Fast LH

Abstract

Linear Hashing is a widely used and efficient version of extensible hashing. A distributed version of Linear Hashing is LH* that stores key-indexed records on up to hundreds of thousands of sites in a distributed system. LH* implements the dictionary data structure efficiently since it does not use a central component for the key-based operations of insertion, deletion, actualization, and retrieval and for the scan operation. LH* allows a client or a server to commit an addressing error by sending a request to the wrong server. In this case, the server forwards to the correct server directly or in one more forward operation. We discuss here methods to avoid the double forward, which is rare but might breach quality of service guarantees. We compare our methods with LH* P2P that pushes information about changes in the file structure to clients, whether they are active or not.