Redis

RateLimiterRedis

Redis >=2.6.12

Usage

It supports both redis and ioredis clients.

Redis client must be created with offline queue switched off.

See all options here

const redis = require('redis');
const redisClient = redis.createClient({ enable_offline_queue: false });

const Redis = require('ioredis');
const redisClient = new Redis({ enableOfflineQueue: false });

const { RateLimiterRedis } = require('rate-limiter-flexible');

// It is recommended to process Redis errors and setup some reconnection strategy
redisClient.on('error', (err) => {
  
});

const opts = {
  // Basic options
  storeClient: redisClient,
  points: 5, // Number of points
  duration: 5, // Per second(s)
  
  // Custom
  execEvenly: false, // Do not delay actions evenly
  blockDuration: 0, // Do not block if consumed more than points
  keyPrefix: 'rlflx', // must be unique for limiters with different purpose
};

const rateLimiterRedis = new RateLimiterRedis(opts);

rateLimiterRedis.consume(remoteAddress)
    .then((rateLimiterRes) => {
      // ... Some app logic here ...
    })
    .catch((rejRes) => {
      if (rejRes instanceof Error) {
        // Some Redis error
        // Never happen if `insuranceLimiter` set up
        // Decide what to do with it in other case
      } else {
        // Can't consume
        // If there is no error, rateLimiterRedis promise rejected with number of ms before next request allowed
        const secs = Math.round(rejRes.msBeforeNext / 1000) || 1;
        res.set('Retry-After', String(secs));
        res.status(429).send('Too Many Requests');
      }
    });

See all options here

RateLimiterRedis benchmark

Endpoint is pure NodeJS endpoint launched in node:10.5.0-jessie and redis:4.0.10-alpine Docker containers by PM2 with 4 workers

By bombardier -c 1000 -l -d 30s -r 2000 -t 5s http://127.0.0.1:8000

Test with 1000 concurrent requests with maximum 2000 requests per sec during 30 seconds

Statistics        Avg      Stdev        Max
  Reqs/sec      2015.20     511.21   14570.19
  Latency        2.45ms     7.51ms   138.41ms
  Latency Distribution
     50%     1.95ms
     75%     2.16ms
     90%     2.43ms
     95%     2.77ms
     99%     5.73ms
  HTTP codes:
    1xx - 0, 2xx - 53556, 3xx - 0, 4xx - 6417, 5xx - 0

Heap snapshot statistic on high traffic