CRON stuck for multiple projects related to the activity_logger_message workaround for groups

In the MessageQueueCreator class from the activity_logger module we have a workaround active that waits for 5 seconds before creating the create_entitiy_action to support nodes in groups.

On multiple occasions across multiple projects (but not regularly) we have found that the CRON was stuck and had to be killed. The cause was that the activity logger message queue was in a Infinite loop:

INSERT INTO queue (name, data, created) VALUES ('activity_logger_message', 'a:1:{s:9:\\\"entity_id\\\";s:3:\\\"206\\\";}', '1494407324')

DELETE FROM queue WHERE  (item_id = '5838349')

SELECT data, created, item_id FROM queue q WHERE expire = 0 AND name = 'activity_logger_message' ORDER BY created, item_id ASC LIMIT 0, 1"

UPDATE queue SET expire='1494407354'\nWHERE  (item_id = '5838350') AND (expire = '0')

INSERT INTO queue (name, data, created) VALUES ('activity_logger_message', 'a:1:{s:9:\\\"entity_id\\\";s:3:\\\"206\\\";}', '1494407324')

DELETE FROM queue WHERE  (item_id = '5838350')

SELECT data, created, item_id FROM queue q WHERE expire = 0 AND name = 'activity_logger_message' ORDER BY created, item_id ASC LIMIT 0, 1"

UPDATE queue SET expire='1494407354'\nWHERE  (item_id = '5838351') AND (expire = '0')

INSERT INTO queue (name, data, created) VALUES ('activity_logger_message', 'a:1:{s:9:\\\"entity_id\\\";s:3:\\\"206\\\";}', '1494407324')

We are not sure how this Infinite loop could be activated because the node with id 206 was deleted and should not get passed the if statement if ($entity = Node::load($data['entity_id'])) { but it seems it did.