1,941 research outputs found
Il caso Carlini
No full textA note introducing writer Pietro Carlini (1924-78) and his posthumous novel "L'Ideal"
Reducing Server Load in MMOG via P2P Gossip
No full textA fundamental problem for the development of Massively Multiplayer Online Games (MMOGs) is the definition
of a mechanism supporting interest management, i.e. determining all the entities of the virtual world that are relevant for a given peer. To this end, we propose a hybrid architecture combining centralized and P2P solutions. Our proposal exploits a P2P gossip-based approach supporting a best-effort resolution of
interest management, so that it can be mostly supported through the P2P overlay, with minimal intervention of a centralized entity
Integration of P2P and Clouds to Support Massively Multiuser Virtual Environments
No full textMassively Multiuser Virtual Environments (MMVEs) are attracting millions of players from all over the world. Currently used Client/Server infrastructures and technologies are reaching their limits of flexibility and scalability.
We propose an approach that combines the technological advantages of two different paradigms, namely P2P networking and Cloud Computing. Our proposal leverages known P2P techniques like Virtual Nodes and consistent hashing, as well as separate overlays for different purposes, e.g. interest and object management.
We propose combining these techniques with the definition of a specific role in the overlay for Cloud-based, trusted resources. This enables the distribution of the MMVE on top of a mix of Cloud and user resources. The solution outlined allows building key-value distributed storage systems that can resize at run-time (elasticity) and provide scalability and load balancing features to the MMVE platform
Flexible load distribution for hybrid distributed virtual environments
No full textThis paper proposes an architecture for Distributed Virtual Environments (DVEs) integrating cloud and peer nodes. We define the overall structure of the architecture and propose a flexible strategy to distribute the load due to the management of the entities of the DVE. The proposed approach takes into account the utilisation of the nodes, the economical cost due to their use of bandwidth, and their probability of failure. A greedy heuristics is exploited to reduce the computational cost of the algorithm in order to maintain a fair interactivity level to the end user of the DVE. A mobility model generating realistic Second Life traces is exploited to evaluate our algorithm. The experimental results show the effectiveness of our approach
Integrating Centralized and P2P Architectures to Support Interest Management in Massively Multiplayer On-Line Games
No full textA fundamental problem for the development of peer-to-peer (P2P) distributed virtual environments, like massively multiplayer on-line games, is the definition of an overlay supporting interest management, that is, determining all the entities of the virtual world that are relevant for a given player. To this end, this paper proposes a gossip-based approach that considers the coverage of the area of interest of peers as the guiding principle for the definition of the P2P overlay and its maintenance. The resulting overlay provides a support for a best-effort resolution of interest management, mostly supported through communications on the P2P overlay, with minimal intervention of a centralized entity. The paper presents a set of extensive simulations based on realistic mobility traces. The experimental results show the effectiveness of gossiping for the construction and maintenance of a best-effort overlay for interest management
Evaluating Compass Routing Based AOI-Cast by MOGs Mobility Models
No full textThe increasing popularity of Multiplayer Online Games
(MOGs) is revealing a huge interest from the research com-
munity. Many solutions exploiting P2P technologies have
been proposed in order to overtake the limits of the cen-
tralized infrastructures. These solutions are based on the
denition of a proper dynamic P2P overlay and exploit the
concept of Area of Interest (AOI) to lter the information
relevant for each player. An AOI-cast mechanism denes
a spanning tree over the AOI so that the information gen-
erated by a player is propagated to all the players located
in its AOI. Although most proposals are founded on solid
basis, they are often validated through players' movement
patterns that result dierent form those of a real MOG.
This paper presents a set of mobility models for the eval-
uation of the AOI-cast. Together with classical mobility
models, mobility patterns derived from popular MOGs, i.e.
World of Warcraft(WoW) and Second Life(SL), are also pre-
sented. A novel mobility mobility model taking into account
the WoW battleground scenarios is proposed. The proposed
mobility models are exploited to evaluate an AOI-cast algo-
rithm based on the denition of a Delaunay overlay. The
experiments show that the AOI-cast mechanism we propose
can be exploited in real scenarios only when a set of condi-
tions hold
Probabilistic Dropping in Push and Pull Dissemination over Distributed Hash Tables
No full textDynamic information management via Distributed Hash Tables (DHT) is an important problem which revolves around the trade-off between data freshness and the overhead due to information updates. We propose two different algorithms based on information pull and information push models, that enable dynamic information dissemination with low overhead over a DHT. We exploit the concept of popularity of specific items, which is evaluated by performing a real-time analysis of the query distribution, and allows to decrease a significant fraction of messages without impairing the query resolution process. We have measured the overhead savings and compared the performance of the two approaches by extensive simulations using real workload traces
AOI-cast by Compass Routing in Delaunay Based DVE Overlays
No full textThis paper presents a AOI cast strategy for P2P Distributed Environments which is exploited to notify the position updates of a peer P, i.e. its heartbeats, to all the peers located in its Area of Interest. An algorithm for the construction of a spanning tree covering all the peers is presented. The algorithm exploits the properties of Delaunay Triangulations to reduce the traffic load on the P2P overlay. The paper presents a set of formal results which hold when the AOI is a circular area and the root of the tree is at the center of the area. The algorithm is then refined to take into account possible inconsistencies among the local views of the peers due to the latency of the underlying network. A set of experimental results are presented
Studio e messa a punto di una metodologia per l’impiego di oli esausti vegetali ed animali come fitofarmaci in sostituzione degli oli bianchi di idrocarburi
No full textCentro Interuniversitario di Ricerca per i Paesi in via di Sviluppo, Università degli Studi di Roma "La Sapienza
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