Data Storage Management in a Distributed Database with Deterministic Limited Communications Windows Between Data Storage Nodes

摘要

An orbital service model allows data to be collected, stored and used on different nodes comprising an ad-hoc system where provider craft supply services to consumer craft. Ad-hoc networks and provider-consumer relationships are commonly used in various applications on Earth. The deterministic movement of spacecraft, however, allows the ad-hoc network and service providing model to operate in a different way than would be typical in most terrestrial ad-hoc networks. While long periods of no direct node-to-node connectivity may exist, the periods of connectivity are pre-known based on orbital parameters. Additionally, paths for indirect connectivity can be identified and evaluated for cost effectiveness. This paper presents a data management approach for an orbital computing ad-hoc system. Algorithms for determining where data should be stored (identification of most useful point of storage, whether multiple copies are justified) and how movement should be affected (transfer scheduling, replication, etc.) are presented and evaluated.