Function get_exponential_backoff_interval

celery/utils/time.py:448–462

Calculate the exponential backoff wait time.

(
    factor: int,
    retries: int,
    maximum: int,
    full_jitter: bool = False
)

def get_exponential_backoff_interval(
    factor: int,
    retries: int,
    maximum: int,
    full_jitter: bool = False
) -> int:
    """Calculate the exponential backoff wait time."""
    # Will be zero if factor equals 0
    countdown = min(maximum, factor * (2 ** retries))
    # Full jitter according to
    # https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/
    if full_jitter:
        countdown = random.randrange(countdown + 1)
    # Adjust according to maximum wait time and account for negative values.
    return max(0, countdown)