I need a component/class that throttles execution of some method to maximum M calls in N seconds (or ms or nanos, does not matter).
In other words I need to make sure that my method is executed no more than M times in a sliding window of N seconds.
If you don't know existing class feel free to post your solutions/ideas how you would implement this.
Read up on the Token bucket algorithm. Basically, you have a bucket with tokens in it. Every time you execute the method, you take a token. If there are no more tokens, you block until you get one. Meanwhile, there is some external actor that replenishes the tokens at a fixed interval.
I'm not aware of a library to do this (or anything similar). You could write this logic into your code or use AspectJ to add the behavior.
I'd use a ring buffer of timestamps with a fixed size of M. Each time the method is called, you check the oldest entry, and if it's less than N seconds in the past, you execute and add another entry, otherwise you sleep for the time difference.
In concrete terms, you should be able to implement this with a DelayQueue. Initialize the queue with M Delayed instances with their delay initially set to zero. As requests to the method come in, take a token, which causes the method to block until the throttling requirement has been met. When a token has been taken, add a new token to the queue with a delay of N.
Although it's not what you asked, ThreadPoolExecutor, which is designed to cap to M simultaneous requests instead of M requests in N seconds, could also be useful.
I need to make sure that my method is executed no more than M times in a sliding window of N seconds.
I recently wrote a blog post about how to do this in .NET. You might be able to create something similar in Java.