rate control in java

Question

I am looking for a good solution or probably an API to solve the following problem:

My application does a task in a loop, for example it sends e-mails etc. I need to limit the average rate of messages to for example 100 messages per second or 1000 messages per last minute ...

No I am looking for an algorithm or an API which does exactly this task.

Is this to avoid raising alarms in SpamBots? – Andrew Thompson Sep 08 '11 at 15:00 — Andrew Thompson, Sep 08 '11 at 15:00

score 4 · Answer 1 · answered Sep 08 '11 at 14:48

4

You can use a ScheduledExecutorService to schedule tasks for a given period of time.

For example, to schedule 100 tasks per second you can say:

ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(nThreads);
scheduler.scheduleAtFixedRate(mailSender, 0, 10, TimeUnit.MILLISECONDS);

Obviously, you need to track how many tasks have executed and turn off the scheduler after the job is done.

answered Sep 08 '11 at 14:48

dm3

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Or have the scheduled task not do anything when there is nothing left to do. This avoids having to cancel and add it repeatedly. – Peter Lawrey Sep 08 '11 at 15:00

score 4 · Answer 2 · answered Sep 08 '11 at 14:49

4

Token bucket algorithm is very easy to implement and use yet very powerful. You can control the throughput at runtime and queue some requests to handle peeks.

answered Sep 08 '11 at 14:49

Tomasz Nurkiewicz

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score 3 · Answer 3 · edited Feb 12 '18 at 07:04

3

Guava has a RateLimiter class that does exactly that.

edited Feb 12 '18 at 07:04

Shailendra

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answered Jun 06 '13 at 12:07

mR_fr0g

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Fixed dead link – Shailendra Feb 12 '18 at 07:05

score 3 · Answer 4 · edited Aug 20 '14 at 17:53

3

The simplest way I can think of is to delay when to send each emails depending on how many are waiting.

final ScheduledThreadPoolExecutor service = new ScheduledThreadPoolExecutor(1);
int ratePerSecond = ...

public static void execute(Runnable run) {
   int delay = 1000 * service.getQueue().size() / ratePerSecond;
   service.schedule(run, delay, TimeUnit.MILLISECONDS);
}

This will ensure that the tasks are performed only as close to together as the rate allows.

edited Aug 20 '14 at 17:53

Paulo Fidalgo

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answered Sep 08 '11 at 15:07

Peter Lawrey

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I think its important to be simple enough that you can easily understand how its going to work. There are more sophisticated solutions but you probably don't need them. – Peter Lawrey Sep 09 '11 at 06:58
Nice - simple and elegant! – Mark Hansen Feb 28 '13 at 20:42

rate control in java

4 Answers4

Linked