ZuulException { 40         RequestContext requestContext = RequestContext.getCurrentContext(); 41         //RATE_LIMITER.tryAcquire()表示立马去拿令牌，只要拿不到就拦截；也能够设置一段时间内拿不到再拦截
42         if(!RATE_LIMITER.tryAcquire()){ 43             requestContext.setSendZuulResponse(false); 44  requestContext.setResponseStatusCode(HttpStatus.TOO_MANY_REQUESTS.value()); 45  } 46         return null; 47  } 48 ​ 49 ​ 50 ​ 51 } 52 ​