Checker: Distribute checks among the tick more randomly

fausecteam / ctf-gameserver

FAUST Gameserver for attack-defense CTFs

https://ctf-gameserver.org

ISC License

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Checker: Distribute checks among the tick more randomly #27

Closed F30 closed 4 years ago

F30 commented 6 years ago

Gameserver fingerprinting is made easier by the fact that checks are performed at a relatively static point in the tick every n minutes.

This should be more random, however there are some pitfalls:

How do you keep it fair and don't check two times within a minutes and then not for the next almost six minutes or so?
From my understanding, issues as described in #1 are more likely to happen if checks are scheduled later in the tick.

F30 commented 4 years ago

This was clearly improved with the Checker rewrite. The behavior is still not ideal, e.g. no checks are expected to run during the last 1/6 of a Tick. But that is hard to fix given all the fuzziness and imponderables regarding how long a check takes.

If we're gonna change something about check scheduling again, I assume it will be in the form of #10.