Files
edx-platform/lms/djangoapps/course_api/blocks/tests/test_api.py
connorhaugh b01e773d2b feat: cache course index queries (#29107)
* feat: store split modulestore's course indexes in Django/MySQL

Course outline generation is calling active_versions hundreds or even thousands of times on course_publish. In practice, the handling of a block requires a fetch of the course index. That requires a call to the active_versions table for each touching of a block. In larger courses, that can mean 1000s of calls to the db to retrieve them. A quick solution to this problem is to use a request cache, so we don't have to query the slow db every time and memoize the relevant data
[An example run can be seen here.](https://one.newrelic.com/launcher/nr1-core.explorer?platform[filters]=IihuYW1lIGxpa2UgJ3Byb2QtZWR4LWVkeGFwcCcgb3IgaWQgPSAncHJvZC1lZHgtZWR4YXBwJyBvciBkb21haW5JZCA9ICdwcm9kLWVkeC1lZHhhcHAnKSBhbmQgKG5hbWUgbGlrZSAnbG1zJyBvciBpZCA9ICdsbXMnIG9yIGRvbWFpbklkID0gJ2xtcycpIg==&platform[accountId]=88178&platform[timeRange][begin_time]=1626715880701&platform[timeRange][end_time]=1627320680701&pane=eyJuZXJkbGV0SWQiOiJhcG0tbmVyZGxldHMudHJhbnNhY3Rpb25zIiwiZW50aXR5R3VpZCI6Ik9EZ3hOemg4UVZCTmZFRlFVRXhKUTBGVVNVOU9mRFk1TVRNM05EUTROQSIsInNlbGVjdGVkU2VyaWVzIjoiZjAzYjNmNzY5OTQ0MjlmOTFhYWQ4MDBkNTEwZTU5MDM5OWNjMzNhMSIsImRyaWxsZG93biI6eyJ0cmFuc2FjdGlvbk5hbWUiOiJPdGhlclRyYW5zYWN0aW9uL0NlbGVyeS9jbXMuZGphbmdvYXBwcy5jb250ZW50c3RvcmUudGFza3MudXBkYXRlX291dGxpbmVfZnJvbV9tb2R1bGVzdG9yZV90YXNrIn19&cards[0]=eyJuZXJkbGV0SWQiOiJhcG0tbmVyZGxldHMudHJhbnNhY3Rpb24tdHJhY2UiLCJ0cmFjZUlkIjoiY2I2OGNkMDktZWI5Yi0xMWViLWJkY2QtMDI0MmFjMTEwMDBlXzI1MjU0MV8zMTgzMTMiLCJlbnRpdHlHdWlkIjoiT0RneE56aDhRVkJOZkVGUVVFeEpRMEZVU1U5T2ZEWTVNVE0zTkRRNE5BIn0=&sidebars[0]=eyJuZXJkbGV0SWQiOiJucjEtY29yZS5hY3Rpb25zIiwic2VsZWN0ZWROZXJkbGV0Ijp7Im5lcmRsZXRJZCI6ImFwbS1uZXJkbGV0cy50cmFuc2FjdGlvbnMifSwiZW50aXR5R3VpZCI6Ik9EZ3hOemg4UVZCTmZFRlFVRXhKUTBGVVNVOU9mRFk1TVRNM05EUTROQSJ9&state=d9946155-ea53-cb11-c1c0-cc873d6c7d39)

Useful information to include:
In theory, this should provide a minor performance boost to authors and learners, and be noticeable in the above function trace, once live on prod. Note, that in several places the cache must be invalidated, as to prevent a stale cache.


Co-authored-by: Braden MacDonald <braden@opencraft.com>
2021-10-27 13:53:10 -04:00

243 lines
9.2 KiB
Python

"""
Tests for Blocks api.py
"""
from itertools import product
from unittest.mock import patch
import ddt
from django.test.client import RequestFactory
from edx_toggles.toggles.testutils import override_waffle_switch
from common.djangoapps.student.tests.factories import UserFactory
from openedx.core.djangoapps.content.block_structure.api import clear_course_from_cache
from openedx.core.djangoapps.content.block_structure.config import STORAGE_BACKING_FOR_CACHE
from xmodule.modulestore import ModuleStoreEnum
from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
from xmodule.modulestore.tests.factories import SampleCourseFactory, check_mongo_calls
from xmodule.modulestore.tests.sample_courses import BlockInfo
from ..api import get_blocks
class TestGetBlocks(SharedModuleStoreTestCase):
"""
Tests for the get_blocks function
"""
@classmethod
def setUpClass(cls):
super().setUpClass()
with cls.store.default_store(ModuleStoreEnum.Type.split):
cls.course = SampleCourseFactory.create()
# hide the html block
cls.html_block = cls.store.get_item(cls.course.id.make_usage_key('html', 'html_x1a_1'))
cls.html_block.visible_to_staff_only = True
cls.store.update_item(cls.html_block, ModuleStoreEnum.UserID.test)
def setUp(self):
super().setUp()
self.user = UserFactory.create()
self.request = RequestFactory().get("/dummy")
self.request.user = self.user
def test_basic(self):
blocks = get_blocks(self.request, self.course.location, self.user)
assert blocks['root'] == str(self.course.location)
# subtract for (1) the orphaned course About block and (2) the hidden Html block
assert len(blocks['blocks']) == (len(self.store.get_items(self.course.id)) - 2)
assert str(self.html_block.location) not in blocks['blocks']
def test_no_user(self):
blocks = get_blocks(self.request, self.course.location)
assert str(self.html_block.location) in blocks['blocks']
def test_access_before_api_transformer_order(self):
"""
Tests the order of transformers: access checks are made before the api
transformer is applied.
"""
blocks = get_blocks(self.request, self.course.location, self.user, nav_depth=5, requested_fields=['nav_depth'])
vertical_block = self.store.get_item(self.course.id.make_usage_key('vertical', 'vertical_x1a'))
problem_block = self.store.get_item(self.course.id.make_usage_key('problem', 'problem_x1a_1'))
vertical_descendants = blocks['blocks'][str(vertical_block.location)]['descendants']
assert str(problem_block.location) in vertical_descendants
assert str(self.html_block.location) not in vertical_descendants
def test_sub_structure(self):
sequential_block = self.store.get_item(self.course.id.make_usage_key('sequential', 'sequential_y1'))
blocks = get_blocks(self.request, sequential_block.location, self.user)
assert blocks['root'] == str(sequential_block.location)
assert len(blocks['blocks']) == 5
for block_type, block_name, is_inside_of_structure in (
('vertical', 'vertical_y1a', True),
('problem', 'problem_y1a_1', True),
('chapter', 'chapter_y', False),
('sequential', 'sequential_x1', False),
):
block = self.store.get_item(self.course.id.make_usage_key(block_type, block_name))
if is_inside_of_structure:
assert str(block.location) in blocks['blocks']
else:
assert str(block.location) not in blocks['blocks']
def test_filtering_by_block_types(self):
sequential_block = self.store.get_item(self.course.id.make_usage_key('sequential', 'sequential_y1'))
# not filtered blocks
blocks = get_blocks(self.request, sequential_block.location, self.user, requested_fields=['type'])
assert len(blocks['blocks']) == 5
found_not_problem = False
for block in blocks['blocks'].values():
if block['type'] != 'problem':
found_not_problem = True
assert found_not_problem
# filtered blocks
blocks = get_blocks(self.request, sequential_block.location, self.user,
block_types_filter=['problem'], requested_fields=['type'])
assert len(blocks['blocks']) == 3
for block in blocks['blocks'].values():
assert block['type'] == 'problem'
class TestGetBlocksVideoUrls(SharedModuleStoreTestCase):
"""
Tests the video blocks returned have their URL re-written for
encoded videos.
"""
@classmethod
def setUpClass(cls):
super().setUpClass()
with cls.store.default_store(ModuleStoreEnum.Type.split):
cls.course = SampleCourseFactory.create(
block_info_tree=[
BlockInfo('empty_chapter', 'chapter', {}, [
BlockInfo('empty_sequential', 'sequential', {}, [
BlockInfo('empty_vertical', 'vertical', {}, []),
]),
]),
BlockInfo('full_chapter', 'chapter', {}, [
BlockInfo('full_sequential', 'sequential', {}, [
BlockInfo('full_vertical', 'vertical', {}, [
BlockInfo('html', 'html', {}, []),
BlockInfo('sample_video', 'video', {}, [])
]),
]),
])
]
)
def setUp(self):
super().setUp()
self.user = UserFactory.create()
self.request = RequestFactory().get("/dummy")
self.request.user = self.user
@patch('xmodule.video_module.VideoBlock.student_view_data')
def test_video_urls_rewrite(self, video_data_patch):
"""
Verify the video blocks returned have their URL re-written for
encoded videos.
"""
video_data_patch.return_value = {
'encoded_videos': {
'hls': {
'url': 'https://xyz123.cloudfront.net/XYZ123ABC.mp4',
'file_size': 0
},
'mobile_low': {
'url': 'https://1234abcd.cloudfront.net/ABCD1234abcd.mp4',
'file_size': 0
}
}
}
blocks = get_blocks(
self.request, self.course.location, requested_fields=['student_view_data'], student_view_data=['video']
)
video_block_key = str(self.course.id.make_usage_key('video', 'sample_video'))
video_block_data = blocks['blocks'][video_block_key]
for video_data in video_block_data['student_view_data']['encoded_videos'].values():
assert 'cloudfront' not in video_data['url']
@ddt.ddt
class TestGetBlocksQueryCountsBase(SharedModuleStoreTestCase):
"""
Base for the get_blocks tests.
"""
ENABLED_SIGNALS = ['course_published']
def setUp(self):
super().setUp()
self.user = UserFactory.create()
self.request = RequestFactory().get("/dummy")
self.request.user = self.user
def _create_course(self, store_type):
"""
Creates the sample course in the given store type.
"""
with self.store.default_store(store_type):
return SampleCourseFactory.create()
def _get_blocks(self, course, expected_mongo_queries, expected_sql_queries):
"""
Verifies the number of expected queries when calling
get_blocks on the given course.
"""
with check_mongo_calls(expected_mongo_queries):
with self.assertNumQueries(expected_sql_queries):
get_blocks(self.request, course.location, self.user)
@ddt.ddt
class TestGetBlocksQueryCounts(TestGetBlocksQueryCountsBase):
"""
Tests query counts for the get_blocks function.
"""
@ddt.data(
*product(
(ModuleStoreEnum.Type.mongo, ModuleStoreEnum.Type.split),
(True, False),
)
)
@ddt.unpack
def test_query_counts_cached(self, store_type, with_storage_backing):
with override_waffle_switch(STORAGE_BACKING_FOR_CACHE, active=with_storage_backing):
course = self._create_course(store_type)
self._get_blocks(
course,
expected_mongo_queries=0,
expected_sql_queries=14 if with_storage_backing else 13,
)
@ddt.data(
(ModuleStoreEnum.Type.mongo, 5, True, 24),
(ModuleStoreEnum.Type.mongo, 5, False, 14),
(ModuleStoreEnum.Type.split, 2, True, 24),
(ModuleStoreEnum.Type.split, 2, False, 14),
)
@ddt.unpack
def test_query_counts_uncached(self, store_type, expected_mongo_queries, with_storage_backing, num_sql_queries):
with override_waffle_switch(STORAGE_BACKING_FOR_CACHE, active=with_storage_backing):
course = self._create_course(store_type)
clear_course_from_cache(course.id)
self._get_blocks(
course,
expected_mongo_queries,
expected_sql_queries=num_sql_queries,
)