node-rate-limiter-flexible
rate-limiter-flexible counts and limits number of actions by key and protects from DDoS and brute force attacks at any scale.
It works with Redis, process Memory, Cluster or PM2, Memcached, MongoDB, MySQL, PostgreSQL and allows to control requests rate in single process or distributed environment.
Atomic increments. All operations in memory or distributed environment use atomic increments against race conditions.
Fast. Average request takes 0.7ms
in Cluster and 2.5ms
in Distributed application. See benchmarks.
Flexible. Combine limiters, block key for some duration, delay actions, manage failover with insurance options, configure smart key blocking in memory and many others.
Ready for growth. It provides unified API for all limiters. Whenever your application grows, it is ready. Prepare your limiters in minutes.
Friendly. No matter which node package you prefer: redis
or ioredis
, sequelize
or knex
, memcached
, native driver or mongoose
. It works with all of them.
It uses fixed window as it is much faster than rolling window.
See comparative benchmarks with other libraries here
Installation
npm i --save rate-limiter-flexible
yarn add rate-limiter-flexible
Basic Example
const opts = {
points: 6,
duration: 1,
};
const rateLimiter = new RateLimiterMemory(opts);
rateLimiter.consume(remoteAddress, 2)
.then((rateLimiterRes) => {
})
.catch((rateLimiterRes) => {
});
RateLimiterRes object
Both Promise resolve and reject return object of RateLimiterRes
class if there is no any error.
Object attributes:
RateLimiterRes = {
msBeforeNext: 250,
remainingPoints: 0,
consumedPoints: 5,
isFirstInDuration: false,
}
You may want to set next HTTP headers to response:
const headers = {
"Retry-After": rateLimiterRes.msBeforeNext / 1000,
"X-RateLimit-Limit": opts.points,
"X-RateLimit-Remaining": rateLimiterRes.remainingPoints,
"X-RateLimit-Reset": new Date(Date.now() + rateLimiterRes.msBeforeNext)
}
Advantages:
Middlewares and plugins
Some copy/paste examples on Wiki:
Migration from other packages
- express-brute Bonus: race conditions fixed, prod deps removed
- limiter Bonus: multi-server support, respects queue order, native promises
Docs and Examples
Basic Options
-
points
Default: 4
Maximum number of points can be consumed over duration
-
duration
Default: 1
Number of seconds before consumed points are reset.
Never reset points, if duration
is set to 0.
-
storeClient
Required for store limiters
Have to be redis
, ioredis
, memcached
, mongodb
, pg
, mysql2
, mysql
or any other related pool or connection.
Other options on Wiki:
Cut off load picks:
Specific:
API
Read detailed description on Wiki.
Benchmark
Average latency during test pure NodeJS endpoint in cluster of 4 workers with everything set up on one server.
1000 concurrent clients with maximum 2000 requests per sec during 30 seconds.
1. Memory 0.34 ms
2. Cluster 0.69 ms
3. Redis 2.45 ms
4. Memcached 3.89 ms
5. Mongo 4.75 ms
500 concurrent clients with maximum 1000 req per sec during 30 seconds
6. PostgreSQL 7.48 ms (with connection pool max 100)
7. MySQL 14.59 ms (with connection pool 100)
Contribution
Appreciated, feel free!
Make sure you've launched npm run eslint
before creating PR, all errors have to be fixed.
You can try to run npm run eslint-fix
to fix some issues.
Any new limiter with storage have to be extended from RateLimiterStoreAbstract
.
It has to implement at least 4 methods:
_getRateLimiterRes
parses raw data from store to RateLimiterRes
object._upsert
inserts or updates limits data by key and returns raw data._get
returns raw data by key._delete
deletes all key related data and returns true
on deleted, false
if key is not found.
All other methods depends on store. See RateLimiterRedis
or RateLimiterPostgres
for example.