2,063 research outputs found
Dynamic Resource Management in Clouds: A Probabilistic Approach
Dynamic resource management has become an active area of research in the
Cloud Computing paradigm. Cost of resources varies significantly depending on
configuration for using them. Hence efficient management of resources is of
prime interest to both Cloud Providers and Cloud Users. In this work we suggest
a probabilistic resource provisioning approach that can be exploited as the
input of a dynamic resource management scheme. Using a Video on Demand use case
to justify our claims, we propose an analytical model inspired from standard
models developed for epidemiology spreading, to represent sudden and intense
workload variations. We show that the resulting model verifies a Large
Deviation Principle that statistically characterizes extreme rare events, such
as the ones produced by "buzz/flash crowd effects" that may cause workload
overflow in the VoD context. This analysis provides valuable insight on
expectable abnormal behaviors of systems. We exploit the information obtained
using the Large Deviation Principle for the proposed Video on Demand use-case
for defining policies (Service Level Agreements). We believe these policies for
elastic resource provisioning and usage may be of some interest to all
stakeholders in the emerging context of cloud networkingComment: IEICE Transactions on Communications (2012). arXiv admin note:
substantial text overlap with arXiv:1209.515
The state of peer-to-peer network simulators
Networking research often relies on simulation in order to test and evaluate new ideas. An important requirement of this process is that results must be reproducible so that other researchers can replicate, validate and extend existing work. We look at the landscape of simulators for research in peer-to-peer (P2P) networks by conducting a survey of a combined total of over 280 papers from before and after 2007 (the year of the last survey in this area), and comment on the large quantity of research using bespoke, closed-source simulators. We propose a set of criteria that P2P simulators should meet, and poll the P2P research community for their agreement. We aim to drive the community towards performing their experiments on simulators that allow for others to validate their results
Highly intensive data dissemination in complex networks
This paper presents a study on data dissemination in unstructured
Peer-to-Peer (P2P) network overlays. The absence of a structure in unstructured
overlays eases the network management, at the cost of non-optimal mechanisms to
spread messages in the network. Thus, dissemination schemes must be employed
that allow covering a large portion of the network with a high probability
(e.g.~gossip based approaches). We identify principal metrics, provide a
theoretical model and perform the assessment evaluation using a high
performance simulator that is based on a parallel and distributed architecture.
A main point of this study is that our simulation model considers
implementation technical details, such as the use of caching and Time To Live
(TTL) in message dissemination, that are usually neglected in simulations, due
to the additional overhead they cause. Outcomes confirm that these technical
details have an important influence on the performance of dissemination schemes
and that the studied schemes are quite effective to spread information in P2P
overlay networks, whatever their topology. Moreover, the practical usage of
such dissemination mechanisms requires a fine tuning of many parameters, the
choice between different network topologies and the assessment of behaviors
such as free riding. All this can be done only using efficient simulation tools
to support both the network design phase and, in some cases, at runtime
Self-Healing Protocols for Connectivity Maintenance in Unstructured Overlays
In this paper, we discuss on the use of self-organizing protocols to improve
the reliability of dynamic Peer-to-Peer (P2P) overlay networks. Two similar
approaches are studied, which are based on local knowledge of the nodes' 2nd
neighborhood. The first scheme is a simple protocol requiring interactions
among nodes and their direct neighbors. The second scheme adds a check on the
Edge Clustering Coefficient (ECC), a local measure that allows determining
edges connecting different clusters in the network. The performed simulation
assessment evaluates these protocols over uniform networks, clustered networks
and scale-free networks. Different failure modes are considered. Results
demonstrate the effectiveness of the proposal.Comment: The paper has been accepted to the journal Peer-to-Peer Networking
and Applications. The final publication is available at Springer via
http://dx.doi.org/10.1007/s12083-015-0384-
A Gossip-based optimistic replication for efficient delay-sensitive streaming using an interactive middleware support system
While sharing resources the efficiency is substantially degraded as a result
of the scarceness of availability of the requested resources in a multiclient
support manner. These resources are often aggravated by many factors like the
temporal constraints for availability or node flooding by the requested
replicated file chunks. Thus replicated file chunks should be efficiently
disseminated in order to enable resource availability on-demand by the mobile
users. This work considers a cross layered middleware support system for
efficient delay-sensitive streaming by using each device's connectivity and
social interactions in a cross layered manner. The collaborative streaming is
achieved through the epidemically replicated file chunk policy which uses a
transition-based approach of a chained model of an infectious disease with
susceptible, infected, recovered and death states. The Gossip-based stateful
model enforces the mobile nodes whether to host a file chunk or not or, when no
longer a chunk is needed, to purge it. The proposed model is thoroughly
evaluated through experimental simulation taking measures for the effective
throughput Eff as a function of the packet loss parameter in contrast with the
effectiveness of the replication Gossip-based policy.Comment: IEEE Systems Journal 201
SPAD: a distributed middleware architecture for QoS enhanced alternate path discovery
In the next generation Internet, the network will evolve from a plain communication medium into one that provides endless services to the users. These services will be composed of multiple cooperative distributed application elements. We name these services overlay applications. The cooperative application elements within an overlay application will build a dynamic communication mesh, namely an overlay association. The Quality of Service (QoS) perceived by the users of an overlay application greatly depends on the QoS experienced on the communication paths of the corresponding overlay association. In this paper, we present SPAD (Super-Peer Alternate path Discovery), a distributed middleware architecture that aims at providing enhanced QoS between end-points within an overlay association. To achieve this goal, SPAD provides a complete scheme to discover and utilize composite alternate end-to end paths with better QoS than the path given by the default IP routing mechanisms
Compositional gossip: a conceptual architecture for designing gossip-based applications
Most proposed gossip-based systems use an ad-hoc design. We observe a low degree of reutilization among this proposals. We present how this limits both the systematic development of gossip-based applications and the number of applications that can benefit from gossip-based construction. We posit that these reinvent-the-wheel approaches poses a significant barrier to the spread and usability of gossip protocols. This paper advocates a conceptual design framework based upon aggregating basic and predefined building blocks BD 2. We show how to compose building blocks within our framework to construct more complex blocks to be used in gossip-based applications. The concept is further depicted with two gossip-based applications described using our building blocks.(undefined
On Data Dissemination for Large-Scale Complex Critical Infrastructures
Middleware plays a key role for the achievement of the mission of future largescalecomplexcriticalinfrastructures, envisioned as federations of several heterogeneous systems over Internet. However, available approaches for datadissemination result still inadequate, since they are unable to scale and to jointly assure given QoS properties. In addition, the best-effort delivery strategy of Internet and the occurrence of node failures further exacerbate the correct and timely delivery of data, if the middleware is not equipped with means for tolerating such failures.
This paper presents a peer-to-peer approach for resilient and scalable datadissemination over large-scalecomplexcriticalinfrastructures. The approach is based on the adoption of epidemic dissemination algorithms between peer groups, combined with the semi-active replication of group leaders to tolerate failures and assure the resilient delivery of data, despite the increasing scale and heterogeneity of the federated system. The effectiveness of the approach is shown by means of extensive simulation experiments, based on Stochastic Activity Networks
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