Request rate limiter mok implementation.

requester.js

// libs
const request = require('request');
const {RateLimiter} = require('limiter');

// config
const pool = {maxSockets: 100};
const url = 'http://google.com';
const numRequests = 10000;
const requestLimit = 5000;
const limiter = new RateLimiter(requestLimit, 'hour');
let completed = 0;

// request function
function doRequest(){
  return new Promise((good, bad) => {
    request({url , pool}, (err, res) => err? bad(err) : good(res));
  };
}

// limited request function
function doLimitedRequest(){
  limiter.removeTokens(1, function(err, remaining) {
    const timestamp = (new Date()).toTimeString().split(' ')[0];
    doRequest().then(() => {
      completed++;
      if(completed % 100 === 0) console.log(timestamp + ' completed: ' + ~~completed);
    });
  });
}

// run the requests
for(let i=0; i<numRequests; i++){
  doLimitedRequest();
}

Install dependencies with yarn add request limiter and run the script with node requester.js