Resources Description, Selection, Reservation and Verification on a Large-scale Testbed

International audienceThe management of resources on testbeds, including their description, reservation and verification, is a challenging issue, especially on of large scale testbeds such as those used for research on High Performance Computing or Clouds. In this paper, we present the solution designed for the Grid'5000 testbed in order to: (1) provide users with an in-depth and machine-parsable description of the testbed's resources; (2) enable multi-criteria selection and reservation of resources using a HPC resource manager; (3) ensure that the description of the resources remains accurate

Provenance-Aware Sensor Data Storage

Sensor network data has both historical and realtime value. Making historical sensor data useful, in particular, requires storage, naming, and indexing. Sensor data presents new challenges in these areas. Such data is location-specific but also distributed; it is collected in a particular physical location and may be most useful there, but it has additional value when combined with other sensor data collections in a larger distributed system. Thus, arranging location-sensitive peer-to-peer storage is one challenge. Sensor data sets do not have obvious names, so naming them in a globally useful fashion is another challenge. The last challenge arises from the need to index these sensor data sets to make them searchable. The key to sensor data identity is provenance, the full history or lineage of the data. We show how provenance addresses the naming and indexing issues and then present a research agenda for constructing distributed, indexed repositories of sensor data.Engineering and Applied Science

The Virtual Network Scheduling Problem for Heterogeneous Network Emulation Testbeds

Network testbeds such as Emulab and the Open Network Laboratory use virtualization to enable users to define end user virtual networks within a shared substrate. This involves mapping users\u27 virtual network nodes onto distinct substrate components and mapping virtual network links onto substrate paths. The mappings guarantee that different users\u27 activities can not interfere with one another. The problem of mapping virtual networks onto a shared substrate is a variant of the general graph embedding problem, long known to be NP-hard. In this paper, we focus on a more general version of the problem that supports advance scheduling of virtual network mappings. We experimentally study the performance of heuristic testbed schedulers in the context of the Open Network Laboratory. Our algorithms incorporate Mixed Integer Programs to optimally solve key subproblems, are fast enough to respond to reservation requests in under one second, and rarely reject requests needlessly

Efficient range query processing in peer-to-peer systems

2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Doctor of Philosophy

dissertationNetwork emulation has become an indispensable tool for the conduct of research in networking and distributed systems. It offers more realism than simulation and more control and repeatability than experimentation on a live network. However, emulation testbeds face a number of challenges, most prominently realism and scale. Because emulation allows the creation of arbitrary networks exhibiting a wide range of conditions, there is no guarantee that emulated topologies reflect real networks; the burden of selecting parameters to create a realistic environment is on the experimenter. While there are a number of techniques for measuring the end-to-end properties of real networks, directly importing such properties into an emulation has been a challenge. Similarly, while there exist numerous models for creating realistic network topologies, the lack of addresses on these generated topologies has been a barrier to using them in emulators. Once an experimenter obtains a suitable topology, that topology must be mapped onto the physical resources of the testbed so that it can be instantiated. A number of restrictions make this an interesting problem: testbeds typically have heterogeneous hardware, scarce resources which must be conserved, and bottlenecks that must not be overused. User requests for particular types of nodes or links must also be met. In light of these constraints, the network testbed mapping problem is NP-hard. Though the complexity of the problem increases rapidly with the size of the experimenter's topology and the size of the physical network, the runtime of the mapper must not; long mapping times can hinder the usability of the testbed. This dissertation makes three contributions towards improving realism and scale in emulation testbeds. First, it meets the need for realistic network conditions by creating Flexlab, a hybrid environment that couples an emulation testbed with a live-network testbed, inheriting strengths from each. Second, it attends to the need for realistic topologies by presenting a set of algorithms for automatically annotating generated topologies with realistic IP addresses. Third, it presents a mapper, assign, that is capable of assigning experimenters' requested topologies to testbeds' physical resources in a manner that scales well enough to handle large environments

A Resource Publication and Discovery Framework and Broker-Based Architecture for Network Virtualization Environment

The Internet has received a phenomenal success over the past few decades. However, the increasing demands on the Internet usage and the rapid evolution of the applications and services provided over the Internet have demonstrated that the current Internet architecture is unsuitable for supporting many types of applications. Moreover, its ubiquity and multi-provider nature make nearly impossible the introduction of radical changes or improvements without coordination and consensus between many providers. Thus, any technological changes in the current Internet architecture could result in unintended consequences on the overall Internet usage. Network virtualization is considered as promising, yet challenging, solution to overcome these limitations. It commonly refers to the creation of several isolated logical networks that can coexist on the same shared physical network infrastructures. Its key concept is to enable several network architectures to run concurrently in a multi-role-oriented environment in which the role of the traditional Internet Service Provider (ISP) is decoupled into several roles such as infrastructure provider (InP), virtual network provider (VNP) and service provider (SP). Despite the promising benefits, this concept is associated with many challenges. These, among others, include the description and publication as well as discovery of resources on which virtual networks are deployed. In this thesis, we define a broker-based architecture that provides functions for publishing, discovering and negotiating as well as instantiating and managing resources in network virtualization environment. We proposed an information model that assists various providers in describing the resources and services they offer and we implemented a proof of concept prototype to demonstrate the feasibility of the proposed architecture. Moreover, we have conducted extensive experiments to evaluate the performance and the scalability of the implemented system

Distributed resource discovery on PlanetLab with SWORD

Large-scale distributed services such as content distribution networks, peer-to-peer storage, distributed games, and scientific applications, have recently received substantial interest from both researchers and industry. A