Category Archives: publications

Lamoth: A Message Dissemination Middleware for MMOGs in the Cloud [Poster]

Gascon-Samson J., Kemme, B., Kienzle, J. (2013) Lamoth: A Message Dissemination Middleware for MMOGs in the Cloud, NetGames 2013, Denver, USA
[Preprint] [Poster]

Abstract: Provisionning network resources for Massively Multiplayer Online Games (MMOGs) poses interesting challenges due to the fact that the load can greatly vary depending on the time or other in-game factors. In this paper, we propose Lamoth, a cloud middleware for MMOGs that provides an interface for in-game message dissemination. Lamoth handles the exchange of game messages between nodes by making use of an arbitrary number of off-the-shelve pub/sub servers deployed in the cloud depending on the game scenario. In order to evaluate our platform, we implement Lamoth on top of Mammoth, McGill’s research-oriented MMOG, and conduct extensive experiments by triggering situations which would cause networks bottlenecks. Our evaluations show that Lamoth can allow a MMOG to scale to high numbers of players and can properly handle extremely-demanding in-game situations if enough resources are provided.

Monitoring Large-Scale Location-Based Information Systems

Khan, H., Gascon-Samson, J., Kienzle, J., Kemme, B. (2015) Monitoring Large-Scale Location-Based Information Systems, IPDPS 2015, Hyderabad, India
> Acceptance ratio: 22% [Preprint]

Abstract: Monitoring the state of a distributed virtual world is challenging for several reasons: 1) the distributed information must be gathered in real-time without affecting the performance of the information system, 2) in large-scale systems it is impossible for a single node to collect and process all the data, 3) the vast information must be filtered and aggregated according to what the human observer wants to focus on, and 4) the point of interest of the observer can change frequently. In this paper we present and evaluate a non-intrusive monitoring middleware that addresses these challenges by dynamically partitioning the geographic map (e.g., of the virtual world or the game) in terms of map objects and (expected) state changes. We assign a different collector node to each of these partitions to collect and pre-process the data, and forward it to a central monitoring node. Furthermore, we provide mechanisms to efficiently filter and aggregate location changes, the pre-dominant changes in location-based information systems. We describe a specific monitoring setup that takes advantage of the replication model that is common in many virtual worlds and multiplayer games to collect the data. Finally, we present extensive performance results that show the trade-offs between scalability, precision, and real-time performance.

Watchmen: Scalable Cheat-Resistant Support for Distributed Multi-player Online Games

Yahyavi, A., Huguenin, K., Gascon-Samson, J., Kienzle, J., Kemme, B. (2013) Watchmen: Scalable Cheat-Resistant Support for Distributed Multi-player Online Games, ICDCS 2013, Philadelphia, USA
> Acceptance ratio: 13%  [Preprint]

Abstract: Multi-player online games are inherently distributed applications, and a wide range of distributed architectures have been proposed. However, only few successful commercial systems follow such approaches, even given their benefits, due to one main hurdle: the easiness with which cheaters can disrupt the game state computation and dissemination, perform illegal actions, or unduly gain access to sensitive information. The challenge is that any measures used to address cheating must meet the heavy scalability and tight latency requirements of fast paced games. We propose Watchmen, the first distributed scalable protocol designed with cheat detection and prevention in mind that supports fast paced games. It is based on a randomized dynamic proxy scheme for both the dissemination and verification of actions. Furthermore, Watchmen reduces the information exposed to players close to the minimum required to render the game. We build our proof-of-concept prototype on top of Quake III. We show that Watchmen, while scaling to hundreds of players and meeting the tight latency requirements of first person shooter games, is able to significantly reduce opportunities to cheat, even in the presence of collusion.