def test_calculate_backoff(self):
sec = utils.calculate_backoff(0, 10, 2, 0)
self.assertEqual(sec, 0)
sec = utils.calculate_backoff(9, 10, 2, 0)
self.assertEqual(sec, 1.8)
sec = utils.calculate_backoff(4, 10, 2, 0)
self.assertEqual(sec, 0.8)
sec = utils.calculate_backoff(4, 10, 2, 1)
if sec != 0.8:
self.assertThat(sec, matchers.GreaterThan(0.8))
self.assertThat(sec, matchers.LessThan(1.8))
self.assertRaises(ValueError, utils.calculate_backoff, 0, 10, -2, -1)
self.assertRaises(ValueError, utils.calculate_backoff, 0, 10, -2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, 0, 10, 2, -1)
self.assertRaises(ValueError, utils.calculate_backoff, -2, -10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, 2, -10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, -2, 10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, -1, 10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, 10, 10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, 11, 10, 2, 0)
def test_calculate_backoff(self):
sec = utils.calculate_backoff(0, 10, 2, 0)
self.assertEqual(sec, 0)
sec = utils.calculate_backoff(9, 10, 2, 0)
self.assertEqual(sec, 1.8)
sec = utils.calculate_backoff(4, 10, 2, 0)
self.assertEqual(sec, 0.8)
sec = utils.calculate_backoff(4, 10, 2, 1)
if sec != 0.8:
self.assertThat(sec, matchers.GreaterThan(0.8))
self.assertThat(sec, matchers.LessThan(1.8))
self.assertRaises(ValueError, utils.calculate_backoff, 0, 10, -2, -1)
self.assertRaises(ValueError, utils.calculate_backoff, 0, 10, -2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, 0, 10, 2, -1)
self.assertRaises(ValueError, utils.calculate_backoff, -2, -10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, 2, -10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, -2, 10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, -1, 10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, 10, 10, 2, 0)
self.assertRaises(ValueError, utils.calculate_backoff, 11, 10, 2, 0)
def _backoff_sleep(self, attempt):
"""Sleep between retries using a jitter algorithm.
Mitigates thrashing between multiple parallel requests, and
creates backpressure on clients to slow down the rate
at which they submit requests.
:param attempt: current attempt number, zero-based
"""
conf = self.driver.mongodb_conf
seconds = utils.calculate_backoff(attempt, conf.max_attempts, conf.max_retry_sleep, conf.max_retry_jitter)
time.sleep(seconds)
def _backoff_sleep(self, attempt):
"""Sleep between retries using a jitter algorithm.
Mitigates thrashing between multiple parallel requests, and
creates backpressure on clients to slow down the rate
at which they submit requests.
:param attempt: current attempt number, zero-based
"""
conf = self.driver.mongodb_conf
seconds = utils.calculate_backoff(attempt, conf.max_attempts,
conf.max_retry_sleep,
conf.max_retry_jitter)
time.sleep(seconds)