RediBox Throttle

Provides throttle and pThrottle lua scripts for RediBox redis clients.

Installation

npm i redibox-hook-throttle --save

No configuration required.

API

client.throttle(key, limit, seconds)

Args:

• key - key name - ip, user id or some unique key to throttle X by
• limit - limit amount, e.g. '20' requests
• seconds - ttl in secondsof this limit, i.e, '60' - 20 requests per 60 seconds.

Returns:

• ARRAY
• [0] throttled: -> 1 if you should throttle/reject this request, 0 if still within limit
• [1] remaining: -> how many times left until throttled, i.e. 11 requests left
• [2] ttl: -> seconds remaining until limit resets

Example:

In this example we have an express api server and we want to limit each user to no more than 10 requests per minute. We can use throttle in a middleware to achieve this.

const app = express();
 
app.use((req, res, next) => {
  RediBox.client
    .throttle(
      // key based on user id for uniqueness or some other identifier
      `throttle:${req.param('userId')}`,
      // 10 requests
      10, 
      // per 60 seconds
      60
    ).then((result) => {
      const throttled = result[0];
      const remainingRequests = result[1];
      const expiresInSeconds = result[2];
      
      if (throttled) {
        return res.status(429).json({
          msg: `You have made too many requests recently, please try again in ${expiresInSeconds} seconds.`,
        });
      }
      
      // if we want it later on in the request
      req.throttle = {
        remainingRequests,
        expiresInSeconds
      };
      
      // we're all good here so allow user to continue
      next();
    }).catch(next);
});

client.pthrottle(key, limit, milliseconds)

pThrottle is exactly the same as throttle but uses millisecond precision instead of seconds.