A study of the impact of DNS resolvers on CDN performance using a causal approach
A study of the impact of DNS resolvers on CDN performance using a causal approach
复制标题
使用因果方法研究 DNS 解析器对 CDN 性能的影响
DOI：
10.1016/j.comnet.2016.06.023
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
M. Mellia
中科院分区：
文献类型：
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作者：
Hadrien Hours;E. Biersack;P. Loiseau;A. Finamore;M. Mellia
在互联网上发布的资源（如网页或视频）由其统一资源定位符（URL）引用。如果用户通过URL访问资源，则需要将URL的主机名部分转换为可路由的IP地址。此转换由域名系统服务（DNS）执行。当内容分发网络（CDN）用于在位于地理位置不同的多个服务器上托管流行对象的副本时，DNS也起着重要的作用。CDN使用DNS服务来推断客户端位置并将客户端请求定向到最佳服务器。虽然大多数互联网服务提供商（ISP）为客户提供DNS服务，但客户端可能会使用公共DNS服务。DNS服务的选择可能会影响客户端从给定CDN检索资源时的性能。在本文中，我们研究的影响下载性能的客户端使用的DNS服务的ISP或公共DNS服务由Google DNS提供。我们采用了因果关系的方法，暴露了不同的参数的结构依赖关系所使用的DNS服务的影响，我们展示了如何用贝叶斯网络来建模这些依赖关系。贝叶斯网络使我们能够解释和量化客户在使用其ISP的DNS服务时所看到的性能优势。我们还讨论了如何进一步提高客户端的性能。
Resources such as Web pages or videos that are published in the Internet are referred to by their Uniform Resource Locator (URL). If a user accesses a resource via its URL, the host name part of the URL needs to be translated into a routable IP address. This translation is performed by the Domain Name System service (DNS). DNS also plays an important role when Content Distribution Networks (CDNs) are used to host replicas of popular objects on multiple servers that are located in geographically different areas. A CDN makes use of the DNS service to infer client location and direct the client request to the optimal server. While most Internet Service Providers (ISPs) offer a DNS service to their customers, clients may instead use a public DNS service. The choice of the DNS service can impact the performance of clients when retrieving a resource from a given CDN. In this paper we study the impact on download performance for clients using either the DNS service of their ISP or the public DNS service provided by Google DNS. We adopt a causal approach that exposes the structural dependencies of the different parameters impacted by the DNS service used and we show how to model these dependencies with a Bayesian network. The Bayesian network allows us to explain and quantify the performance benefits seen by clients when using the DNS service of their ISP. We also discuss how the further improve client performance.