Round-Hashing for Data Storage: Distributed Servers and External-Memory Tables

TL;DR

This paper introduces round-hashing, a novel data distribution method for distributed servers and external-memory tables that significantly improves request serving speed and reduces data migration times.

Contribution

The paper presents round-hashing, a new hashing technique that minimizes rehashing and enhances performance in distributed data storage and external-memory table implementations.

Findings

Request serving speed is ten times faster than existing methods.

Round-hashing reduces data migration decision times.

Improves throughput in distributed data storage systems.

Abstract

This paper proposes round-hashing, which is suitable for data storage on distributed servers and for implementing external-memory tables in which each lookup retrieves at most a single block of external memory, using a stash. For data storage, round-hashing is like consistent hashing as it avoids a full rehashing of the keys when new servers are added. Experiments show that the speed to serve requests is tenfold or more than the state of the art. In distributed data storage, this guarantees better throughput for serving requests and, moreover, greatly reduces decision times for which data should move to new servers as rescanning data is much faster.