def test_calculate_2_shards_against_optimal_shards(self):
for _ in range(100):
random.seed(120)
random_times = {k: random.random() * 10 for k in self.tests}
# all test times except first two
rest_of_tests = [
i for k, i in random_times.items()
if k != 'super_long_test' and k != 'long_test1'
]
sum_of_rest = sum(rest_of_tests)
random_times['super_long_test'] = max(sum_of_rest / 2,
max(rest_of_tests))
random_times[
'long_test1'] = sum_of_rest - random_times['super_long_test']
# An optimal sharding would look like the below, but we don't need to compute this for the test:
# optimal_shards = [
# (sum_of_rest, ['super_long_test', 'long_test1']),
# (sum_of_rest, [i for i in self.tests if i != 'super_long_test' and i != 'long_test1']),
# ]
calculated_shards = calculate_shards(2, self.tests, random_times)
max_shard_time = max(calculated_shards[0][0],
calculated_shards[1][0])
if sum_of_rest != 0:
# The calculated shard should not have a ratio worse than 7/6 for num_shards = 2
self.assertGreaterEqual(7.0 / 6.0,
max_shard_time / sum_of_rest)
sorted_tests = sorted(self.tests)
sorted_shard_tests = sorted(calculated_shards[0][1] +
calculated_shards[1][1])
# All the tests should be represented by some shard
self.assertEqual(sorted_tests, sorted_shard_tests)
def test_calculate_2_shards_with_incomplete_test_times(self):
incomplete_test_times = {k: v for k, v in self.test_times.items() if 'test1' in k}
expected_shards = [
(22, ['long_test1', 'long_test2', 'normal_test3', 'short_test3', 'short_test5']),
(10, ['normal_test1', 'short_test1', 'super_long_test', 'normal_test2', 'short_test2', 'short_test4']),
]
self.assertEqual(expected_shards, calculate_shards(2, self.tests, incomplete_test_times))
def test_calculate_2_shards_with_complete_test_times(self):
expected_shards = [
(60, ['super_long_test', 'normal_test3']),
(58.31, ['long_test1', 'long_test2', 'normal_test1', 'normal_test2', 'short_test1', 'short_test2',
'short_test3', 'short_test4', 'short_test5'])
]
self.assertEqual(expected_shards, calculate_shards(2, self.tests, self.test_times))
def test_calculate_5_shards_with_complete_test_times(self):
expected_shards = [
(55, ['super_long_test']),
(22, ['long_test1', ]),
(18, ['long_test2', ]),
(11.31, ['normal_test1', 'short_test1', 'short_test2', 'short_test3', 'short_test4', 'short_test5']),
(12, ['normal_test2', 'normal_test3']),
]
self.assertEqual(expected_shards, calculate_shards(5, self.tests, self.test_times))
def get_shard(which_shard: int, num_shards: int, tests: List[str]) -> List[str]:
jobs_to_times = get_past_job_times()
# Got no stats from S3, returning early to save runtime
if len(jobs_to_times) == 0:
print('Gathered no stats from S3. Proceeding with default sharding plan.')
return tests[which_shard - 1 :: num_shards]
shards = calculate_shards(num_shards, tests, jobs_to_times)
_, tests_from_shard = shards[which_shard - 1]
return tests_from_shard
