In certain aspects, the invention features a system and method for (1) receiving reservations for a first subset of computing resources of a distributed computing system (DCS), wherein each of the reservations specifies a time period, (2) allocating the first subset according to the reservations, (3) receiving requests for use of at least a second subset of the DCS's computing resources, wherein each of the requests specifies a time period, (4) determining whether enough unallocated resources are available to fulfill all of the requests, wherein the unallocated resources include the DCS's resources not allocated according to the reservations, (5) allocating resources according to the requests, if there are enough unallocated resources available, and (6) allocating resources in accordance with an allocation criteria if there are not enough unallocated resources available.