Spring Cloud Gateway中多规则限流（RequestRateLimiter覆盖问题）

场景

在SCG中配置多个RequestRateLimiter时，只能支持一个速率。

源码分析

跟踪源码发现下列两个关键类。

AbstractRateLimiter：初始化rarelimiter配置。

RequestRateLimiterGatewayFilterFactory：限流过滤器，包括定时刷新过滤器内容，和请求触发执行限流判断。

package org.springframework.cloud.gateway.filter.ratelimit;

...

public abstract class AbstractRateLimiter extends AbstractStatefulConfigurable
		implements RateLimiter, ApplicationListener {

	...
	@Override
	public void onApplicationEvent(FilterArgsEvent event) {
		Map args = event.getArgs();

		if (args.isEmpty() || !hasRelevantKey(args)) {
			return;
		}
        //获取路由id，包括默认的defaultFilters
		String routeId = event.getRouteId();
        //使用routeId+KeyResolver.hashcode作为配置id，防止重复
        routeId = routeId + event.getArgs().get("key-resolver").hashCode();
		C routeConfig = newConfig();
		if (this.configurationService != null) {
			this.configurationService.with(routeConfig)
					.name(this.configurationPropertyName).normalizedProperties(args)
					.bind();
		}
        //更新速率配置集合，routeId一致会覆盖
		getConfig().put(routeId, routeConfig);
	}

	...
}

 

package org.springframework.cloud.gateway.filter.factory;

...
/**
 * User Request Rate Limiter filter. See https://stripe.com/blog/rate-limiters and
 * https://gist.github.com/ptarjan/e38f45f2dfe601419ca3af937fff574d#file-1-check_request_rate_limiter-rb-L11-L34.
 */
@ConfigurationProperties("spring.cloud.gateway.filter.request-rate-limiter")
public class RequestRateLimiterGatewayFilterFactory extends
		AbstractGatewayFilterFactory {

	...

	@SuppressWarnings("unchecked")
	@Override
	public GatewayFilter apply(Config config) {
		KeyResolver resolver = getOrDefault(config.keyResolver, defaultKeyResolver);
		RateLimiter