1. A distributed system, comprising: a plurality of first-tier entities; and a master entity in communication with each of the first-tier entities over a communication network, the master entity providing a single access point through which an administrator can submit commands to manage all of the entities, the master entity comprising: a processor; and memory storing an RPC (remote procedure call) client and a virtual slot table, the virtual slot table having a plurality of virtual slots, each virtual slot pointing to one of the first-tier entities, each first-tier entity being pointed to by at least one virtual slot, wherein the processor runs the RPC client to submit RPC requests to the first-tier entities in response to commands submitted by the administrator, and determines a destination first-tier entity for a given RPC request in response to which of the virtual slots the administrator submits a given command.