Will this work with what I need to do?

[sean-hill]

Hey there

I have a list of 100k emails. I'd like to only send 25 per second. I have setup the code like this:

var async = require('async');
var RateLimiter = require('limiter').RateLimiter;
var limiter = new RateLimiter(25, 'second');

var emails = [];

for (var i = 0; i < 100000; i++) {
    emails.push(i);
};

async.eachSeries(emails, function(email, nextEmail){

    limiter.removeTokens(1, function(err, remainingRequests) {
        asyncEmailFunction(email);
        return nextEmail();
    });

});

// Just as an example
function asyncEmailFunction(email) {
    console.log(email);
};

It works great until about 300 emails, then it just bogs down and doesn't complete them as fast.

[sean-hill]

Haha. I don't even need this module. Here's my solution. 1000ms / 25 = 40ms.

async.eachSeries(emails, function(email, nextEmail){

    setTimeout(function(){
        asyncEmailFunction(email);
        return nextEmail();
    }, 40);

});

[jhurliman]

Glad you worked out a solution. This module is most useful for dealing with unexpected bursts of activity. When you have a known number of tasks that you want to run at a known rate there are easier options like what you pasted above.

[andrewschreiber]

For future reference, here is how you'd approach this with RateLimter (ES6):

import { RateLimiter } from "limiter";

const emails = [...]

const limiter = new RateLimiter(1, 40); // max 1 email per 40 ms

emails.forEach(email  => {
    limiter.removeTokens(1, () => {
        this.sendEmail(email);
    });
});