@MASTERSTHESIS{ 2020:1557774594,
 	title = {A heuristic algorithm for minimizing server maintenance time and vulnerability surface on data centers},
 	year = {2020},
 	url = "http://tede2.pucrs.br/tede2/handle/tede/9522",
 	abstract = "Cost reduction and enhanced scalability boosted the adoption of cloud computing
 by multi-sized companies. To maintain the promised features, cloud operators perform
 several maintenance activities that range from removing dust accumulation to applying security
 patches on servers against vulnerabilities. The latter usually requires server update
 as soon as possible, as each instant servers need to wait for an update can indicate an opportunity
 for attackers to breach customers’ applications. Current solutions employ different
 approaches to minimize maintenance duration. However, they neglect the amount of time
 servers stay exposed to attacks. In this study, we first argue that only reducing maintenance
 time does not necessarily guarantee the efficiency of maintenance strategies on critical security
 patching scenarios, wherein safeguarding servers as soon as possible is the priority.
 Therefore, we propose a new metric called Vulnerability Surface, which aids operators in
 assessing the efficiency of maintenance strategies on critical security patching scenarios.
 Then, we present a heuristic algorithm that performs maintenance decisions to minimize the
 amount of time cloud servers remain exposed to attacks while reducing the amount of time
 necessary for performing server maintenance. We conducted a set of experiments against
 well-known strategies, and the results showed that the proposed solution achieves superior
 results regarding vulnerability surface, maintenance time, and the number of migrations per
 virtual machine.",
 	publisher = {Pontifícia Universidade Católica do Rio Grande do Sul},
 	scholl = {Programa de Pós-Graduação em Ciência da Computação},
 	note = {Escola Politécnica}
}