MOVING MEDIAN USAGE FREQUENCY BASED MAINTENANCE OF SERVER INSTANCES

A framework for maintaining a plurality of server instances in batches to ensure continuity of service is described herein. In accordance with one aspect, quantities of the server instances are selected in an order based on a usage frequency of the server instances with respect to a median usage frequency of the plurality of server instances. The selected server instances may be logically quarantined for maintenance, one batch at a time. Each batch of server instances may be returned to service when the server instances of the batch are successfully maintained while logically quarantining a next batch of server instances.