1,721,030 research outputs found
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
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
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
ASSIST demo: a High Level, High Performance, Portable, Structured Parallel Programming Environment at Work
No full textIntegrating 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
High-Performance Data Mining with Skeleton-based Structured Parallel Programming
No full textWe show ho to apply a structured parallel programming (SPP) methoxAxfi0 basedo skeleto5 to data mining (DM)pro04#4x repo4#4x several resultsabol threecoee05fi used mining techniques, namelyasso0AfijjB rules,decisio treeinductio and spatial clustering. We analyze the structural patternscoter to theseapplicatio#4 loplic atapplicatio perfoc mance andso0A4jj engineering e#ciency. Our aim isto clearly state what features a SPP enviroBB5j shoBB haveto be usefulfo parallel DM. Within theskeleto0#4jfij PPE SkIE that we have develo/0# we study the di#erent patternso data accesso parallel implementatio# o Aprioem C4.5 and DBSCAN. We needto address largepartitiox reads, frequent and sparse accessto smallblol0A as well as an irregular mixo small and large transfers,to allo e#cient develo0BB5 o applicatioj o huge databases. We examine theadditio o ano5fijxI0#44B/ nent interfaceto theskeleto structuredmoruc to simplify thedevelox0#4 o envirox0#4A integrated, parallel DM applications
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