js秒杀实现
秒杀系统核心实现思路
高并发秒杀系统的核心在于解决超卖问题和性能瓶颈,需结合前端优化、后端限流、缓存预热、异步处理等技术。
前端优化策略
静态资源CDN加速,减少主站请求压力 按钮倒计时与点击防抖,避免用户重复提交 独立秒杀页面域名,避免其他资源干扰
后端限流措施
Nginx层限流配置示例:
limit_req_zone $binary_remote_addr zone=seckill:10m rate=100r/s;
location /seckill {
limit_req zone=seckill burst=50 nodelay;
}
接口级令牌桶算法实现:
const RateLimiter = require('limiter').RateLimiter;
const limiter = new RateLimiter({tokensPerInterval: 100, interval: "second"});
async function checkRateLimit() {
const remaining = await limiter.removeTokens(1);
return remaining >= 0;
}
库存预热方案
Redis预减库存Lua脚本:

local stock = tonumber(redis.call('GET', KEYS[1]))
if stock <= 0 then return 0 end
redis.call('DECR', KEYS[1])
return 1
分段锁优化实现:
const segmentLock = new Map();
async function reduceStock(productId) {
const segment = productId % 16;
if(!segmentLock.has(segment)) {
segmentLock.set(segment, new Mutex());
}
const release = await segmentLock.get(segment).acquire();
try {
// 执行库存操作
} finally {
release();
}
}
异步订单处理
消息队列消费模式示例:
const amqp = require('amqplib');
async function processOrder() {
const conn = await amqp.connect('amqp://localhost');
const channel = await conn.createChannel();
await channel.assertQueue('order_queue');
channel.consume('order_queue', msg => {
// 处理订单逻辑
channel.ack(msg);
});
}
数据一致性保障
分布式事务解决方案:

const Saga = require('node-saga');
const saga = new Saga({
seckill: {
execute: async (payload) => {
// 扣减库存
},
compensate: async (payload) => {
// 恢复库存
}
},
createOrder: {
// 订单创建逻辑
}
});
压测与监控
Locust压测脚本示例:
from locust import HttpUser, task
class SeckillUser(HttpUser):
@task
def seckill(self):
self.client.post("/seckill", json={"productId": 1})
Prometheus监控指标配置:
const client = require('prom-client');
const gauge = new client.Gauge({
name: 'seckill_concurrent',
help: 'Current seckill requests'
});
function updateMetric() {
gauge.set(currentConcurrent);
}
容灾降级方案
Hystrix熔断配置:
const Hystrix = require('hystrixjs');
Hystrix.config.init({
"seckillCommand": {
"circuitBreakerErrorThresholdPercentage": 50,
"circuitBreakerSleepWindowInMilliseconds": 5000
}
});
系统需根据实际业务场景调整参数,建议采用灰度发布验证方案可靠性。监控指标应包含QPS、成功率、响应时间等核心维度,建立多级报警机制。






