Leaking Bucket

Parameters

• bucketSize, leakRate.

Description

• Requests are queued and processed at a fixed rate, smoothing out traffic spikes.
• Excess requests are dropped if the queue is full.

Example: bucketSize = 4, leakRate = 1 request/2 sec.

• T0 (01:00:00): Bucket empty, 1 request arrives and enters the queue.
• T1 (01:00:02): 1st request processed (leaked out), 3 more arrive and queue up.
• T2 (01:00:03): Requests arrinving at this time are all dropped, because queue if full.
• T3 (01:00:04): 2nd request processed, 2 in queue, new requests continue to queue if space.

How to use

When creating your API, you can use the RateLimitFactory to create a leaking bucket rate limit.

Api.create(8080)
      .rateLimit(RateLimitFactory.customLeakingBucket(4, Duration.ofSeconds(1)))
      .addRoute(Route.builder("/"),
      .path(RouteMethod.GET, "/", controller::handler))
      .start();
          

Factory

The RateLimitFactory provides a default and a custom method for this rate limiter.

• For more details on the check the source code of the RateLimitFactory

See more in our blog post about Rate Limiters