Revert "Apply migration flag check to task manager"

This reverts commit a0910eb6de.

awx/main/utils/db.py

@@ -1,16 +1,8 @@
 # Copyright (c) 2017 Ansible by Red Hat
 # All Rights Reserved.
 
-import logging
 from itertools import chain
 
-from django.core.cache import cache
-from django.db.migrations.executor import MigrationExecutor
-from django.db import connection
-
-
-logger = logging.getLogger('awx.main.utils.db')
-
 
 def get_all_field_names(model):
     # Implements compatibility with _meta.get_all_field_names
@@ -22,21 +14,3 @@ def get_all_field_names(model):
         # GenericForeignKey from the results.
         if not (field.many_to_one and field.related_model is None)
     )))
-
-
-def migration_in_progress_check_or_relase():
-    '''A memcache flag is raised (set to True) to inform cluster
-    that a migration is ongoing see main.apps.MainConfig.ready
-    if the flag is True then the flag is removed on this instance if
-        models-db consistency is observed
-    effective value of migration flag is returned
-    '''
-    migration_in_progress = cache.get('migration_in_progress', False)
-    if migration_in_progress:
-        executor = MigrationExecutor(connection)
-        plan = executor.migration_plan(executor.loader.graph.leaf_nodes())
-        if not bool(plan):
-            logger.info('Detected that migration finished, migration flag taken down.')
-            cache.delete('migration_in_progress')
-            migration_in_progress = False
-    return migration_in_progress