Resolve Celery TaskObject Race Condition

contentcuration/contentcuration/migrations/0145_custom_task_metadata.py

@@ -0,0 +1,48 @@
+# Generated by Django 3.2.19 on 2023-09-14 05:08
+import django.core.validators
+import django.db.models.deletion
+from celery import states
+from django.conf import settings
+from django.db import migrations
+from django.db import models
+
+def transfer_data(apps, schema_editor):
+    CustomTaskMetadata = apps.get_model('contentcuration', 'CustomTaskMetadata')
+    TaskResult = apps.get_model('django_celery_results', 'taskresult')
+
+    old_task_results = TaskResult.objects.filter(status__in=states.UNREADY_STATES)
+
+    for old_task_result in old_task_results:
+        CustomTaskMetadata.objects.create(
+            task_id=old_task_result.task_id,
+            user=old_task_result.user,
+            channel_id=old_task_result.channel_id,
+            progress=old_task_result.progress,
+            signature=old_task_result.signature,
+        )
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contentcuration', '0144_soft_delete_user'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='CustomTaskMetadata',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('task_id', models.CharField(max_length=255, unique=True)),
+                ('channel_id', models.UUIDField(blank=True, db_index=True, null=True)),
+                ('progress', models.IntegerField(blank=True, null=True, validators=[django.core.validators.MinValueValidator(0), django.core.validators.MaxValueValidator(100)])),
+                ('signature', models.CharField(max_length=32, null=True)),
+                ('date_created', models.DateTimeField(auto_now_add=True, help_text='Datetime field when the custom_metadata for task was created in UTC', verbose_name='Created DateTime')),
+                ('user', models.ForeignKey(null=True, on_delete=django.db.models.deletion.CASCADE, related_name='tasks', to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+        migrations.AddIndex(
+            model_name='customtaskmetadata',
+            index=models.Index(fields=['signature'], name='task_result_signature'),
+        ),
+        migrations.RunPython(transfer_data),
+    ]

contentcuration/contentcuration/migrations/0146_drop_taskresult_fields.py

@@ -0,0 +1,37 @@
+# Generated by Django 3.2.19 on 2023-09-14 10:42
+from django.db import migrations
+
+class Migration(migrations.Migration):
+
+    replaces = [('django_celery_results', '0145_custom_task_metadata'),]
+
+    def __init__(self, name, app_label):
+        super(Migration, self).__init__(name, 'django_celery_results')
+
+    dependencies = [
+        ('contentcuration', '0145_custom_task_metadata'),
+        ('contentcuration', '0141_add_task_signature'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='taskresult',
+            name='channel_id',
+        ),
+        migrations.RemoveField(
+            model_name='taskresult',
+            name='progress',
+        ),
+        migrations.RemoveField(
+            model_name='taskresult',
+            name='user',
+        ),
+        migrations.RemoveField(
+            model_name='taskresult',
+            name='signature',
+        ),
+        migrations.RemoveIndex(
+            model_name='taskresult',
+            name='task_result_signature_idx',
+        ),
+    ]

contentcuration/contentcuration/models.py

@@ -7,7 +7,6 @@
 from datetime import datetime
 
 import pytz
-from celery import states as celery_states
 from django.conf import settings
 from django.contrib.auth.base_user import AbstractBaseUser
 from django.contrib.auth.base_user import BaseUserManager
@@ -46,7 +45,6 @@
 from django.dispatch import receiver
 from django.utils import timezone
 from django.utils.translation import gettext as _
-from django_celery_results.models import TaskResult
 from django_cte import With
 from le_utils import proquint
 from le_utils.constants import content_kinds
@@ -2566,58 +2564,29 @@ def serialize_to_change_dict(self):
         return self.serialize(self)
 
 
-class TaskResultCustom(object):
-    """
-    Custom fields to add to django_celery_results's TaskResult model
-
-    If adding fields to this class, run `makemigrations` then move the generated migration from the
-    `django_celery_results` app to the `contentcuration` app and override the constructor to change
-    the app_label. See `0141_add_task_signature` for an example
-    """
+class CustomTaskMetadata(models.Model):
+    # Task_id for reference
+    task_id = models.CharField(
+        max_length=255,  # Adjust the max_length as needed
+        unique=True,
+    )
     # user shouldn't be null, but in order to append the field, this needs to be allowed
     user = models.ForeignKey(settings.AUTH_USER_MODEL, related_name="tasks", on_delete=models.CASCADE, null=True)
     channel_id = DjangoUUIDField(db_index=True, null=True, blank=True)
     progress = models.IntegerField(null=True, blank=True, validators=[MinValueValidator(0), MaxValueValidator(100)])
     # a hash of the task name and kwargs for identifying repeat tasks
     signature = models.CharField(null=True, blank=False, max_length=32)
-
-    super_as_dict = TaskResult.as_dict
-
-    def as_dict(self):
-        """
-        :return: A dictionary representation
-        """
-        super_dict = self.super_as_dict()
-        super_dict.update(
-            user_id=self.user_id,
-            channel_id=self.channel_id,
-            progress=self.progress,
-        )
-        return super_dict
-
-    @classmethod
-    def contribute_to_class(cls, model_class=TaskResult):
-        """
-        Adds fields to model, by default TaskResult
-        :param model_class: TaskResult model
-        """
-        for field in dir(cls):
-            if not field.startswith("_") and field not in ('contribute_to_class', 'Meta'):
-                model_class.add_to_class(field, getattr(cls, field))
-
-        # manually add Meta afterwards
-        setattr(model_class._meta, 'indexes', getattr(model_class._meta, 'indexes', []) + cls.Meta.indexes)
+    date_created = models.DateTimeField(
+        auto_now_add=True,
+        verbose_name=_('Created DateTime'),
+        help_text=_('Datetime field when the custom_metadata for task was created in UTC')
+    )
 
     class Meta:
         indexes = [
             # add index that matches query usage for signature
             models.Index(
                 fields=['signature'],
-                name='task_result_signature_idx',
-                condition=Q(status__in=celery_states.UNREADY_STATES),
+                name='task_result_signature',
             ),
         ]
-
-
-# trigger class contributions immediately
-TaskResultCustom.contribute_to_class()

contentcuration/contentcuration/tests/helpers.py

@@ -3,10 +3,10 @@
 
 import mock
 from celery import states
+from django_celery_results.models import TaskResult
 from search.models import ContentNodeFullTextSearch
 
 from contentcuration.models import ContentNode
-from contentcuration.models import TaskResult
 
 
 def clear_tasks(except_task_id=None):

contentcuration/contentcuration/tests/test_asynctask.py

@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 
 import threading
+import time
 import uuid
 
 import pytest
@@ -9,12 +10,11 @@
 from celery.utils.log import get_task_logger
 from django.core.management import call_command
 from django.test import TransactionTestCase
+from django_celery_results.models import TaskResult
 
 from . import testdata
 from .helpers import clear_tasks
 from contentcuration.celery import app
-from contentcuration.models import TaskResult
-
 
 logger = get_task_logger(__name__)
 
@@ -36,6 +36,22 @@ def test_task(self, **kwargs):
     return 42
 
 
+# Create a Task that takes a bit longer to be executed
+@app.task(bind=True, name="test_task_delayed")
+def test_task_delayed(self, delay_seconds=100, **kwargs):
+    """
+    This is a mock task that takes a bit longer to execute
+    so that revoke function can be called succesfully without test being SUCCESS before hand,
+    to be used ONLY for unit-testing various pieces of the
+    async task API.
+    :return: The number 42
+    """
+    time.sleep(delay_seconds)
+    logger.info("Request ID = {}".format(self.request.id))
+    assert TaskResult.objects.filter(task_id=self.request.id).count() == 1
+    return 42
+
+
 @app.task(name="error_test_task")
 def error_test_task(**kwargs):
     """
@@ -88,11 +104,8 @@ def _celery_task_worker():
     ])
 
 
-def _celery_progress_monitor(thread_event):
-    def _on_iteration(receiver):
-        if thread_event.is_set():
-            receiver.should_stop = True
-    app.events.monitor_progress(on_iteration=_on_iteration)
+def _return_celery_task_object(task_id):
+    return TaskResult.objects.get(task_id=task_id)
 
 
 class AsyncTaskTestCase(TransactionTestCase):
@@ -108,11 +121,6 @@ class AsyncTaskTestCase(TransactionTestCase):
     @classmethod
     def setUpClass(cls):
         super(AsyncTaskTestCase, cls).setUpClass()
-        # start progress monitor in separate thread
-        cls.monitor_thread_event = threading.Event()
-        cls.monitor_thread = threading.Thread(target=_celery_progress_monitor, args=(cls.monitor_thread_event,))
-        cls.monitor_thread.start()
-
         # start celery worker in separate thread
         cls.worker_thread = threading.Thread(target=_celery_task_worker)
         cls.worker_thread.start()
@@ -122,8 +130,6 @@ def tearDownClass(cls):
         super(AsyncTaskTestCase, cls).tearDownClass()
         # tell the work thread to stop through the celery control API
         if cls.worker_thread:
-            cls.monitor_thread_event.set()
-            cls.monitor_thread.join(5)
             app.control.shutdown()
             cls.worker_thread.join(5)
 
@@ -152,15 +158,14 @@ def test_asynctask_reports_success(self):
         contains the return value of the task.
         """
         async_result = test_task.enqueue(self.user)
-
         result = self._wait_for(async_result)
         task_result = async_result.get_model()
+        celery_task_result = TaskResult.objects.get(task_id=task_result.task_id)
         self.assertEqual(task_result.user, self.user)
-
         self.assertEqual(result, 42)
         task_result.refresh_from_db()
         self.assertEqual(async_result.result, 42)
-        self.assertEqual(task_result.task_name, "test_task")
+        self.assertEqual(celery_task_result.task_name, "test_task")
         self.assertEqual(async_result.status, states.SUCCESS)
         self.assertEqual(TaskResult.objects.get(task_id=async_result.id).result, "42")
         self.assertEqual(TaskResult.objects.get(task_id=async_result.id).status, states.SUCCESS)
@@ -177,11 +182,12 @@ def test_asynctask_reports_error(self):
             self._wait_for(async_result)
 
         task_result = async_result.get_model()
-        self.assertEqual(task_result.status, states.FAILURE)
-        self.assertIsNotNone(task_result.traceback)
+        celery_task_result = _return_celery_task_object(task_result.task_id)
+        self.assertEqual(celery_task_result.status, states.FAILURE)
+        self.assertIsNotNone(celery_task_result.traceback)
 
         self.assertIn(
-            "I'm sorry Dave, I'm afraid I can't do that.", task_result.result
+            "I'm sorry Dave, I'm afraid I can't do that.", celery_task_result.result
         )
 
     def test_only_create_async_task_creates_task_entry(self):
@@ -194,17 +200,6 @@ def test_only_create_async_task_creates_task_entry(self):
         self.assertEquals(result, 42)
         self.assertEquals(TaskResult.objects.filter(task_id=async_result.task_id).count(), 0)
 
-    def test_enqueue_task_adds_result_with_necessary_info(self):
-        async_result = test_task.enqueue(self.user, is_test=True)
-        try:
-            task_result = TaskResult.objects.get(task_id=async_result.task_id)
-        except TaskResult.DoesNotExist:
-            self.fail('Missing task result')
-
-        self.assertEqual(task_result.task_name, test_task.name)
-        _, _, encoded_kwargs = test_task.backend.encode_content(dict(is_test=True))
-        self.assertEqual(task_result.task_kwargs, encoded_kwargs)
-
     @pytest.mark.skip(reason="This test is flaky on Github Actions")
     def test_fetch_or_enqueue_task(self):
         expected_task = test_task.enqueue(self.user, is_test=True)
@@ -258,8 +253,11 @@ def test_requeue_task(self):
 
     def test_revoke_task(self):
         channel_id = uuid.uuid4()
-        async_result = test_task.enqueue(self.user, channel_id=channel_id)
-        test_task.revoke(channel_id=channel_id)
+        async_result = test_task_delayed.enqueue(self.user, channel_id=channel_id)
+        # A bit delay to let the task object be saved async,
+        # This delay is relatively small and hopefully wont cause any issues in the real time
+        time.sleep(0.5)
+        test_task_delayed.revoke(channel_id=channel_id)
 
         # this should raise an exception, even though revoked, because the task is in ready state but not success
         with self.assertRaises(Exception):

contentcuration/contentcuration/tests/utils/test_garbage_collect.py

@@ -11,6 +11,7 @@
 from django.core.files.base import ContentFile
 from django.core.files.storage import default_storage
 from django.urls import reverse_lazy
+from django_celery_results.models import TaskResult
 from le_utils.constants import content_kinds
 from le_utils.constants import file_formats
 from le_utils.constants import format_presets
@@ -19,7 +20,6 @@
 from contentcuration.constants import user_history
 from contentcuration.models import ContentNode
 from contentcuration.models import File
-from contentcuration.models import TaskResult
 from contentcuration.models import UserHistory
 from contentcuration.tests.base import BaseAPITestCase
 from contentcuration.tests.base import StudioTestCase
@@ -384,10 +384,9 @@ def test_clean_up(self):
 class CleanupTaskTestCase(StudioTestCase):
 
     def setUp(self):
-        user = self.admin_user
-        self.pruned_task = TaskResult.objects.create(task_id=uuid.uuid4().hex, status=states.SUCCESS, task_name="pruned_task", user_id=user.id)
-        self.failed_task = TaskResult.objects.create(task_id=uuid.uuid4().hex, status=states.FAILURE, task_name="failed_task", user_id=user.id)
-        self.recent_task = TaskResult.objects.create(task_id=uuid.uuid4().hex, status=states.SUCCESS, task_name="recent_task", user_id=user.id)
+        self.pruned_task = TaskResult.objects.create(task_id=uuid.uuid4().hex, status=states.SUCCESS, task_name="pruned_task")
+        self.failed_task = TaskResult.objects.create(task_id=uuid.uuid4().hex, status=states.FAILURE, task_name="failed_task")
+        self.recent_task = TaskResult.objects.create(task_id=uuid.uuid4().hex, status=states.SUCCESS, task_name="recent_task")
 
         # `date_done` uses `auto_now`, so manually set it
         done = datetime.now() - timedelta(days=8)