Fast recovery of backup cloud gateway following crash without garbage collection

摘要

In a cloud storage system, fast recovery from a crash of a cloud gateway or the cloud storage is afforded without the necessity of traditional garbage collection. Data objects are each broken up into a plurality of chunk objects that are prefixed with a unique non-repeating forever increasing generation number that is incremented for each different data object. The chunk objects of a particular data object are identified and listed in a manifest file that is also associated with that generation number. Upon a crash of either the cloud gateway or the cloud storage, a query identifies the cloud and deletes all orphaned chunk objects prefixed by and all manifest files associated with the prevailing generation number at the time of the crash. The deleted chunk objects and manifest files are regenerated and restored to cloud storage to return to consistency.