77 research outputs found
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
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Distributed virtual environment scalability and security
Distributed virtual environments (DVEs) have been an active area of research and engineering for more than 20 years. The most widely deployed DVEs are network games such as Quake, Halo, and World of Warcraft (WoW), with millions of users and billions of dollars in annual revenue. Deployed DVEs remain expensive centralized implementations despite significant research outlining ways to distribute DVE workloads.
This dissertation shows previous DVE research evaluations are inconsistent with deployed DVE needs. Assumptions about avatar movement and proximity - fundamental scale factors - do not match WoW’s workload, and likely the workload of other deployed DVEs. Alternate workload models are explored and preliminary conclusions presented. Using realistic workloads it is shown that a fully decentralized DVE cannot be deployed to today’s consumers, regardless of its overhead.
Residential broadband speeds are improving, and this limitation will eventually disappear. When it does, appropriate security mechanisms will be a fundamental requirement for technology adoption.
A trusted auditing system (“Carbon”) is presented which has good security, scalability, and resource characteristics for decentralized DVEs. When performing exhaustive auditing, Carbon adds 27% network overhead to a decentralized DVE with a WoW-like workload. This resource consumption can be reduced significantly, depending upon the DVE’s risk tolerance.
Finally, the Pairwise Random Protocol (PRP) is described. PRP enables adversaries to fairly resolve probabilistic activities, an ability missing from most decentralized DVE security proposals.
Thus, this dissertations contribution is to address two of the obstacles for deploying research on decentralized DVE architectures. First, lack of evidence that research results apply to existing DVEs. Second, the lack of security systems combining appropriate security guarantees with acceptable overhead
Design Issues for Peer-to-Peer Massively Multiplayer Online Games.
Massively Multiplayer Online Games (MMOGs) are increasing in both popularity and scale, and while classical Client/Server (C/S) architectures convey some benefits, they suffer from significant technical and commercial drawbacks. This realisation has sparked intensive research interest in adapting MMOGs to Peer-to-Peer (P2P) architectures. This paper articulates a comprehensive set of six design issues to be addressed by P2P MMOGs, namely Interest Management (IM), game event dissemination, Non-Player Character (NPC) host allocation, game state persistency, cheating mitigation and incentive mechanisms. Design alternatives for each issue are systematically compared, and their interrelationships discussed. We further evaluate how well representative P2P MMOG architectures fulfil the design criteria
Re-engineering jake2 to work on a grid using the GridGain Middleware
With the advent of Massively Multiplayer Online Games (MMOGs), engineers and
designers of games came across with many questions that needed to be answered such
as, for example, "how to allow a large amount of clients to play simultaneously on the
same server?", "how to guarantee a good quality of service (QoS) to a great number
of clients?", "how many resources will be necessary?", "how to optimize these resources
to the maximum?". A possible answer to these questions relies on the usage of grid
computing.
Taking into account the parallel and distributed nature of grid computing, we can say
that grid computing allows for more scalability in terms of a growing number of players,
guarantees shorter communication time between clients and servers, and allows for a
better resource management and usage (e.g., memory, CPU, core balancing usage, etc.)
than the traditional serial computing model.
However, the main focus of this thesis is not about grid computing. Instead, this
thesis describes the re-engineering process of an existing multiplayer computer game,
called Jake2, by transforming it into a MMOG, which is then put to run on a grid
Dynamic Load Balancing for Massively Multiplayer Online Games
In recent years, there has been an important growth of online gaming. Today’s Massively Multiplayer Online Games (MMOGs) can contain millions of synchronous players scattered across the world and participating with each other within a single shared game. Traditional Client/Server architectures of MMOGs exhibit different problems in scalability, reliability, and latency, as well as the cost of adding new servers when demand is too high. P2P architecture provides considerable support for scalability of MMOGs. It also achieves good response times by supporting direct connections between players. This thesis proposes a novel hybrid Peer-to-Peer architecture for MMOGs and a new dynamic load balancing for massively multiplayer online games (MMOGs) based this hybrid Peer-to-Peer architecture. We have divided the game world space into several regions. Each region in the game world space is controlled and managed by using both a super-peer and a clone-super-peer. The region's super-peer is responsible for distributing the game update among the players inside the region, as well as managing the game communications between the players. However, the clone-super-peer is responsible for controlling the players' migration from one region to another, in addition to be the super-peer of the region when the super-peer leaves the game. In this thesis, we have designed and simulated a static and dynamic Area of Interest Management (AoIM) for MMOGs based on both architectures hybrid P2P and client-server with the possibility of players to move from one region to another. In this thesis also, we have designed and evaluated the static and dynamic load balancing for MMOGs based on hybrid P2P architecture. We have used OPNET Modeler 18.0 to simulate and evaluate the proposed system, especially standard applications, custom applications, TDMA and RX Group. Our dynamic load balancer is responsible for distributing the load among the regions in the game world space. The position of the load balancer is located between the game server and the regions. The results, following extensive experiments, show that low delay and higher traffic communication can be achieved using both of hybrid P2P architecture, static and dynamic AoIM, dynamic load balancing for MMOGs based on hybrid P2P system
Open software to innovation: the critical success factors of massively multiplayer online role playing games (MMORPG) in China and Ireland.
This project investigates the factors leading to the success of China’s Massively Multiplayer Online Role Playing Games (MMORPG) market and gives an analysis of how Open source has contributed to these success factors. It then will look at how the use of open source is mirrored in Ireland’s market for example, the software sector to see if the same factors are apparent or there are indicators of these. Knowledge Management plays a very important role for fasten the innovation of Open source software development in China
Performance analysis of cloud-based cve communication architecture in comparison with the traditional client server, p2p and hybrid models
Gital et al. (2014) proposed a cloud based
communication architecture for improving efficiency of
collaborative virtual environment (CVE) systems in
terms of Scalability and Consistency requirements. This
paper evaluates the performance of the proposed CVE
architecture. The metrics use for the evaluation is
response time. We compare the cloud-based architecture
to the traditional client server and peer-2–peer (P2P)
architecture. The comparison was implemented in the
CVE systems. The comparative simulation analysis of
the results suggested that the CVE architecture based on
cloud computing can significantly improve the
performance of the CVE system
Enhancing trustability in MMOGs environments
Massively Multiplayer Online Games (MMOGs; e.g., World of Warcraft), virtual worlds
(VW; e.g., Second Life), social networks (e.g., Facebook) strongly demand for more
autonomic, security, and trust mechanisms in a way similar to humans do in the real
life world. As known, this is a difficult matter because trusting in humans and organizations
depends on the perception and experience of each individual, which is difficult to
quantify or measure. In fact, these societal environments lack trust mechanisms similar
to those involved in humans-to-human interactions. Besides, interactions mediated
by compute devices are constantly evolving, requiring trust mechanisms that keep the
pace with the developments and assess risk situations.
In VW/MMOGs, it is widely recognized that users develop trust relationships from their
in-world interactions with others. However, these trust relationships end up not being
represented in the data structures (or databases) of such virtual worlds, though they
sometimes appear associated to reputation and recommendation systems. In addition,
as far as we know, the user is not provided with a personal trust tool to sustain his/her
decision making while he/she interacts with other users in the virtual or game world.
In order to solve this problem, as well as those mentioned above, we propose herein a
formal representation of these personal trust relationships, which are based on avataravatar
interactions. The leading idea is to provide each avatar-impersonated player
with a personal trust tool that follows a distributed trust model, i.e., the trust data is
distributed over the societal network of a given VW/MMOG.
Representing, manipulating, and inferring trust from the user/player point of view certainly
is a grand challenge. When someone meets an unknown individual, the question
is “Can I trust him/her or not?”. It is clear that this requires the user to have access to
a representation of trust about others, but, unless we are using an open source VW/MMOG,
it is difficult —not to say unfeasible— to get access to such data. Even, in an open
source system, a number of users may refuse to pass information about its friends, acquaintances,
or others. Putting together its own data and gathered data obtained from
others, the avatar-impersonated player should be able to come across a trust result
about its current trustee. For the trust assessment method used in this thesis, we use
subjective logic operators and graph search algorithms to undertake such trust inference
about the trustee. The proposed trust inference system has been validated using
a number of OpenSimulator (opensimulator.org) scenarios, which showed an accuracy
increase in evaluating trustability of avatars.
Summing up, our proposal aims thus to introduce a trust theory for virtual worlds, its
trust assessment metrics (e.g., subjective logic) and trust discovery methods (e.g.,
graph search methods), on an individual basis, rather than based on usual centralized
reputation systems. In particular, and unlike other trust discovery methods, our methods
run at interactive rates.MMOGs (Massively Multiplayer Online Games, como por exemplo, World of Warcraft),
mundos virtuais (VW, como por exemplo, o Second Life) e redes sociais (como por exemplo,
Facebook) necessitam de mecanismos de confiança mais autónomos, capazes de
assegurar a segurança e a confiança de uma forma semelhante à que os seres humanos
utilizam na vida real. Como se sabe, esta não é uma questão fácil. Porque confiar em
seres humanos e ou organizações depende da percepção e da experiência de cada indivíduo,
o que é difícil de quantificar ou medir à partida. Na verdade, esses ambientes
sociais carecem dos mecanismos de confiança presentes em interacções humanas presenciais.
Além disso, as interacções mediadas por dispositivos computacionais estão em
constante evolução, necessitando de mecanismos de confiança adequados ao ritmo da
evolução para avaliar situações de risco.
Em VW/MMOGs, é amplamente reconhecido que os utilizadores desenvolvem relações
de confiança a partir das suas interacções no mundo com outros. No entanto, essas relações
de confiança acabam por não ser representadas nas estruturas de dados (ou bases
de dados) do VW/MMOG específico, embora às vezes apareçam associados à reputação
e a sistemas de reputação. Além disso, tanto quanto sabemos, ao utilizador não lhe
é facultado nenhum mecanismo que suporte uma ferramenta de confiança individual
para sustentar o seu processo de tomada de decisão, enquanto ele interage com outros
utilizadores no mundo virtual ou jogo. A fim de resolver este problema, bem como
os mencionados acima, propomos nesta tese uma representação formal para essas relações
de confiança pessoal, baseada em interacções avatar-avatar. A ideia principal
é fornecer a cada jogador representado por um avatar uma ferramenta de confiança
pessoal que segue um modelo de confiança distribuída, ou seja, os dados de confiança
são distribuídos através da rede social de um determinado VW/MMOG.
Representar, manipular e inferir a confiança do ponto de utilizador/jogador, é certamente
um grande desafio. Quando alguém encontra um indivíduo desconhecido, a
pergunta é “Posso confiar ou não nele?”. É claro que isto requer que o utilizador tenha
acesso a uma representação de confiança sobre os outros, mas, a menos que possamos
usar uma plataforma VW/MMOG de código aberto, é difícil — para não dizer impossível
— obter acesso aos dados gerados pelos utilizadores. Mesmo em sistemas de código
aberto, um número de utilizadores pode recusar partilhar informações sobre seus amigos,
conhecidos, ou sobre outros. Ao juntar seus próprios dados com os dados obtidos de
outros, o utilizador/jogador representado por um avatar deve ser capaz de produzir uma
avaliação de confiança sobre o utilizador/jogador com o qual se encontra a interagir.
Relativamente ao método de avaliação de confiança empregue nesta tese, utilizamos
lógica subjectiva para a representação da confiança, e também operadores lógicos da
lógica subjectiva juntamente com algoritmos de procura em grafos para empreender
o processo de inferência da confiança relativamente a outro utilizador. O sistema de
inferência de confiança proposto foi validado através de um número de cenários Open-Simulator (opensimulator.org), que mostrou um aumento na precisão na avaliação da
confiança de avatares.
Resumindo, a nossa proposta visa, assim, introduzir uma teoria de confiança para mundos
virtuais, conjuntamente com métricas de avaliação de confiança (por exemplo, a
lógica subjectiva) e em métodos de procura de caminhos de confiança (com por exemplo,
através de métodos de pesquisa em grafos), partindo de uma base individual, em
vez de se basear em sistemas habituais de reputação centralizados. Em particular, e ao
contrário de outros métodos de determinação do grau de confiança, os nossos métodos
são executados em tempo real
Clouds + Games: A multifaceted approach
The computer game landscape is changing: people play games on multiple computing devices with heterogeneous form-factors, capability, and connectivity. Providing high playability on such devices concurrently is difficult. To enhance the gaming experience, designers could leverage abundant and elastic cloud resources, but current cloud platforms aren't optimized for highly interactive games. Existing studies focus on streaming-based cloud gaming, which is a special case for the more general cloud game architecture. The authors explain how to integrate techniques from the cloud and game research communities into a complete architecture for enhanced online gaming quality. They examine several open issues that appear only when clouds and games are put together. © 2014 IEEE
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