Reusing dynamic redistribution to eliminate cross-server operations and maintain semantics while scaling storage systems

Distributed file systems that scale by partitioning files and directories among a collection of servers inevitably encounter cross-server operations. A common example is a rename that moves a file from a directory managed by one server to a directory managed by another. Systems that provide the same semantics for cross-server operations as for those that do not span servers traditionally implement dedicated protocols for these rare operations. This thesis explores an alternate, simpler, approach that exploits the existence of dynamic redistribution functionality (e.g., for load balancing, incorporation of new servers, and so on). When a client request would involve files on multiple servers, the system can redistribute those files onto one server and have it service the request. Although such redistribution is more expensive than a dedicated cross-server protocol, preliminary analysis of NFS traces indicates that such operations are extremely rare in file system workloads. Thus, when dynamic redistribution functionality exists in the system, cross-server operations can be handled with very little additional implementation complexity.