ExponentialWithJitterBackoff

Implements exponential backoff with random jitter to avoid thundering herd problems in retry scenarios.

class ExponentialWithJitterBackoff(AbstractBackoff):
    """Exponential backoff upon failure, with jitter"""

    def __init__(self, cap: float = DEFAULT_CAP, base: float = DEFAULT_BASE) -> None:
        """
        `cap`: maximum backoff time in seconds
        `base`: base backoff time in seconds
        """
        self._cap = cap
        self._base = base

    def __hash__(self) -> int:
        return hash((self._base, self._cap))

    def __eq__(self, other) -> bool:
        if not isinstance(other, ExponentialWithJitterBackoff):
            return NotImplemented

        return self._base == other._base and self._cap == other._cap

    def compute(self, failures: int) -> float:
        return min(self._cap, random.random() * self._base * 2**failures)