diff options
| -rw-r--r-- | kazoo/retry.py | 38 |
1 files changed, 17 insertions, 21 deletions
diff --git a/kazoo/retry.py b/kazoo/retry.py index eef7fbf..707b378 100644 --- a/kazoo/retry.py +++ b/kazoo/retry.py @@ -1,7 +1,6 @@ import logging import random import time -import warnings from kazoo.exceptions import ( ConnectionClosedError, @@ -43,19 +42,20 @@ class KazooRetry(object): SessionExpiredError, ) - def __init__(self, max_tries=1, delay=0.1, backoff=2, max_jitter=None, - max_delay=60, ignore_expire=True, sleep_func=time.sleep, + def __init__(self, max_tries=1, delay=0.1, backoff=2, max_jitter=0.4, + max_delay=60.0, ignore_expire=True, sleep_func=time.sleep, deadline=None, interrupt=None): """Create a :class:`KazooRetry` instance for retrying function - calls with uniform jitter + calls. :param max_tries: How many times to retry the command. -1 means infinite tries. :param delay: Initial delay between retry attempts. :param backoff: Backoff multiplier between retry attempts. Defaults to 2 for exponential backoff. - :param max_jitter: *Deprecated* Jitter is now uniformly distributed - across retries. + :param max_jitter: Percentage of jitter to apply to each retry's delay + to ensure all clients to do not hammer the server + at the same time. Between 0.0 and 1.0. :param max_delay: Maximum delay in seconds, regardless of other backoff settings. Defaults to one minute. :param ignore_expire: @@ -68,15 +68,11 @@ class KazooRetry(object): between retries. """ - if max_jitter is not None: - warnings.warn( - 'Passing max_jitter to retry configuration is deprecated.' - ' Retry jitter is now automacallity uniform across retries.' - ' The parameter will be ignored.', - DeprecationWarning, stacklevel=2) self.max_tries = max_tries self.delay = delay self.backoff = backoff + # Ensure max_jitter is in (0, 1) + self.max_jitter = max(min(max_jitter, 1.0), 0.0) self.max_delay = float(max_delay) self._attempts = 0 self._cur_delay = delay @@ -99,6 +95,7 @@ class KazooRetry(object): obj = KazooRetry(max_tries=self.max_tries, delay=self.delay, backoff=self.backoff, + max_jitter=self.max_jitter, max_delay=self.max_delay, sleep_func=self.sleep_func, deadline=self.deadline, @@ -134,25 +131,24 @@ class KazooRetry(object): if self._attempts == self.max_tries: raise RetryFailedError("Too many retry attempts") self._attempts += 1 - sleeptime = random.randint(0, 1 + int(self._cur_delay)) + jitter = random.uniform(1.0-self.max_jitter, + 1.0+self.max_jitter) + sleeptime = self._cur_delay * jitter if self._cur_stoptime is not None and \ time.time() + sleeptime >= self._cur_stoptime: raise RetryFailedError("Exceeded retry deadline") if self.interrupt: - while sleeptime > 0: + remain_time = sleeptime + while remain_time > 0: # Break the time period down and sleep for no # longer than 0.1 before calling the interrupt - if sleeptime < 0.1: - self.sleep_func(sleeptime) - sleeptime -= sleeptime - else: - self.sleep_func(0.1) - sleeptime -= 0.1 + self.sleep_func(min(0.1, remain_time)) + remain_time -= 0.1 if self.interrupt(): raise InterruptedError() else: self.sleep_func(sleeptime) - self._cur_delay = min(self._cur_delay * self.backoff, + self._cur_delay = min(sleeptime * self.backoff, self.max_delay) |