Merge pull request #466 from timomeara/master

Add attempt_count to limit the number of times a filed task will be re-attempted

django_q/cluster.py

@@ -478,7 +478,12 @@ def save_task(task, broker: Broker):
                 existing_task.stopped = task["stopped"]
                 existing_task.result = task["result"]
                 existing_task.success = task["success"]
+                existing_task.attempt_count = existing_task.attempt_count + 1
                 existing_task.save()
+
+            if Conf.MAX_ATTEMPTS > 0 and existing_task.attempt_count >= Conf.MAX_ATTEMPTS:
+                broker.acknowledge(task['ack_id'])
+
         else:
             Task.objects.create(
                 id=task["id"],
@@ -492,6 +497,7 @@ def save_task(task, broker: Broker):
                 result=task["result"],
                 group=task.get("group"),
                 success=task["success"],
+                attempt_count=1
             )
     except Exception as e:
         logger.error(e)

django_q/conf.py

@@ -164,6 +164,9 @@ class Conf:
     # Optional error reporting setup
     ERROR_REPORTER = conf.get("error_reporter", {})
 
+    # Optional attempt count. set to 0 for infinite attempts
+    MAX_ATTEMPTS = conf.get('max_attempts', 0)
+
     # OSX doesn't implement qsize because of missing sem_getvalue()
     try:
         QSIZE = Queue().qsize() == 0

django_q/migrations/0013_task_attempt_count.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.0.7 on 2020-08-11 15:17
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('django_q', '0012_auto_20200702_1608'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='task',
+            name='attempt_count',
+            field=models.IntegerField(default=0),
+        ),
+    ]

django_q/models.py

@@ -29,6 +29,7 @@ class Task(models.Model):
     started = models.DateTimeField(editable=False)
     stopped = models.DateTimeField(editable=False)
     success = models.BooleanField(default=True, editable=False)
+    attempt_count = models.IntegerField(default=0)
 
     @staticmethod
     def get_result(task_id):

django_q/tests/test_cluster.py

@@ -397,6 +397,41 @@ def test_bad_secret(broker, monkeypatch):
     broker.delete_queue()
 
 
+@pytest.mark.django_db
+def test_attempt_count(broker, monkeypatch):
+    monkeypatch.setattr(Conf, 'MAX_ATTEMPTS', 3)
+    tag = uuid()
+    task = {'id': tag[1],
+            'name': tag[0],
+            'func': 'math.copysign',
+            'args': (1, -1),
+            'kwargs': {},
+            'started': timezone.now(),
+            'stopped': timezone.now(),
+            'success': False,
+            'result': None}
+    # initial save - no success
+    save_task(task, broker)
+    assert Task.objects.filter(id=task['id']).exists()
+    saved_task = Task.objects.get(id=task['id'])
+    assert saved_task.attempt_count == 1
+    sleep(0.5)
+    # second save
+    old_stopped = task['stopped']
+    task['stopped'] = timezone.now()
+    save_task(task, broker)
+    saved_task = Task.objects.get(id=task['id'])
+    assert saved_task.attempt_count == 2
+    # third save -
+    task['stopped'] = timezone.now()
+    save_task(task, broker)
+    saved_task = Task.objects.get(id=task['id'])
+    assert saved_task.attempt_count == 3
+    # task should be removed from queue
+    assert broker.queue_size() == 0
+
+
+
 @pytest.mark.django_db
 def test_update_failed(broker):
     tag = uuid()

docs/admin.rst

@@ -33,6 +33,29 @@ You can resubmit a failed task back to the queue using the admins action menu.
 
 Uses the :class:`Failure` proxy model
 
+
+
+Customize the admin UI by creating your own ``admin.ModelAdmin`` class and use ``admin.site.unregister`` and ``admin.site.register`` to replace the default
+for example:
+
+.. code-block:: python
+    from django_q import models as q_models
+    from django_q import admin as q_admin
+
+    admin.site.unregister([q_models.Failure])
+    @admin.register(q_models.Failure)
+    class ChildClassAdmin(q_admin.FailAdmin):
+        list_display = (
+            'name',
+            'func',
+            'result',
+            'started',
+            # add attempt_count to list_display
+            'attempt_count'
+        )
+
+
+
 Scheduled tasks
 ---------------
 

docs/configure.rst

@@ -75,6 +75,15 @@ ack_failures
 
 When set to ``True``, also acknowledge unsuccessful tasks. This causes failed tasks to be considered as successful deliveries, thereby removing them from the task queue. Can also be set per-task by passing the ``ack_failure`` option to :func:`async_task`. Defaults to ``False``.
 
+
+.. _max_attempts:
+
+max_attempts
+~~~~~~~~~~~~~
+
+Limit the number of retry attempts for failed tasks. Set to 0 for infinite retries. Defaults to 0
+
+
 .. _retry:
 
 retry