A computing resource service provider may provide computing instances organized into logical groups, such as auto-scale groups. Computing instances assigned to an auto-scale group may be associated with one or more load balancers configured to direct traffic to the computing instances. Furthermore, customers of the computing resource service provider may add or remove load balancer from the auto-scale groups. A background process may be used to add and remove computer instances of the auto-scale group form the load balancers customers are attempting to have added or removed.