Rate limiter for Node.js backed by Redis.
v3.0.2 - #33 by @promag - Use sorted set to limit with moving window.
v2.2.0 - #30 by @kp96 - Race condition when using async.times.
v2.1.3 - #22 by @coderhaoxin - Dev dependencies versions bump.
v2.1.2 - #17 by @waleedsamy - Add Travis CI support.
v2.1.1 - #13 by @kwizzn - Fixes out-of-sync TTLs after running decr().
v2.1.0 - #12 by @luin - Adding support for ioredis.
v2.0.1 - #9 by @ruimarinho - Update redis commands to use array notation.
v2.0.0 - API CHANGE - Change remaining to include current call instead of decreasing it. Decreasing caused an off-by-one problem and caller could not distinguish between last legit call and a rejected call.
- Redis 2.6.12+.
$ npm install ratelimiter
Example Connect middleware implementation limiting against a user._id:
var id = req.user._id;
var limit = new Limiter({ id: id, db: db });
limit.get(function(err, limit){
if (err) return next(err);
res.set('X-RateLimit-Limit', limit.total);
res.set('X-RateLimit-Remaining', limit.remaining - 1);
res.set('X-RateLimit-Reset', limit.reset);
// all good
debug('remaining %s/%s %s', limit.remaining - 1, limit.total, id);
if (limit.remaining) return next();
// not good
var delta = (limit.reset * 1000) - Date.now() | 0;
var after = limit.reset - (Date.now() / 1000) | 0;
res.set('Retry-After', after);
res.send(429, 'Rate limit exceeded, retry in ' + ms(delta, { long: true }));
});total-maxvalueremaining- number of calls left in currentdurationwithout decreasing currentgetreset- time in milliseconds until the end of currentduration
id- the identifier to limit against (typically a user id)db- redis connection instancemax- max requests withinduration[2500]duration- of limit in milliseconds [3600000]
MIT