Patent attributes
A router of a block-level data storage service receives a request to generate a snapshot of a block device. The router, based on routing metadata for the block-level data storage service, identifies active metadata that indicates a first cell that may maintain the block device and alternate metadata that indicates a second cell that may maintain the block device. Based on a first state of the block device in the first cell, a second state of the block device in the second cell, and a predetermined set of rules defining operations corresponding to outcomes associated with the first state and the second state, the router determines which of the first cell and the second cell authoritatively maintains the block device. The router transmits the request to the appropriate cell in accordance with the predetermined set of rules.
