This is an issue related to the caching of course blocks and how we utilize the course blocks cache during the update of persistent grades.
Steps to Reproduce
Here are the steps to reproduce this locally.
- Create a course with multiple subsections and add some problems.
- Some of the subsections should be restricted to the Verified learners.
- Create a new learner and enroll in Audit Mode.
- Access the course with the Audit Learner
- Visit some of the subsections and verify that the restricted subsection content is not accessible.
- Attempt the problems, and verify the grades on the Progress page.
- Create a new learner and enroll in verified mode.
- Access the restricted subsection.
- Attempt problems. Submissions are successful but grades are not updated on the Progress page.
Temporary Fix
It can be fixed by clearing the course cache and then attempting a new problem or rescoring the restricted problem. The course cache can be cleared by running this code snippet. Once the cache is cleared, Verified learners can attempt a new problem and verify the submission on the Progress page.
from opaque_keys.edx.locator import CourseLocator
from xmodule.modulestore.django import modulestore
store = modulestore()
course_key = CourseLocator.from_string("REPLACE WITH COURSE ID")
from openedx.core.djangoapps.content.block_structure.store import BlockStructureStore
from django.core.cache import cache
BlockStructureStore(cache).delete(store.make_course_usage_key(course_key))
Another Fix: Change the Grading Policy
Another workaround to fix the issue is to change the grading policy. This was identified by the course teams as they noticed that when the grading policy changes, all of the grades are updated successfully.
While looking at the code that updates the grades on policy change, we have identified that it does not use the cached blocks.
THE ISSUE
Here is the code for _update_subsection_grades
def _update_subsection_grades(
course_key, scored_block_usage_key, only_if_higher, user_id, score_deleted, force_update_subsections=False
):
"""
A helper function to update subsection grades in the database
for each subsection containing the given block, and to signal
that those subsection grades were updated.
"""
student = User.objects.get(id=user_id)
store = modulestore()
with store.bulk_operations(course_key):
course_structure = get_course_blocks(student, store.make_course_usage_key(course_key))
subsections_to_update = course_structure.get_transformer_block_field(
scored_block_usage_key,
GradesTransformer,
'subsections',
set(),
)
course = store.get_course(course_key, depth=0)
subsection_grade_factory = SubsectionGradeFactory(student, course, course_structure)
for subsection_usage_key in subsections_to_update:
if subsection_usage_key in course_structure:
subsection_grade = subsection_grade_factory.update(
course_structure[subsection_usage_key],
only_if_higher,
score_deleted,
force_update_subsections,
)
SUBSECTION_SCORE_CHANGED.send(
sender=None,
course=course,
course_structure=course_structure,
user=student,
subsection_grade=subsection_grade,
)
In the above code snippet, when course_structure does not contain the restricted blocks then subsections_to_update is an empty set. Hence, it won’t make a call to subsection_grade_factory.update
What happens when the Grading Policy is Changed?
Any Permanent Fix?
I am not sure about a permanent fix to this issue as I need to look more into it.