In one embodiment, a system comprises a plurality of partitions that provide isolated operating environments for execution of software processes, wherein the plurality of partitions are arranged in a tiered manner with different partition types at different tiers, a data structure for representing the plurality of partitions, wherein the data structure comprises multiple nodes corresponding to the plurality of partitions and links between the nodes representing how the plurality of partitions are arranged in the tiers, and an arbiter software module for allocating resources between the plurality of partitions, wherein the arbiter software module receives requests to allocate resources to the plurality of partitions and traverses the data structure to determine which requests to satisfy.