Revert "Revert ""Update routing config" (#25536)" (#25549)" (#25553)

This reverts commit c1fe3c3a.

cms/celery.py

@@ -10,7 +10,7 @@ import os
 
 from celery import Celery
 
-from openedx.core.lib.celery.routers import AlternateEnvironmentRouter
+from openedx.core.lib.celery.routers import route_task_queue
 
 # set the default Django settings module for the 'celery' program.
 os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'cms.envs.production')
@@ -23,34 +23,12 @@ APP.conf.task_protocol = 1
 APP.config_from_object('django.conf:settings')
 APP.autodiscover_tasks()
 
-# Import after autodiscovery has had a chance to connect to the import_module signal
-# so celery doesn't miss any apps getting installed.
-from django.conf import settings  # pylint: disable=wrong-import-position,wrong-import-order
 
-
-class Router(AlternateEnvironmentRouter):
+def route_task(name, args, kwargs, options, task=None, **kw):  # pylint: disable=unused-argument
     """
-    An implementation of AlternateEnvironmentRouter, for routing tasks to non-cms queues.
+    Celery-defined method allowing for custom routing logic.
+
+    If None is returned from this method, default routing logic is used.
     """
 
-    @property
-    def alternate_env_tasks(self):
-        """
-        Defines alternate environment tasks, as a dict of form { task_name: alternate_queue }
-        """
-        # The tasks below will be routed to the default lms queue.
-        return {
-            'completion_aggregator.tasks.update_aggregators': 'lms',
-            'openedx.core.djangoapps.content.block_structure.tasks.update_course_in_cache': 'lms',
-            'openedx.core.djangoapps.content.block_structure.tasks.update_course_in_cache_v2': 'lms',
-        }
-
-    @property
-    def explicit_queues(self):
-        """
-        Defines specific queues for tasks to run in (typically outside of the cms environment),
-        as a dict of form { task_name: queue_name }.
-        """
-        return {
-            'lms.djangoapps.grades.tasks.compute_all_grades_for_course': settings.POLICY_CHANGE_GRADES_ROUTING_KEY,
-        }
+    return route_task_queue(name)

cms/djangoapps/contentstore/tasks.py

@@ -168,7 +168,7 @@ def _parse_time(time_isoformat):
     ).replace(tzinfo=UTC)
 
 
-@task(routing_key=settings.UPDATE_SEARCH_INDEX_JOB_QUEUE)
+@task
 def update_search_index(course_id, triggered_time_isoformat):
     """ Updates course search index. """
     try:

cms/envs/production.py

@@ -136,7 +136,7 @@ CELERY_QUEUES = {
     DEFAULT_PRIORITY_QUEUE: {}
 }
 
-CELERY_ROUTES = "{}celery.Router".format(QUEUE_VARIANT)
+CELERY_ROUTES = "{}celery.route_task".format(QUEUE_VARIANT)
 
 # STATIC_URL_BASE specifies the base url to use for static files
 STATIC_URL_BASE = ENV_TOKENS.get('STATIC_URL_BASE', None)
@@ -567,3 +567,20 @@ if FEATURES.get('ENABLE_CORS_HEADERS'):
     CORS_ALLOW_HEADERS = corsheaders_default_headers + (
         'use-jwt-cookie',
     )
+
+######################## CELERY ROTUING ########################
+
+# Defines alternate environment tasks, as a dict of form { task_name: alternate_queue }
+ALTERNATE_ENV_TASKS = {
+    'completion_aggregator.tasks.update_aggregators': 'lms',
+    'openedx.core.djangoapps.content.block_structure.tasks.update_course_in_cache': 'lms',
+    'openedx.core.djangoapps.content.block_structure.tasks.update_course_in_cache_v2': 'lms',
+}
+
+# Defines the task -> alternate worker queue to be used when routing.
+EXPLICIT_QUEUES = {
+    'lms.djangoapps.grades.tasks.compute_all_grades_for_course': {
+        'queue': POLICY_CHANGE_GRADES_ROUTING_KEY},
+    'cms.djangoapps.contentstore.tasks.update_search_index': {
+        'queue': UPDATE_SEARCH_INDEX_JOB_QUEUE},
+}

common/djangoapps/entitlements/tasks.py

@@ -5,13 +5,11 @@ This file contains celery tasks for entitlements-related functionality.
 
 from celery import task
 from celery.utils.log import get_task_logger
-from django.conf import settings
 
 from common.djangoapps.entitlements.models import CourseEntitlement
 
 LOGGER = get_task_logger(__name__)
-# Under cms the following setting is not defined, leading to errors during tests.
-ROUTING_KEY = getattr(settings, 'ENTITLEMENTS_EXPIRATION_ROUTING_KEY', None)
+
 # Maximum number of retries before giving up on awarding credentials.
 # For reference, 11 retries with exponential backoff yields a maximum waiting
 # time of 2047 seconds (about 30 minutes). Setting this to None could yield
@@ -19,7 +17,7 @@ ROUTING_KEY = getattr(settings, 'ENTITLEMENTS_EXPIRATION_ROUTING_KEY', None)
 MAX_RETRIES = 11
 
 
-@task(bind=True, ignore_result=True, routing_key=ROUTING_KEY)
+@task(bind=True, ignore_result=True)
 def expire_old_entitlements(self, start, end, logid='...'):
     """
     This task is designed to be called to process a bundle of entitlements

lms/celery.py

@@ -5,12 +5,11 @@ and auto discover tasks in all installed django apps.
 Taken from: https://celery.readthedocs.org/en/latest/django/first-steps-with-django.html
 """
 
-
 import os
 
 from celery import Celery
 
-from openedx.core.lib.celery.routers import AlternateEnvironmentRouter
+from openedx.core.lib.celery.routers import route_task_queue
 
 # set the default Django settings module for the 'celery' program.
 os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'lms.envs.production')
@@ -24,14 +23,11 @@ APP.config_from_object('django.conf:settings')
 APP.autodiscover_tasks()
 
 
-class Router(AlternateEnvironmentRouter):
+def route_task(name, args, kwargs, options, task=None, **kw):  # pylint: disable=unused-argument
     """
-    An implementation of AlternateEnvironmentRouter, for routing tasks to non-cms queues.
+    Celery-defined method allowing for custom routing logic.
+
+    If None is returned from this method, default routing logic is used.
     """
 
-    @property
-    def alternate_env_tasks(self):
-        """
-        Defines alternate environment tasks, as a dict of form { task_name: alternate_queue }
-        """
-        return {}
+    return route_task_queue(name)

lms/djangoapps/bulk_email/tasks.py

@@ -196,8 +196,6 @@ def perform_delegate_email_batches(entry_id, course_id, task_input, action_name)
 
     total_recipients = combined_set.count()
 
-    routing_key = settings.BULK_EMAIL_ROUTING_KEY
-
     # Weird things happen if we allow empty querysets as input to emailing subtasks
     # The task appears to hang at "0 out of 0 completed" and never finishes.
     if total_recipients == 0:
@@ -217,7 +215,6 @@ def perform_delegate_email_batches(entry_id, course_id, task_input, action_name)
                 initial_subtask_status.to_dict(),
             ),
             task_id=subtask_id,
-            routing_key=routing_key,
         )
         return new_subtask
 

lms/djangoapps/discussion/tasks.py

@@ -35,7 +35,6 @@ log = logging.getLogger(__name__)
 
 
 DEFAULT_LANGUAGE = 'en'
-ROUTING_KEY = getattr(settings, 'ACE_ROUTING_KEY', None)
 
 
 @task(base=LoggedTask)
@@ -60,7 +59,7 @@ class ResponseNotification(BaseMessageType):
     pass
 
 
-@task(base=LoggedTask, routing_key=ROUTING_KEY)
+@task(base=LoggedTask)
 def send_ace_message(context):
     context['course_id'] = CourseKey.from_string(context['course_id'])
 

lms/djangoapps/email_marketing/tasks.py

@@ -18,10 +18,9 @@ from .models import EmailMarketingConfiguration
 
 log = logging.getLogger(__name__)
 SAILTHRU_LIST_CACHE_KEY = "email.marketing.cache"
-ACE_ROUTING_KEY = getattr(settings, 'ACE_ROUTING_KEY', None)
 
 
-@task(bind=True, routing_key=ACE_ROUTING_KEY)
+@task(bind=True)
 def get_email_cookies_via_sailthru(self, user_email, post_parms):
     """
     Adds/updates Sailthru cookie information for a new user.
@@ -61,7 +60,7 @@ def get_email_cookies_via_sailthru(self, user_email, post_parms):
     return None
 
 
-@task(bind=True, default_retry_delay=3600, max_retries=24, routing_key=ACE_ROUTING_KEY)
+@task(bind=True, default_retry_delay=3600, max_retries=24)
 def update_user(self, sailthru_vars, email, site=None, new_user=False, activation=False):
     """
     Adds/updates Sailthru profile information for a user.
@@ -143,7 +142,7 @@ def is_default_site(site):
     return not site or site.get('id') == settings.SITE_ID
 
 
-@task(bind=True, default_retry_delay=3600, max_retries=24, routing_key=ACE_ROUTING_KEY)
+@task(bind=True, default_retry_delay=3600, max_retries=24)
 def update_user_email(self, new_email, old_email):
     """
     Adds/updates Sailthru when a user email address is changed
@@ -303,7 +302,7 @@ def _retryable_sailthru_error(error):
     return code == 9 or code == 43
 
 
-@task(bind=True, routing_key=ACE_ROUTING_KEY)
+@task(bind=True)
 def update_course_enrollment(self, email, course_key, mode, site=None):
     """Adds/updates Sailthru when a user adds to cart/purchases/upgrades a course
          Args:

lms/djangoapps/grades/management/commands/compute_grades.py

@@ -80,7 +80,7 @@ class Command(BaseCommand):
         """
         Enqueue all tasks, in shuffled order.
         """
-        task_options = {'routing_key': options['routing_key']} if options.get('routing_key') else {}
+        task_options = {'queue': options['routing_key']} if options.get('routing_key') else {}
         for seq_id, kwargs in enumerate(self._shuffled_task_kwargs(options)):
             kwargs['seq_id'] = seq_id
             result = tasks.compute_grades_for_course_v2.apply_async(kwargs=kwargs, **task_options)

lms/djangoapps/grades/management/commands/tests/test_compute_grades.py

@@ -92,19 +92,19 @@ class TestComputeGrades(SharedModuleStoreTestCase):
         # Order doesn't matter, but can't use a set because dicts aren't hashable
         expected = [
             ({
-                'routing_key': 'key',
+                'queue': 'key',
                 'kwargs': _kwargs(self.course_keys[0], 0)
             },),
             ({
-                'routing_key': 'key',
+                'queue': 'key',
                 'kwargs': _kwargs(self.course_keys[0], 2)
             },),
             ({
-                'routing_key': 'key',
+                'queue': 'key',
                 'kwargs': _kwargs(self.course_keys[3], 0)
             },),
             ({
-                'routing_key': 'key',
+                'queue': 'key',
                 'kwargs': _kwargs(self.course_keys[3], 2)
             },),
         ]

lms/djangoapps/grades/tasks.py

@@ -48,7 +48,7 @@ RETRY_DELAY_SECONDS = 40
 SUBSECTION_GRADE_TIMEOUT_SECONDS = 300
 
 
-@task(base=LoggedPersistOnFailureTask, routing_key=settings.POLICY_CHANGE_GRADES_ROUTING_KEY)
+@task(base=LoggedPersistOnFailureTask)
 def compute_all_grades_for_course(**kwargs):
     """
     Compute grades for all students in the specified course.
@@ -69,7 +69,7 @@ def compute_all_grades_for_course(**kwargs):
                 'batch_size': batch_size,
             })
             compute_grades_for_course_v2.apply_async(
-                kwargs=kwargs, routing_key=settings.POLICY_CHANGE_GRADES_ROUTING_KEY
+                kwargs=kwargs, queue=settings.POLICY_CHANGE_GRADES_ROUTING_KEY
             )
 
 
@@ -131,7 +131,6 @@ def compute_grades_for_course(course_key, offset, batch_size, **kwargs):  # pyli
     time_limit=SUBSECTION_GRADE_TIMEOUT_SECONDS,
     max_retries=2,
     default_retry_delay=RETRY_DELAY_SECONDS,
-    routing_key=settings.POLICY_CHANGE_GRADES_ROUTING_KEY
 )
 def recalculate_course_and_subsection_grades_for_user(self, **kwargs):  # pylint: disable=unused-argument
     """
@@ -171,8 +170,7 @@ def recalculate_course_and_subsection_grades_for_user(self, **kwargs):  # pylint
     base=LoggedPersistOnFailureTask,
     time_limit=SUBSECTION_GRADE_TIMEOUT_SECONDS,
     max_retries=2,
-    default_retry_delay=RETRY_DELAY_SECONDS,
-    routing_key=settings.RECALCULATE_GRADES_ROUTING_KEY
+    default_retry_delay=RETRY_DELAY_SECONDS
 )
 def recalculate_subsection_grade_v3(self, **kwargs):
     """

lms/djangoapps/instructor_task/tasks.py

@@ -162,7 +162,6 @@ def send_bulk_course_email(entry_id, _xmodule_instance_args):
 @task(
     name='lms.djangoapps.instructor_task.tasks.calculate_problem_responses_csv.v2',
     base=BaseInstructorTask,
-    routing_key=settings.GRADES_DOWNLOAD_ROUTING_KEY,
 )
 def calculate_problem_responses_csv(entry_id, xmodule_instance_args):
     """
@@ -175,7 +174,7 @@ def calculate_problem_responses_csv(entry_id, xmodule_instance_args):
     return run_main_task(entry_id, task_fn, action_name)
 
 
-@task(base=BaseInstructorTask, routing_key=settings.GRADES_DOWNLOAD_ROUTING_KEY)
+@task(base=BaseInstructorTask)
 def calculate_grades_csv(entry_id, xmodule_instance_args):
     """
     Grade a course and push the results to an S3 bucket for download.
@@ -191,7 +190,7 @@ def calculate_grades_csv(entry_id, xmodule_instance_args):
     return run_main_task(entry_id, task_fn, action_name)
 
 
-@task(base=BaseInstructorTask, routing_key=settings.GRADES_DOWNLOAD_ROUTING_KEY)
+@task(base=BaseInstructorTask)
 def calculate_problem_grade_report(entry_id, xmodule_instance_args):
     """
     Generate a CSV for a course containing all students' problem
@@ -256,7 +255,7 @@ def calculate_may_enroll_csv(entry_id, xmodule_instance_args):
     return run_main_task(entry_id, task_fn, action_name)
 
 
-@task(base=BaseInstructorTask, routing_key=settings.GRADES_DOWNLOAD_ROUTING_KEY)
+@task(base=BaseInstructorTask)
 def generate_certificates(entry_id, xmodule_instance_args):
     """
     Grade students and generate certificates.

lms/djangoapps/verify_student/tasks.py

@@ -15,8 +15,6 @@ from django.core.mail import EmailMessage
 from common.djangoapps.edxmako.shortcuts import render_to_string
 from openedx.core.djangoapps.site_configuration import helpers as configuration_helpers
 
-ACE_ROUTING_KEY = getattr(settings, 'ACE_ROUTING_KEY', None)
-SOFTWARE_SECURE_VERIFICATION_ROUTING_KEY = getattr(settings, 'SOFTWARE_SECURE_VERIFICATION_ROUTING_KEY', None)
 log = logging.getLogger(__name__)
 
 
@@ -73,7 +71,7 @@ class BaseSoftwareSecureTask(Task):
             )
 
 
-@task(routing_key=ACE_ROUTING_KEY)
+@task
 def send_verification_status_email(context):
     """
     Spins a task to send verification status email to the learner
@@ -99,7 +97,6 @@ def send_verification_status_email(context):
     bind=True,
     default_retry_delay=settings.SOFTWARE_SECURE_REQUEST_RETRY_DELAY,
     max_retries=settings.SOFTWARE_SECURE_RETRY_MAX_ATTEMPTS,
-    routing_key=SOFTWARE_SECURE_VERIFICATION_ROUTING_KEY,
 )
 def send_request_to_ss_for_user(self, user_verification_id, copy_id_photo_from):
     """

lms/envs/production.py

@@ -150,7 +150,7 @@ CELERY_QUEUES = {
     HIGH_MEM_QUEUE: {},
 }
 
-CELERY_ROUTES = "{}celery.Router".format(QUEUE_VARIANT)
+CELERY_ROUTES = "{}celery.route_task".format(QUEUE_VARIANT)
 CELERYBEAT_SCHEDULE = {}  # For scheduling tasks, entries can be added to this dict
 
 # STATIC_ROOT specifies the directory where static files are
@@ -974,3 +974,62 @@ COMPLETION_VIDEO_COMPLETE_PERCENTAGE = ENV_TOKENS.get('COMPLETION_VIDEO_COMPLETE
                                                       COMPLETION_VIDEO_COMPLETE_PERCENTAGE)
 COMPLETION_VIDEO_COMPLETE_PERCENTAGE = ENV_TOKENS.get('COMPLETION_BY_VIEWING_DELAY_MS',
                                                       COMPLETION_BY_VIEWING_DELAY_MS)
+
+######################## CELERY ROUTING ########################
+
+# Defines alternate environment tasks, as a dict of form { task_name: alternate_queue }
+ALTERNATE_ENV_TASKS = {}
+
+# Defines the task -> alternate worker queue to be used when routing.
+EXPLICIT_QUEUES = {
+    'openedx.core.djangoapps.content.course_overviews.tasks.async_course_overview_update': {
+        'queue': GRADES_DOWNLOAD_ROUTING_KEY},
+    'lms.djangoapps.bulk_email.tasks.send_course_email': {
+        'queue': BULK_EMAIL_ROUTING_KEY},
+    'openedx.core.djangoapps.heartbeat.tasks.sample_task': {
+        'queue': HEARTBEAT_CELERY_ROUTING_KEY},
+    'lms.djangoapps.instructor_task.tasks.calculate_grades_csv': {
+        'queue': GRADES_DOWNLOAD_ROUTING_KEY},
+    'lms.djangoapps.instructor_task.tasks.calculate_problem_grade_report': {
+        'queue': GRADES_DOWNLOAD_ROUTING_KEY},
+    'lms.djangoapps.instructor_task.tasks.generate_certificates': {
+        'queue': GRADES_DOWNLOAD_ROUTING_KEY},
+    'lms.djangoapps.email_marketing.tasks.get_email_cookies_via_sailthru': {
+        'queue': ACE_ROUTING_KEY},
+    'lms.djangoapps.email_marketing.tasks.update_user': {
+        'queue': ACE_ROUTING_KEY},
+    'lms.djangoapps.email_marketing.tasks.update_user_email': {
+        'queue': ACE_ROUTING_KEY},
+    'lms.djangoapps.email_marketing.tasks.update_course_enrollment': {
+        'queue': ACE_ROUTING_KEY},
+    'lms.djangoapps.verify_student.tasks.send_verification_status_email': {
+        'queue': ACE_ROUTING_KEY},
+    'lms.djangoapps.verify_student.tasks.send_ace_message': {
+        'queue': ACE_ROUTING_KEY},
+    'lms.djangoapps.verify_student.tasks.send_request_to_ss_for_user': {
+        'queue': SOFTWARE_SECURE_VERIFICATION_ROUTING_KEY},
+    'openedx.core.djangoapps.schedules.tasks._recurring_nudge_schedule_send': {
+        'queue': ACE_ROUTING_KEY},
+    'openedx.core.djangoapps.schedules.tasks._upgrade_reminder_schedule_send': {
+        'queue': ACE_ROUTING_KEY},
+    'openedx.core.djangoapps.schedules.tasks._course_update_schedule_send': {
+        'queue': ACE_ROUTING_KEY},
+    'openedx.core.djangoapps.schedules.tasks.v1.tasks.send_grade_to_credentials': {
+        'queue': CREDENTIALS_GENERATION_ROUTING_KEY},
+    'common.djangoapps.entitlements.tasks.expire_old_entitlements': {
+        'queue': ENTITLEMENTS_EXPIRATION_ROUTING_KEY},
+    'lms.djangoapps.grades.tasks.recalculate_course_and_subsection_grades_for_user': {
+        'queue': POLICY_CHANGE_GRADES_ROUTING_KEY},
+    'lms.djangoapps.grades.tasks.recalculate_subsection_grade_v3': {
+        'queue': RECALCULATE_GRADES_ROUTING_KEY},
+    'openedx.core.djangoapps.programs.tasks.v1.tasks.award_program_certificates': {
+        'queue': PROGRAM_CERTIFICATES_ROUTING_KEY},
+    'openedx.core.djangoapps.programs.tasks.v1.tasks.revoke_program_certificates': {
+        'queue': PROGRAM_CERTIFICATES_ROUTING_KEY},
+    'openedx.core.djangoapps.programs.tasks.v1.tasks.update_certificate_visible_date_on_course_update': {
+        'queue': PROGRAM_CERTIFICATES_ROUTING_KEY},
+    'openedx.core.djangoapps.programs.tasks.v1.tasks.award_course_certificate': {
+        'queue': PROGRAM_CERTIFICATES_ROUTING_KEY},
+    'openedx.core.djangoapps.coursegraph.dump_course_to_neo4j': {
+        'queue': COURSEGRAPH_JOB_QUEUE},
+}

openedx/core/djangoapps/coursegraph/tasks.py

@@ -246,7 +246,7 @@ def should_dump_course(course_key, graph):
     return last_this_command_was_run < course_last_published_date
 
 
-@task(routing_key=settings.COURSEGRAPH_JOB_QUEUE)
+@task
 def dump_course_to_neo4j(course_key_string, credentials):
     """
     Serializes a course and writes it to neo4j.

openedx/core/djangoapps/credentials/tasks/v1/tasks.py

@@ -13,11 +13,6 @@ from openedx.core.djangoapps.credentials.utils import get_credentials_api_client
 
 logger = get_task_logger(__name__)
 
-# Under cms the following setting is not defined, leading to errors during tests.
-# These tasks aren't strictly credentials generation, but are similar in the sense
-# that they generate records on the credentials side. And have a similar SLA.
-ROUTING_KEY = getattr(settings, 'CREDENTIALS_GENERATION_ROUTING_KEY', None)
-
 # Maximum number of retries before giving up.
 # For reference, 11 retries with exponential backoff yields a maximum waiting
 # time of 2047 seconds (about 30 minutes). Setting this to None could yield
@@ -25,7 +20,7 @@ ROUTING_KEY = getattr(settings, 'CREDENTIALS_GENERATION_ROUTING_KEY', None)
 MAX_RETRIES = 11
 
 
-@task(bind=True, ignore_result=True, routing_key=ROUTING_KEY)
+@task(bind=True, ignore_result=True)
 def send_grade_to_credentials(self, username, course_run_key, verified, letter_grade, percent_grade):
     """ Celery task to notify the Credentials IDA of a grade change via POST. """
     logger.info(u'Running task send_grade_to_credentials for username %s and course %s', username, course_run_key)

openedx/core/djangoapps/heartbeat/tasks.py

@@ -4,9 +4,8 @@ A trivial task for health checks
 
 
 from celery.task import task
-from django.conf import settings
 
 
-@task(routing_key=settings.HEARTBEAT_CELERY_ROUTING_KEY)
+@task
 def sample_task():
     return True

openedx/core/djangoapps/programs/tasks.py

@@ -22,9 +22,6 @@ from openedx.core.djangoapps.programs.utils import ProgramProgressMeter
 from openedx.core.djangoapps.site_configuration import helpers as configuration_helpers
 
 LOGGER = get_task_logger(__name__)
-# Under cms the following setting is not defined, leading to errors during tests.
-ROUTING_KEY = getattr(settings, 'CREDENTIALS_GENERATION_ROUTING_KEY', None)
-PROGRAM_CERTIFICATES_ROUTING_KEY = getattr(settings, 'PROGRAM_CERTIFICATES_ROUTING_KEY', None)
 # Maximum number of retries before giving up on awarding credentials.
 # For reference, 11 retries with exponential backoff yields a maximum waiting
 # time of 2047 seconds (about 30 minutes). Setting this to None could yield
@@ -123,7 +120,7 @@ def award_program_certificate(client, username, program_uuid, visible_date):
     })
 
 
-@task(bind=True, ignore_result=True, routing_key=PROGRAM_CERTIFICATES_ROUTING_KEY)
+@task(bind=True, ignore_result=True)
 def award_program_certificates(self, username):
     """
     This task is designed to be called whenever a student's completion status
@@ -285,7 +282,7 @@ def post_course_certificate(client, username, certificate, visible_date):
     })
 
 
-@task(bind=True, ignore_result=True, routing_key=ROUTING_KEY)
+@task(bind=True, ignore_result=True)
 def award_course_certificate(self, username, course_run_key):
     """
     This task is designed to be called whenever a student GeneratedCertificate is updated.
@@ -399,7 +396,7 @@ def revoke_program_certificate(client, username, program_uuid):
     })
 
 
-@task(bind=True, ignore_result=True, routing_key=PROGRAM_CERTIFICATES_ROUTING_KEY)
+@task(bind=True, ignore_result=True)
 def revoke_program_certificates(self, username, course_key):
     """
     This task is designed to be called whenever a student's course certificate is
@@ -522,7 +519,7 @@ def revoke_program_certificates(self, username, course_key):
     LOGGER.info(u'Successfully completed the task revoke_program_certificates for username %s', username)
 
 
-@task(bind=True, ignore_result=True, routing_key=PROGRAM_CERTIFICATES_ROUTING_KEY)
+@task(bind=True, ignore_result=True)
 def update_certificate_visible_date_on_course_update(self, course_key):
     """
     This task is designed to be called whenever a course is updated with

openedx/core/djangoapps/schedules/tasks.py

@@ -143,7 +143,7 @@ class BinnedScheduleMessageBaseTask(ScheduleMessageBaseTask):
         raise NotImplementedError
 
 
-@task(base=LoggedTask, ignore_result=True, routing_key=ROUTING_KEY)
+@task(base=LoggedTask, ignore_result=True)
 def _recurring_nudge_schedule_send(site_id, msg_str):
     _schedule_send(
         msg_str,
@@ -153,7 +153,7 @@ def _recurring_nudge_schedule_send(site_id, msg_str):
     )
 
 
-@task(base=LoggedTask, ignore_result=True, routing_key=ROUTING_KEY)
+@task(base=LoggedTask, ignore_result=True)
 def _upgrade_reminder_schedule_send(site_id, msg_str):
     _schedule_send(
         msg_str,
@@ -163,7 +163,7 @@ def _upgrade_reminder_schedule_send(site_id, msg_str):
     )
 
 
-@task(base=LoggedTask, ignore_result=True, routing_key=ROUTING_KEY)
+@task(base=LoggedTask, ignore_result=True)
 def _course_update_schedule_send(site_id, msg_str):
     _schedule_send(
         msg_str,

openedx/core/lib/celery/routers.py

@@ -5,62 +5,41 @@ For more, see https://celery.readthedocs.io/en/latest/userguide/routing.html#rou
 """
 
 import logging
-from abc import ABCMeta, abstractproperty
 
-from django.conf import settings
-import six
 
 log = logging.getLogger(__name__)
 
 
-class AlternateEnvironmentRouter(six.with_metaclass(ABCMeta, object)):
+def route_task_queue(name):
     """
-    A custom Router class for use in routing celery tasks to non-default queues.
-    """
-
-    @abstractproperty
-    def alternate_env_tasks(self):
-        """
-        Defines the task -> alternate worker environment to be used when routing.
-
-        Subclasses must override this property with their own specific mappings.
-        """
-        return {}
-
-    @property
-    def explicit_queues(self):
-        """
-        Defines the task -> alternate worker queue to be used when routing.
-        """
-        return {}
+    Helper method allowing for custom routing logic.
 
-    def route_for_task(self, task, args=None, kwargs=None):  # pylint: disable=unused-argument
-        """
-        Celery-defined method allowing for custom routing logic.
+    If None is returned from this method, default routing logic is used.
+    """
+    from django.conf import settings  # pylint: disable=import-outside-toplevel
 
-        If None is returned from this method, default routing logic is used.
-        """
-        if task in self.explicit_queues:
-            return self.explicit_queues[task]
+    if name in settings.EXPLICIT_QUEUES:
+        return settings.EXPLICIT_QUEUES[name]
 
-        alternate_env = self.alternate_env_tasks.get(task, None)
-        if alternate_env:
-            return self.ensure_queue_env(alternate_env)
+    alternate_env = settings.ALTERNATE_ENV_TASKS.get(name, None)
+    if alternate_env:
+        return ensure_queue_env(alternate_env)
 
-        return None
 
-    def ensure_queue_env(self, desired_env):
-        """
-        Helper method to get the desired type of queue.
+def ensure_queue_env(desired_env):
+    """
+    Helper method to get the desired type of queue.
 
-        If no such queue is defined, default routing logic is used.
-        """
-        queues = getattr(settings, 'CELERY_QUEUES', None)
-        return next(
-            (
-                queue
-                for queue in queues
-                if '.{}.'.format(desired_env) in queue
-            ),
-            None
-        )
+    If no such queue is defined, default routing logic is used.
+    """
+    from django.conf import settings  # pylint: disable=import-outside-toplevel
+
+    queues = getattr(settings, 'CELERY_QUEUES', None)
+    return next(
+        (
+            queue
+            for queue in queues
+            if '.{}.'.format(desired_env) in queue
+        ),
+        None
+    )