Having multiple data stores that can potentially serve content is common in modern networked applications. Data stores often publish approximate summaries of their content to enable effective utilization. Since these summaries are not entirely accurate, forming an efficient access strategy to multiple data stores becomes a complex risk management problem. This paper formally models this problem as a cost minimization problem, while taking into account both access costs, the inaccuracy of the approximate summaries, as well as the penalties incurred by failed requests. We introduce practical algorithms with guaranteed approximation ratios and further show that they are optimal in various settings. We also perform an extensive simulation study based on real data and show that our algorithms are more robust than existing heuristics. That is, they exhibit near-optimal performance in various settings, whereas the efficiency of existing approaches depends upon system parameters that may change over time, or be otherwise unknown.

中文翻译：

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网络缓存的访问策略

在现代的网络应用程序中，拥有多个可以潜在地为内容提供服务的数据存储很常见。数据存储区通常会发布其内容的近似摘要，以实现有效利用。由于这些摘要并不完全准确，因此形成对多个数据存储的有效访问策略将成为一个复杂的风险管理问题。本文将这个问题正式建模为成本最小化问题，同时考虑了访问成本，近似摘要的不准确性以及失败请求所导致的罚款。我们介绍了具有保证近似率的实用算法，并进一步证明了它们在各种设置下均是最佳的。我们还基于真实数据进行了广泛的仿真研究，结果表明我们的算法比现有的启发式算法更健壮。那是，