雲端大型多人線上遊戲下考量暫離玩家之資源配置方法

Abstract

近年來大型多人線上遊戲(MMOGs)吸引全世界成千上萬的玩家上線，且成為個人娛樂中非常重要的一部份。為了能夠支援更多的線上玩家，許多遊戲提供商(如OnLive)利用雲端計算的優點發展雲端遊戲。雖然雲端遊戲提供商從雲端計算上獲得強大的計算能力，如何有效的分配雲端資源(如虛擬機器)來滿足玩家的需求和有效的雲端資源利用是一項重要的研究議題。在此篇論文中，我們對大型多人線上遊戲提出一個考量暫離玩家(AFK players)的有效資源配置方法，利用暫離玩家僅需較低服務品質(QoS)的特性，降低配置給予他們的資源(如幀率)，從而支援更多的線上玩家。我們以魔獸世界做為個案研究，調查實際線上玩家的人數和暫離玩家的人數。我們利用類神經網路來預測玩家和暫離玩家的人數，並評估可額外支援的線上玩家的人數。然後，我們預測需使用的虛擬機器數量。依據真實遊戲數據之評估結果顯示，我們的資源配置方法能夠額外支援11.04%的線上玩家，且在46.05%的觀察時間內能在每一個魔獸世界的王國的一個遊戲區減少一台虛擬機器的使用，以支援更多玩家。因此，我們的方法能有效降低雲端資源的浪費，並提高資源的使用率。

Massively Multiplayer Online Games (MMOGs) are attracting millions of players from all over the world and become an important part of personal entertainments. To support more online players, many game providers (such as OnLive) take advantage of cloud computing to develop cloud gaming services. Although cloud gaming providers obtain powerful computing power from clouds, how to allocate cloud resources (e.g., virtual machines, VM) so as to meet player requirements and to efficiently utilize cloud resources is a key issue. In this paper, we propose an efficient resource provisioning scheme for MMOGs considering AFK (away from keyboard) players, RP-AFK, in game clouds. We leverage the characteristic of AFK players, which only need low QoS for gaming, to decrease the provision of resources (e.g., frame rates) to them and to support active online players. We used World of Warcraft (WoW), which is currently the world's most-subscribed MMORPG (Massively Multiplayer Online Role Player Game), as a case study to measure the total numbers of players and AFK players. We predicted the total numbers of players and AFK players by using neural networks, which can provide high prediction accuracy, and evaluated the number of extra online players supported. Then we predicted the number of VMs required. Evaluation results based on real game data show that the proposed RP-AFK can support 11.04% extra online players. One less VM can be used in a game zone of a WoW realm for 46.05% of the observed time. Therefore, the proposed scheme can reduce the waste of cloud resources and increase the resource utilization to support more players.