Mitigating Negative Impacts on DNS Caches Caused by Disposable Domain Names

DNS caches play an important role in DNS querying. However, the performance of DNS caches will be remarkably influenced by disposable domain names, which are generated by services of cloud storage, social networks, etc., and belong to a new class of misused case of DNS. In this paper, we proposed a novel solution named DC³ (Domain Classification and Cascade Cache) to mitigate the negative impact. Domain Classification adopts a classifier which is based on a long short-term memory (LSTM) network to prevent disposable domains from being cached. Cascade Cache is a refined cascade LRU policy considering cache size allocation to process the remaining disposable domains. By querying the real DNS traces collected from a large ISP network, experiment results show that this solution can detect disposable domain names and mitigate their negative impacts on DNS caches effectively. Specifically, in our dataset, 67.4% of all distinct domain names are detected as disposable domain names. Correspondingly, when getting rid of them by using this solution, we can raise the cache hit rate more than double.

I. Introduction

The Domain Name System (DNS) is an important part of critical Internet infrastructure, which aims to translate domain names into IP addresses. In translation process, DNS caches play an important role, aiming to accelerate the speed of domain name resolution. Additionally, we usually use cache hit rates to assess performance of DNS caches. High cache hit rates mean faster DNS responses.