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    @nabham/limiter

    1.0.4 • Public • Published

    limiter

    An express rate limiting library. Limits requests based on request object property.

    limiter supports in-memory, mongo and redis store with atomicity among multi node processes.

    Installing

    npm install @nabham/limiter
    

    Usage

    var express = require('express');
    var app = express();
    
    var expressLimiter = require('@nabham/limiter');
    expressLimiter.initialize({ type: 'redis' });
    
    var bucket = expressLimiter.bucket({ limit: 10, window: 60 });
    
    app.get('/', bucket, (req, res) => {
      res.send();
    });
    

    Configuration

    limiter support these parameters for initializing configuration.

    Redis store

    {
      type: 'redis'
      store: {
        host: "127.0.0.1",      // Redis server hostname
        port: 6379,             // Redis server port
        db: 3                   // Redis database number
        atomic: true            // If atomicity needed among multi node process
      }
    }
    

    NOTE: Redis store is default store. If store configuration is not passed, it will fallback to default parameters shown above. In case of multi node processes set atomic property in store configuration.

    Memory store

    {
      type: 'memory'
    }
    

    NOTE: Memory store doesn't require any configuration. Memory store does not work well in case of multi worker, as each worker will have its own heap space.

    Mongo store

    {
      type: 'mongo',
      store: {
        url: 'mongodb://localhost:27017'     // Mongodb connection URI
        collectionName: 'limiter'            // Collection name
        dbName: 'ratelimit'                  // Database name
      }
    }
    

    List of all available options under store can be found here. If store configuration is not passed, it will fallback to default parameters shown above.

    NOTE: MongoDB store uses TTL index ( it helps in atomicity ) to set expiry which is monitored by TTL monitor which by default runs every 60 seconds. It might affect correctness of limiter for upto 60 seconds, this might create problem when working with smaller windows. Either use redis, memory store for more granularity or decrease mongodb's TTL monitor frequency

    bucket creation configuration

    Property Default Description
    id connection.remoteAddress Property to be taken from request object. For ex. token, username, connection.remoteAddress ( ip ) . connection.remoteAddress is the path of ip address in express request object. user.id if using passportjs.
    window 60 Time window in seconds in which rate limit will be applied.
    limit Infinity Number of requests allowed in window
    message Too Many Requests Message to be sent to client with 429 error code.

    Strategy

    limiter works on the principle of sliding window algorithm. window in bucket configuration will start counting requests after first request and will reset once window time is over.

    Any suggestion is very much appreciated

    License

    The MIT License

    Install

    npm i @nabham/limiter

    DownloadsWeekly Downloads

    6

    Version

    1.0.4

    License

    MIT

    Unpacked Size

    14.6 kB

    Total Files

    13

    Last publish

    Collaborators

    • nabham