remove support for multi-reader dispatch queue

* Under the new postgres backed notify/listen message queue, this never
actually worked. Without using the database to store state, we can not
provide a at-most-once delivery mechanism w/ multi-readers.
* With this change, work is done ONLY on the node that requested for the
work to be done. Under rabbitmq, the node that was first to get the
message off the queue would do the work; presumably the least busy node.

awx/main/tasks.py

@@ -151,7 +151,7 @@ def inform_cluster_of_shutdown():
         logger.exception('Encountered problem with normal shutdown signal.')
 
 
-@task()
+@task(queue=get_local_queuename)
 def apply_cluster_membership_policies():
     started_waiting = time.time()
     with advisory_lock('cluster_policy_lock', wait=True):
@@ -307,7 +307,7 @@ def profile_sql(threshold=1, minutes=1):
         logger.error('SQL QUERIES >={}s ENABLED FOR {} MINUTE(S)'.format(threshold, minutes))
 
 
-@task()
+@task(queue=get_local_queuename)
 def send_notifications(notification_list, job_id=None):
     if not isinstance(notification_list, list):
         raise TypeError("notification_list should be of type list")
@@ -336,7 +336,7 @@ def send_notifications(notification_list, job_id=None):
                 logger.exception('Error saving notification {} result.'.format(notification.id))
 
 
-@task()
+@task(queue=get_local_queuename)
 def gather_analytics():
     from awx.conf.models import Setting
     from rest_framework.fields import DateTimeField
@@ -492,7 +492,7 @@ def awx_isolated_heartbeat():
         isolated_manager.IsolatedManager(CallbackQueueDispatcher.dispatch).health_check(isolated_instance_qs)
 
 
-@task()
+@task(queue=get_local_queuename)
 def awx_periodic_scheduler():
     with advisory_lock('awx_periodic_scheduler_lock', wait=False) as acquired:
         if acquired is False:
@@ -549,7 +549,7 @@ def awx_periodic_scheduler():
         state.save()
 
 
-@task()
+@task(queue=get_local_queuename)
 def handle_work_success(task_actual):
     try:
         instance = UnifiedJob.get_instance_by_type(task_actual['type'], task_actual['id'])
@@ -562,7 +562,7 @@ def handle_work_success(task_actual):
     schedule_task_manager()
 
 
-@task()
+@task(queue=get_local_queuename)
 def handle_work_error(task_id, *args, **kwargs):
     subtasks = kwargs.get('subtasks', None)
     logger.debug('Executing error task id %s, subtasks: %s' % (task_id, str(subtasks)))
@@ -602,7 +602,7 @@ def handle_work_error(task_id, *args, **kwargs):
         pass
 
 
-@task()
+@task(queue=get_local_queuename)
 def update_inventory_computed_fields(inventory_id):
     '''
     Signal handler and wrapper around inventory.update_computed_fields to
@@ -644,7 +644,7 @@ def update_smart_memberships_for_inventory(smart_inventory):
     return False
 
 
-@task()
+@task(queue=get_local_queuename)
 def update_host_smart_inventory_memberships():
     smart_inventories = Inventory.objects.filter(kind='smart', host_filter__isnull=False, pending_deletion=False)
     changed_inventories = set([])
@@ -660,7 +660,7 @@ def update_host_smart_inventory_memberships():
         smart_inventory.update_computed_fields()
 
 
-@task()
+@task(queue=get_local_queuename)
 def delete_inventory(inventory_id, user_id, retries=5):
     # Delete inventory as user
     if user_id is None:
@@ -1478,7 +1478,7 @@ class BaseTask(object):
 
 
 
-@task()
+@task(queue=get_local_queuename)
 class RunJob(BaseTask):
     '''
     Run a job using ansible-playbook.
@@ -1911,7 +1911,7 @@ class RunJob(BaseTask):
                 update_inventory_computed_fields.delay(inventory.id)
 
 
-@task()
+@task(queue=get_local_queuename)
 class RunProjectUpdate(BaseTask):
 
     model = ProjectUpdate
@@ -2321,7 +2321,7 @@ class RunProjectUpdate(BaseTask):
         return getattr(settings, 'AWX_PROOT_ENABLED', False)
 
 
-@task()
+@task(queue=get_local_queuename)
 class RunInventoryUpdate(BaseTask):
 
     model = InventoryUpdate
@@ -2589,7 +2589,7 @@ class RunInventoryUpdate(BaseTask):
             )
 
 
-@task()
+@task(queue=get_local_queuename)
 class RunAdHocCommand(BaseTask):
     '''
     Run an ad hoc command using ansible.
@@ -2779,7 +2779,7 @@ class RunAdHocCommand(BaseTask):
             isolated_manager_instance.cleanup()
 
 
-@task()
+@task(queue=get_local_queuename)
 class RunSystemJob(BaseTask):
 
     model = SystemJob
@@ -2853,7 +2853,7 @@ def _reconstruct_relationships(copy_mapping):
         new_obj.save()
 
 
-@task()
+@task(queue=get_local_queuename)
 def deep_copy_model_obj(
     model_module, model_name, obj_pk, new_obj_pk,
     user_pk, sub_obj_list, permission_check_func=None