spring cloud gateway默认基于redis令牌桶算法进行微服务的限流保护，采用RateLimter限流算法来实现。
1.引入依赖包
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-circuitbreaker-resilience4j</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-circuitbreaker-reactor-resilience4j</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis-reactive</artifactId>
</dependency>
2、yml中配置redis
spring:
application:
name: mima-cloud-gateway
redis:
database: 1
host: localhost
port: 6379
password:
3、配置KeyResolver——RateLimiteConfig.java(接口限流/ip限流/用户限流)
package com.mkevin.gateway.config; import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Primary; import reactor.core.publisher.Mono; /** * 限流配置KeyResolver——有三种写法(接口限流/ip限流/用户限流) */ @Configuration public class RateLimiteConfig { /** * 接口限流：根据请求路径限流 * @return
*/
/* 如果不使用@Primary注解，会报如下错误，需要注意 Description: Parameter 1 of method requestRateLimiterGatewayFilterFactory in org.springframework.cloud.gateway.config.GatewayAutoConfiguration required a single bean, but 3 were found: - pathKeyResolver: defined by method 'pathKeyResolver' in class path resource [com/mkevin/gateway/config/RateLimiteConfig.class] - ipKeyResolver: defined by method 'ipKeyResolver' in class path resource [com/mkevin/gateway/config/RateLimiteConfig.class] - userKeyResolver: defined by method 'userKeyResolver' in class path resource [com/mkevin/gateway/config/RateLimiteConfig.class] Action: Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed */ @Bean @Primary public KeyResolver pathKeyResolver() { //写法1
return exchange -> Mono.just( exchange.getRequest() .getPath() .toString() ); /* //写法2 return new KeyResolver() { @Override public Mono<String> resolve(ServerWebExchange exchange) { return Mono.just(exchange.getRequest() .getPath() .toString()); } }; */ } /** * 根据请求IP限流 * @return
*/ @Bean public KeyResolver ipKeyResolver() { return exchange -> Mono.just( exchange.getRequest() .getRemoteAddress() .getHostName() ); } /** * 根据请求参数中的userId进行限流 * * 请求地址写法：http://localhost:8801/rate/123?userId=lisi * * @return
*/ @Bean public KeyResolver userKeyResolver() { return exchange -> Mono.just( exchange.getRequest() .getQueryParams() .getFirst("userId") ); } }
4、yml中配置spring.cloud.gateway.routes.filters
spring: cloud: gateway: routes: - id: rate-limit-demo uri: lb://mima-cloud-producer
predicates: #访问路径：http://localhost:8801/rate/123
- Path=/rate/** filters: - name: RequestRateLimiter args: # 令牌桶每秒填充平均速率, 允许用户每秒处理多少个请求。 redis-rate-limiter.replenishRate: 1 # 令牌桶的容量，允许在1s内完成的最大请求数。 redis-rate-limiter.burstCapacity: 2 # 使用SpEL表达式从Spring容器中获取Bean对象, 查看RateLimiteConfig实现类中的方法名 key-resolver: "#{@pathKeyResolver}" #key-resolver: "#{@ipKeyResolver}" #key-resolver: "#{@userKeyResolver}"
5、访问地址测试
http://localhost:8801/rate/123
当F5频繁刷新请求接口时，控制台会报429错误状态码，提示我们请求过多，如下：
[开始]请求路径:/rate/123 [应答]请求路径:/rate/123耗时:2ms 2020-09-08 16:23:27.253 DEBUG 18512 --- [ioEventLoop-4-1] o.s.w.s.adapter.HttpWebHandlerAdapter : [62eb90e0] Completed 429 TOO_MANY_REQUESTS 2020-09-08 16:23:27.394 DEBUG 18512 --- [ctor-http-nio-2] o.s.w.s.adapter.HttpWebHandlerAdapter : [62eb90e0] HTTP GET "/rate/123" corsFilter... run [开始]请求路径:/rate/123 [应答]请求路径:/rate/123耗时:2ms 2020-09-08 16:23:27.397 DEBUG 18512 --- [ioEventLoop-4-1] o.s.w.s.adapter.HttpWebHandlerAdapter : [62eb90e0] Completed 429 TOO_MANY_REQUESTS 2020-09-08 16:23:27.536 DEBUG 18512 --- [ctor-http-nio-2] o.s.w.s.adapter.HttpWebHandlerAdapter : [62eb90e0] HTTP GET "/rate/123" corsFilter... run
6、当发生限流时，会向redis中存储两个数据
127.0.0.1:1>keys *
1) "request_rate_limiter.{/rate/123}.timestamp"
2) "request_rate_limiter.{/rate/123}.tokens"
127.0.0.1:1>keys *
1) "request_rate_limiter.{0:0:0:0:0:0:0:1}.timestamp"
2) "request_rate_limiter.{0:0:0:0:0:0:0:1}.tokens"
127.0.0.1:1>keys *
1) "request_rate_limiter.{lisi}.timestamp"
2) "request_rate_limiter.{lisi}.tokens"
参数说明：
request_rate_limiter.{key}.timestamp：
存储的是当前时间的秒数，也就是System.currentTimeMillis()/1000或者Instant.now().getEpochSecond()。
request_rate_limiter.{key}.tokens：
存储的是当前这秒钟对应的可用令牌数量
7、完整yml配置文件
# 开启resilience4j断路器 # spring.cloud.circuitbreaker.resilience4j.enabled: true # 设置hystrix断路器超时时间 # hystrix.command.fallbackcmd.execution.isolation.thread.timeoutInMilliseconds: 2000 spring: application: name: mima-cloud-gateway redis: database: 1 host: localhost port: 6379 password: cloud: gateway: routes: - id: rate-limit-demo uri: lb://mima-cloud-producer
predicates: #访问路径：http://localhost:8801/rate/123
- Path=/rate/** filters: - name: RequestRateLimiter args: # 令牌桶每秒填充平均速率, 允许用户每秒处理多少个请求。 redis-rate-limiter.replenishRate: 1 # 令牌桶的容量，允许在1s内完成的最大请求数。 redis-rate-limiter.burstCapacity: 2 # 使用SpEL表达式从Spring容器中获取Bean对象, 查看RateLimiteConfig实现类中的同名方法 #key-resolver: "#{@pathKeyResolver}" #key-resolver: "#{@ipKeyResolver}" #请求地址写法：http://localhost:8801/rate/123?userId=lisi key-resolver: "#{@userKeyResolver}" # The RequestRateLimiter GatewayFilter Factory # The Redis RateLimiter # Modify a Request Body GatewayFilter Factory 测试版本，未来可能改动 # Modify a Response Body GatewayFilter Factory 测试版本，未来可能改动 server: port: 8801 eureka: client: serviceUrl: #defaultZone: http://kevin:123456@localhost:8761/eureka/ defaultZone: http://localhost:8761/eureka/ instance: prefer-ip-address: true #instance-id: ${spring.application.name}:${spring.cloud.client.ip-address:}:${server.port} instance-id: ${spring.application.name}:${server.port} debug: true management: endpoints: web: exposure: include: '*' endpoint: health: show-details: always shutdown: true