6a8f50bb91
Calculates an exponential backoff delay with jitter for retrying operations which might fail. The exponential delay on each attempt gives the service a chance to process its backlog of retries after it starts responding again. The jitter adds some randomness to the delay to prevent multiple synchronised backoff retries from hitting the service at exactly the same time. The next change in this series makes use of this function. Change-Id: Ie209ef62c0da68a5b503354764e5add2b6e5569a
145 lines
4.1 KiB
Python
145 lines
4.1 KiB
Python
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
from testtools import matchers
|
|
|
|
from heat.common import timeutils as util
|
|
from heat.tests.common import HeatTestCase
|
|
|
|
|
|
class ISO8601UtilityTest(HeatTestCase):
|
|
|
|
def setUp(self):
|
|
super(ISO8601UtilityTest, self).setUp()
|
|
|
|
def test_valid_durations(self):
|
|
self.assertEqual(0, util.parse_isoduration('PT'))
|
|
self.assertEqual(3600, util.parse_isoduration('PT1H'))
|
|
self.assertEqual(120, util.parse_isoduration('PT2M'))
|
|
self.assertEqual(3, util.parse_isoduration('PT3S'))
|
|
self.assertEqual(3900, util.parse_isoduration('PT1H5M'))
|
|
self.assertEqual(3605, util.parse_isoduration('PT1H5S'))
|
|
self.assertEqual(303, util.parse_isoduration('PT5M3S'))
|
|
self.assertEqual(3903, util.parse_isoduration('PT1H5M3S'))
|
|
self.assertEqual(24 * 3600, util.parse_isoduration('PT24H'))
|
|
|
|
def test_invalid_durations(self):
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'P1Y')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'P1DT12H')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'PT1Y1D')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'PTAH1M0S')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'PT1HBM0S')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'PT1H1MCS')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'PT1H1H')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'PT1MM')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'PT1S0S')
|
|
self.assertRaises(ValueError, util.parse_isoduration, 'ABCDEFGH')
|
|
|
|
|
|
class RetryBackoffExponentialTest(HeatTestCase):
|
|
|
|
scenarios = [(
|
|
'0_0',
|
|
dict(
|
|
attempt=0,
|
|
scale_factor=0.0,
|
|
delay=0.0,
|
|
)
|
|
), (
|
|
'0_1',
|
|
dict(
|
|
attempt=0,
|
|
scale_factor=1.0,
|
|
delay=1.0,
|
|
)
|
|
), (
|
|
'1_1',
|
|
dict(
|
|
attempt=1,
|
|
scale_factor=1.0,
|
|
delay=2.0,
|
|
)
|
|
), (
|
|
'2_1',
|
|
dict(
|
|
attempt=2,
|
|
scale_factor=1.0,
|
|
delay=4.0,
|
|
)
|
|
), (
|
|
'3_1',
|
|
dict(
|
|
attempt=3,
|
|
scale_factor=1.0,
|
|
delay=8.0,
|
|
)
|
|
), (
|
|
'4_1',
|
|
dict(
|
|
attempt=4,
|
|
scale_factor=1.0,
|
|
delay=16.0,
|
|
)
|
|
), (
|
|
'4_4',
|
|
dict(
|
|
attempt=4,
|
|
scale_factor=4.0,
|
|
delay=64.0,
|
|
)
|
|
)]
|
|
|
|
def test_backoff_delay(self):
|
|
delay = util.retry_backoff_delay(
|
|
self.attempt, self.scale_factor)
|
|
self.assertEqual(delay, self.delay)
|
|
|
|
|
|
class RetryBackoffJitterTest(HeatTestCase):
|
|
|
|
scenarios = [(
|
|
'0_0_1',
|
|
dict(
|
|
attempt=0,
|
|
scale_factor=0.0,
|
|
jitter_max=1.0,
|
|
delay_from=0.0,
|
|
delay_to=1.0
|
|
)
|
|
), (
|
|
'1_1_1',
|
|
dict(
|
|
attempt=1,
|
|
scale_factor=1.0,
|
|
jitter_max=1.0,
|
|
delay_from=2.0,
|
|
delay_to=3.0
|
|
)
|
|
), (
|
|
'1_1_5',
|
|
dict(
|
|
attempt=1,
|
|
scale_factor=1.0,
|
|
jitter_max=5.0,
|
|
delay_from=2.0,
|
|
delay_to=7.0
|
|
)
|
|
)]
|
|
|
|
def test_backoff_delay(self):
|
|
for _ in range(100):
|
|
delay = util.retry_backoff_delay(
|
|
self.attempt, self.scale_factor, self.jitter_max)
|
|
self.assertThat(delay, matchers.GreaterThan(self.delay_from))
|
|
self.assertThat(delay, matchers.LessThan(self.delay_to))
|