Scalable storage system

According to one embodiment, a storage system ( 400 ) may include a gateway service ( 402 ), metadata service ( 404 ) and storage service ( 406 ) that each provide different storage system functions. Each service ( 402, 404 and 406 ) may include a plurality of servers that are functionally de-coupled from one another. De-coupled servers may service requests without regard to the operation of other servers of the same service. Such a de-coupled arrangement can allow a storage system ( 400 ) to be scaled to meet increasing demands, as servers may be added to a system, on a service by service basis, without necessarily re-indexing stored information or reconfiguring multiple instances of a server application. Further, backup servers may be easily added to the system to enable fault tolerance. Servers of a particular service ( 402, 404 and 406 ) may be accessed according to a quality of service policy.