Abstract: Systems and methods are disclosed for handling requests to create multiple volumes with an expected usage correlation on a block storage service. Rather than handling each request to create a volume independently, embodiments described herein can handle the request in bulk, quickly determining whether the request as a whole can be handled at the system. In one embodiment, the service allows for oversubscription of use on hosts, as well as parallelization of placement decisions, by rejecting placement requests when a number of possible hosts for a volume within a requested set falls below a candidate set size, which is determined based on factors such as a number of requested volumes and an expected accuracy of state information for the service at a placement engine within a distributed set of engines.

Abstract: Systems and methods are disclosed for handling requests to create multiple volumes with an expected usage correlation on a block storage service. Rather than handling each request to create a volume independently, embodiments described herein can handle the request in bulk. In one embodiment, the service allows for oversubscription of use on hosts, as well as parallelization of placement decisions, by distributing requests among a set of parallelized placement engines. Each engine can distribute its subset of volumes at least partly randomly among a candidate set of volumes, with the size of the candidate set selected based on a total number of volumes. This distribution mechanism can ensure distribution of volumes without requiring centralized placement of the volumes.