Reliable Data Sharing in Wide Area Gigabit Networked Databases

本项目的目标是研究高速网络的新功能对数据管理协议的设计和性能的影响。特别是，重点放在高速广域网(WAN)上，其中传播延迟是主要的通信成本，大量数据的迁移不是问题，并且可以获得有效的多播和对网络服务质量(QOS)参数的保证。在这个项目中，正在评估现有的并发控制、提交和恢复协议在新的网络假设下的性能可扩展性。此外，正在开发新的协议，其利用多播能力并提供诸如有界的端到端分组延迟和分组丢失之类的服务质量保证，来利用巨大的带宽并最小化消息的顺序阶段的数量。同时，由于需要扩展到数千个客户端和服务器(并非所有客户端和服务器在任何给定时间都可运行)，新的广域网数据管理协议旨在以协作方式实现更高的站点自主性，减少全局同步并支持断开连接的操作。在不同的场景下，使用计算机模拟对各种协议进行了经验评估。预计这项研究的结果将更好地洞察数据库和网络技术之间的协同作用。这反过来将促进未来高性能广域网数据服务器系统的部署，这些系统是必要基础设施的一部分，将支持重要的国家和世界范围的应用程序，如电子商务和其他基于网络的应用程序。Http://www.cs.pitt.edu/admt/projects/wands.html

This project's goal is to study the impact of the new capabilities of high-speed networks on the design and performance of data management protocols. In particular, the focus is on high-speed wide-area networks (WANs) where the propagation latency is the dominant communication cost, the migration of large amounts of data is not an issue, and efficient multicasting and guarantees on network Quality of Service (QoS) parameters are available. In this project, existing concurrency control, commit and recovery protocols are being evaluated with respect to performance scalability under the new network assumptions. Further, new protocols are being developed that utilize the huge bandwidth and minimize the number of sequential phases of messages exploiting the multicasting capability and the provision of QoS guarantees such as bounded end-to-end packet delay and packet loss. At the same time, because of the need to scale to thousands of clients and servers, not all of which may be operational at any given time, the new WAN data management protocols are designed to achieve higher site autonomy in a cooperative manner, reducing global synchronization and supporting disconnected operations. The various protocols are empirically evaluated using computer simulation under different scenarios. The results of this research are expected to provide a better insight into the synergy between database and network technologies. This, in turn, will facilitate the deployment of future high performance WAN data server systems which are part of the necessary infrastructure that will support important nation- and world-wide applications such as electronic commerce and other web-based applications. http://www.cs.pitt.edu/admt/projects/wands.html