1. A method comprising: determining, using one or more computers, an original subset of a plurality of communicatively coupled nodes of a computing environment, the original subset comprising nodes currently unallocated to a job; selecting a job from a job queue; and determining that dimensions of the selected job are greater than a topology of the original subset; selecting one or more nodes from a second plurality of nodes, the second plurality being distinct from the original subset, wherein the selected one or more nodes from the second plurality are unavailable at the time of selecting; and adding the nodes selected from the second plurality to the original subset to satisfy the dimensions of the selected job after the nodes selected from the second plurality become available; and executing the selected job.