1. A system for monitoring a plurality of storage systems comprising: an interface specifying a set of methods for using at least one storage system; an implementation of the interface for each of the plurality of storage systems, wherein at least one of the implementations of the interface is configured to process a plurality of requests; and a performance monitor configured to monitor performance of requests for at least one of a plurality of classes of requests; wherein the system is implemented using at least one processing device comprising a processor coupled to a memory.