alexdelorenzo / limiter Goto Github PK

I'm having a hard time understanding jitter as it relates to my other params.

According to Base, DEFAULT_JITTER: = False, and it doesn't seem like DEFAULT_JITTER is ever updated when I call a new Limiter(). I know I can set it as an arg with Limiter(jitter=X).

I also saw in Base in the definition for _get_sleep_duration

def _get_sleep_duration(
  consume: Tokens,
  tokens: Tokens,
  rate: Tokens,
  jitter: Jitter = DEFAULT_JITTER,
  units: UnitsInSecond = MS_IN_SEC
) -> Duration:
  """Increase contention by adding jitter to sleep duration"""
  duration: Duration = (consume - tokens) / rate
  
  match jitter:
    case int() | float():
      return duration - jitter
 
    case bool() if jitter:
      amount: Duration = random() / units
      return duration - amount

  return duration

It's clear that jitter can be a bool, int, or float, but I don't really understand how I should size it with respect to my consume or rate values. I don't want to add too much jitter that it ends up overpowering my sleep duration and I end up with a negative number.

Let's say I have these params:

• rate = 20 # replenish tokens per second
• consume = 1 # because I want my function to be allowed to run a maximum of 20 times per second
• capacity = 300 # because I want my function to be able to run for 15 seconds maximum before it gets limited (function can't get called more than 300 times per minute max)

But according to the _get_sleep_duration calculation, my duration = (1 - 300) / 20 = -14.95 and so I'm already at a negative number.

• Am I thinking about my params correctly?
• What's the right way to add jitter as a param?

I couldn't figure out what the parameter 'consume' meant, it would be great if the readme elaborated some more on that. "The amount of tokens to consume dynamically" - sorry I have no idea what this means. Thank you!

0.3.0 will break pretty much all of it's consumers if they haven't pinned the release. The changelog simply says "Update API".

ImportError: cannot import name 'get_limiter' from 'limiter'