Solving key design issues for massively multiplayer online games on peer-to-peer architectures

Massively Multiplayer Online Games (MMOGs) are increasing in both popularity and scale on the Internet and are predominantly implemented by Client/Server architectures. While such a classical approach to distributed system design offers many benefits, it suffers from significant technical and commercial drawbacks, primarily reliability and scalability costs. This realisation has sparked recent research interest in adapting MMOGs to Peer-to-Peer (P2P) architectures. This thesis identifies six key design issues to be addressed by P2P MMOGs, namely interest management, event dissemination, task sharing, state persistency, cheating mitigation, and incentive mechanisms. Design alternatives for each issue are systematically compared, and their interrelationships discussed. How well representative P2P MMOG architectures fulfil the design criteria is also evaluated. It is argued that although P2P MMOG architectures are developing rapidly, their support for task sharing and incentive mechanisms still need to be improved. The design of a novel framework for P2P MMOGs, Mediator, is presented. It employs a self-organising super-peer network over a P2P overlay infrastructure, and addresses the six design issues in an integrated system. The Mediator framework is extensible, as it supports flexible policy plug-ins and can accommodate the introduction of new superpeer roles. Key components of this framework have been implemented and evaluated with a simulated P2P MMOG. As the Mediator framework relies on super-peers for computational and administrative tasks, membership management is crucial, e.g. to allow the system to recover from super-peer failures. A new technology for this, namely Membership-Aware Multicast with Bushiness Optimisation (MAMBO), has been designed, implemented and evaluated. It reuses the communication structure of a tree-based application-level multicast to track group membership efficiently. Evaluation of a demonstration application shows i that MAMBO is able to quickly detect and handle peers joining and leaving. Compared to a conventional supervision architecture, MAMBO is more scalable, and yet incurs less communication overheads. Besides MMOGs, MAMBO is suitable for other P2P applications, such as collaborative computing and multimedia streaming. This thesis also presents the design, implementation and evaluation of a novel task mapping infrastructure for heterogeneous P2P environments, Deadline-Driven Auctions (DDA). DDA is primarily designed to support NPC host allocation in P2P MMOGs, and specifically in the Mediator framework. However, it can also support the sharing of computational and interactive tasks with various deadlines in general P2P applications. Experimental and analytical results demonstrate that DDA efficiently allocates computing resources for large numbers of real-time NPC tasks in a simulated P2P MMOG with approximately 1000 players. Furthermore, DDA supports gaming interactivity by keeping the communication latency among NPC hosts and ordinary players low. It also supports flexible matchmaking policies, and can motivate application participants to contribute resources to the system

A Framework for Turn-Based Local Multiplayer Games

Mobile devices are present in people’s everyday lives and have gone from being a tool used purely to communicate. Currently they are also used as a means to entertain, by listening to music, watching videos or playing games. When it comes to games, these can be played alone (single player games) or with other people (multiplayer games), from strangers to family and friends. Local multiplayer games are a popular choice because they connect groups of physically close people to play and allow them to interact. However, there are some concerns to address. Local multiplayer games connect de vices but that alone isn’t enough to ensure correct game play. These games need to distribute the game state between the devices and solve the issues that ensue from that. These involve matching players, managing game state (making sure players get the cur rent state in a reasonable time frame, in order for the next moves to be performed), dealing with player inflow and outflow, among other problems. To reliably handle the aforementioned issues, in this thesis we propose Peppermint, a framework and runtime system to program local multiplayer games on the mobile edge. It was developed on top of Basil GardenBed, a data storage and dissemination system for the mobile edge developed at NOVA LINCS, that provides communication between devices. On the other hand, the challenges stemming from the games’ execution will be addressed by our framework, which are validated by the development and evaluation of one game according to a set of functional metrics. The results obtained during testing of our framework, mostly in a simulated setting, show that the framework is able to create and store matches, letting players join, leave and play in them. It will also discard the generated data when the match ends, so that the network doesn’t end up being cluttered with data that isn’t being accessed anymore. These characteristics constitute a framework has a set of core features that can be expanded in future work.Os dispositivos móveis estão presentes no dia-a-dia das pessoas e deixaram de ser apenas utilizados para comunicar. Presentemente são também usados como meio de entreteni mento, ao permitirem ouvir música, ver vídeos ou jogar jogos. Em relação a jogos, estes podem ser apenas para um jogador, ou podem ser jogados por várias pessoas (jogos mul tijogador), desde desconhecidos a família e amigos. Os jogos multijogador locais são uma escolha popular porque permitem que grupos de pessoas próximas fisicamente se juntem e interajam. No entanto, existem problemas a resolver. Os jogos multijogador locais conectam dis positivos mas apenas isso não é suficiente para garantir a sua correcção. Os jogos necessi tam de distribuir o seu estado entre os dispositivos e resolver as questões que decorrem disso. Estas envolvem agrupar jogadores, gerir o estado do jogo (ao garantir que os joga dores recebem o estado mais recente atempadamente, para que os próximos movimentos possam ser efectuados), lidar com o fluxo de jogadores, entre outros problemas. Para resolver os problemas mencionados, nesta tese apresentamos Peppermint, uma infraestrutura e sistema de execução para implementar jogos multijogador locais em dispositivos ligados a uma rede na mobile edge. Foi desenvolvido sobre o sistemaBasil GardenBed, um sistema de armazenamento e disseminação de dados na mobile edge de senvolvido no NOVA LINCS, que fornece comunicação entre dispositivos. Por outro lado, os desafios resultantes da execução dos jogos são endereçados pela nossa infraestrutura, validados pelo desenvolvimento e avaliação de um jogo de acordo com um conjunto de métricas relativas ao seu funcionamento. Os resultados, predominantemente obtidos em ambiente simulado, mostram que a infraestrutura permite criar e armazenar partidas, deixando outros jogadores entrar, sair e jogar. Também elimina os dados criados quando estas terminam, para que a rede não fique preenchida com dados que já não serão acedidos. Tudo isto forma uma infraestrutura com um conjunto de características básicas que podem ser expandidas em trabalho futuro

Analysis of Matchmaking Optimization Systems Potential in Mobile eSports

Matchmaking systems are one of the core features of experience in online gaming. They influence player satisfaction, engagement, and churn risk. The paper looks into the current state of the theoretical and practical implementation of such systems in the mobile gaming industry. We propose a basic classification of matchmaking systems into random and quasi-random, skill-based, role-based, technical factor-based, and engagement based. We also offer an analysis of matchmaking systems in 16 leading mobile Esport games. The dominant industry solution is skill and rank based systems with a different level of skill depth measurement. In the further part of the paper, we present a theoretical model of engagement and a time-optimized model

Distributed game

Dissertação de mestrado em Engenharia InformáticaThe demand for online games has risen over the years, expanding multiplayer support for new and different game genres. Among them are Massively Multiplayer Online games, one of the most popular and successful game types in the industry. Nowadays, this industry is thriving, evolving alongside technological advancements and producing billions in revenue, making it an economic importance. However, as the complexity of these games grows, so do the challenges they face when constructing them. This dissertation aims to implement a distributed game, through a proof of concept or an existing game, using a distributed architecture to acquire knowledge in the construction of such complex systems and the effort involved in dealing with consistency, maintaining communication infrastructure, and managing data in a distributed way. It is also intended that this project implements multiple mechanisms capable of autonomously helping manage and maintain the correct state of the system. To evaluate the proposed solution, a detailed analysis is carried out with performance benchmark analysis, stress testing, followed by an examination of its security, scalability, and distribution’s resilience. Overall, the present research work allowed for a greater understanding of the technologies and approaches used in constructing a gaming system, establishing a new set of development opportunities to be further investi gated upon the constructed solution.A procura por jogos online aumentou ao longo dos anos, expandindo o suporte multiplayer para novos e diferentes géneros. Entre estes estão os jogos Massively Multiplayer Online, um dos tipos de jogos mais populares e bem-sucedidos na indústria. Atualmente, esta indústria está a prosperar, evoluindo com os avanços tecnológicos e gerando milhares de milhões em receita, tornando-se uma importância económica. Porém, à medida que a complexidade destes jogos aumenta, também aumenta os problemas encontrados durante a sua construção. Esta dissertação tem como objetivo implementar um jogo distribuído, através de uma prova de conceito ou um jogo existente, usando uma arquitetura distribuída a fim de adquirir conhecimento na construção destes sistemas complexos e o esforço envolvido em lidar com consistência, manter a infraestrutura de comunicação e gerir dados de maneira distribuída. Para isto, é pretendido que este projeto também implemente vários mecanismos capazes de, forma autônoma, ajudar a gerir e manter o correto estado do sistema. Para avaliar o solução proposta, uma análise detalhada é realizada sobre o desempenho, segurança, escalabilidade e resiliência da distribuição do sistema. De forma geral, o presente trabalho de pesquisa permitiu uma maior compreensão das tecnologias e abordagens utilizadas na construção de um sistema de jogos, estabelecendo um novo conjunto de oportunidades de desenvolvimento a serem investigadas sobre a solução construída

GameOn: P2p gaming on public transport

Ministry of Education, Singapore under its Academic Research Funding Tier

The Importance of Matchmaking in League of Legends and its Effects on Users

Massively multiplayer online games have become a large industry with millions of users playing every day. Matchmaking is used to group players in a fair game for multiplayer online video games. In this paper, we examine how well matchmaking systems create matches that are enjoyable for players in the popular multiplayer online game League of Legends. We collected data about the matchmaking system of League of Legends by surveying players before and after a game and collecting statistics about their games. We analyzed this data and came to several conclusions: queue times rise with rank but are generally quite low, the main factor reported to affect the game outcome is player skill, and players generally enjoy games where their team is better or the game is even