官方文檔

https://github.com/alibaba/Sentinel/wiki/%E4%BB%8B%E7%BB%8D

Feign 中 使用 Sentinel 斷路器

http://www.reibang.com/p/8e769e365f88

在 SpringClouldGateway 的過(guò)濾器中進(jìn)行QPS限流

引入依賴(lài)

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>

添加限流的過(guò)濾器

LimitFilter

import com.alibaba.csp.sentinel.Entry;
import com.alibaba.csp.sentinel.SphU;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.RuleConstant;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
import com.gnl.commonlib.error.SystemError;
import com.gnl.gateway.util.HttpDataExtractor;
import lombok.extern.log4j.Log4j2;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.ArrayList;
import java.util.List;


@Log4j2
@Component
public class LimitFilter implements GlobalFilter, Ordered {

    @Override
    public int getOrder() {
        // 返回值用來(lái)指定執(zhí)行的順序葬项，數(shù)字越小，優(yōu)先級(jí)越高
        return 1;
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        String method = HttpDataExtractor.getMethod(exchange);
        String path = HttpDataExtractor.getPath(exchange);
        String userId = HttpDataExtractor.getHeader(exchange, "userId");

        // 被限流的資源名稱(chēng)（例如：GET /auth-service/auth/userInfo 123456）
        String resourceName = method + " " + path + " " + userId;

        // 不需要登錄的接口，直接放行
        if (userId == null) {
            log.info(resourceName + " pass");
            return chain.filter(exchange);
        }

        // 初始化限流規(guī)則
        initFlowRules(resourceName);
        Entry entry = null;
        try {
            // 設(shè)置被限流的資源名稱(chēng)
            entry = SphU.entry(resourceName);
        } catch (BlockException e) {
            // 被限流時(shí)捕獲BlockException,直接返回系統(tǒng)繁忙
            log.info(resourceName + " block");
            return HttpDataExtractor.returnData(SystemError.SYSTEM_IS_BUSY, exchange);
        } finally {
            if (entry != null) {
                entry.exit();
            }
        }

        // 未被限流，直接訪(fǎng)問(wèn)資源
        log.info(resourceName + " pass");
        return chain.filter(exchange);
    }

    private static void initFlowRules(String resourceName) {
        List<FlowRule> rules = new ArrayList<>();
        FlowRule rule = new FlowRule();
        rule.setResource(resourceName);
        rule.setGrade(RuleConstant.FLOW_GRADE_QPS);
        // 設(shè)置限流的 QPS 為 3，結(jié)合resourceName（GET /auth-service/auth/userInfo 666666）锅移，表示為用戶(hù)（666666）訪(fǎng)問(wèn)接口GET /auth-service/auth/userInfo的QPS大于3時(shí)嘶是，就會(huì)被限流
        rule.setCount(3);
        rules.add(rule);
        FlowRuleManager.loadRules(rules);
    }

}

HttpDataExtractor

import com.alibaba.fastjson.JSON;
import com.gnl.commonlib.base.BaseError;
import com.gnl.commonlib.base.BaseResponse;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.function.Consumer;

public class HttpDataExtractor {

    /**
     * 獲取請(qǐng)求頭
     */
    public static String getHeader(ServerWebExchange exchange, String key) {
        ServerHttpRequest request = exchange.getRequest();
        List<String> list = request.getHeaders().get(key);
        if (list == null || list.size() == 0) {
            return null;
        }
        return list.get(0);
    }

    /**
     * 獲得訪(fǎng)問(wèn)路徑
     */
    public static String getPath(ServerWebExchange exchange) {
        ServerHttpRequest request = exchange.getRequest();
        return request.getURI().getPath();
    }

    /**
     * 獲取請(qǐng)求方法
     */
    public static String getMethod(ServerWebExchange exchange) {
        ServerHttpRequest request = exchange.getRequest();
        return request.getMethod().toString();
    }

    /**
     * 添加請(qǐng)求頭
     */
    public static void addHeader(ServerWebExchange exchange, Consumer<HttpHeaders> httpHeaders) {
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpRequest serverHttpRequest = request.mutate().headers(httpHeaders).build();
        exchange.mutate().request(serverHttpRequest).build();
    }

    /**
     * 返回值的封裝
     */
    public static Mono<Void> returnData(BaseError baseError, ServerWebExchange exchange) {
        ServerHttpResponse response = exchange.getResponse();
        BaseResponse data = BaseResponse.error(baseError);
        byte[] datas = JSON.toJSONString(data).getBytes(StandardCharsets.UTF_8);
        DataBuffer buffer = response.bufferFactory().wrap(datas);

        response.setStatusCode(HttpStatus.OK);
        response.getHeaders().add("Content-Type", "application/json;charset=UTF-8");

        return response.writeWith(Mono.just(buffer));
    }
}

效果

使用jMeter進(jìn)行壓測(cè)行拢，0秒發(fā)送10個(gè)請(qǐng)求梨州，只有三個(gè)成功訪(fǎng)問(wèn)了資源痕囱，后面七個(gè)直接返回了系統(tǒng)繁忙

image

成功返回的信息

image

image