Peter Druschel - US grants

This project will design, implement and experiment with an operating system that satisfies the requirements of emerging applications such as multimedia, parallel computing, and distributed information retrieval. These performance critical applications can be characterized by their intense use of communication, and by their need for tight control of the machine's resources. Existing operating systems often limit the performance of such applications, thereby preventing users from reaping the power of high-performance computer systems. As a result, lagging operating system technology threatens to delay the acceptance of parallel computing, multimedia, and other services in the emerging national information infrastructure. The major themes of the project are (1) designing OS communications support that delivers performance close to that provided by the network; (2) achieving OS performance that scales with the underlying computer system's performance; and, (3) investigating open service implementations that allow customization of OS services to match precisely an application's requirements. The goal is to deliver the resources provided by high-performance computer systems to applications, without sacrificing functionality, fairness, safety, and portability. Methods include the re-evaluation of current operating systems in light of changing application requirements and hardware performance characteristics; design, implementation, and experimentation with appropriate solutions; and, dissemination of results through publication and distpibution of software artifacts. Education plans of this CAREER project include the development of an interactive teaching style, introduction of a hands-on course in parallel programming using networks of workstations, and the organization of a summer program designed to expose junior high students to computer and information technology.

9713032 Rice University R. Cartwright CISE Educational Innovation: Exploring A Safe Approach to Software Engineering This CISE Educational Innovation award supports the development of a new undergraduate course sequence in software engineering that focuses on emerging principles of program design and validation applicable to type-safe languages. These courses are built on the high-level design principles incorporated in the new introductory programming sequence at Rice and draw on recent research in algorithmic verification through soft typing and modular program composition. Two courses, targeted at upper-level undergraduates, are being developed. The first course is a foundations course using safe languages that focuses on the principles of program and module design, verification, debugging, and performance tuning and the second is an interdisciplinary studio course that applies the principles of the foundations course to writing innovative networking software. These courses have the potential to make major impact on course work in software engineering in the future.

This project develops a novel architecture for the construction of scalable Internet servers from commodity hardware and modular application software components. The architecture targets network servers based on clusters of workstations or PCs, and allows servers to fully realize the performance potential of this platform. Off-the-shelf server applications are executing on the server nodes in a modular fashion and are unaware of the existence of multiple server nodes. As a result, ScalaServer leverages both existing server applications and the price/performance curve of commodity hardware. The design of the ScalaServer architecture will be based on the results of extensive tracedriven simulations. Prototype systems for both single-node and cluster servers will be disseminated to the research community. It is expected that the project will significantly advance the state-of-the-art in highperformance, scalable, and cost-effective network server design and implementation, an area that is critical to the future global information infrastructure. The project will also contribute to the education of scientists and engineers in this important area, both at the graduate and undergraduate level.***

Abstract:

In a battery-powered sensor network, energy and communication bandwidth are both limited. Moreover, processing a sensor measurement locally often requires orders of magnitude less energy than communicating it to a distant node, yielding an interesting communication/computation tradeoff: whenever possible, the network should reduce the need for global communication at the expense of increased local processing and communication. A promising approach for reducing global communication is to perform signal processing to extract key information inside the sensor network in a distributed fashion, thus dramatically reducing global communication requirements without losing fidelity.

This project aims to develop a sensor network architecture whose communications hierarchy is aligned with the information flow of its computations. In particular, the research involves developing (1) a multi-overlay sensor network architecture that supports both multi-scale and proximity communication and computation; (2) new multiscale sensor data representations based on wavelet transforms; and (3) network services for sychronization and localization of network nodes. The research includes analysis, simulation, and a small-scale testbed of sensor nodes on the Rice University campus.

Within little more than a decade, digital information and the Internet have assumed a critical role in virtually all sectors of society, including education, commerce, science, government, and entertainment. However, today's Internet is dependent on wired or cellular wireless infrastructure. This dependence limits the reach of digital communication to regions of the world where the required infrastructure is technically and economically feasible; at the same time, it renders the network vulnerable to disasters and attacks that threaten this fixed infrastructure. This proposal aims to develop technologies to reduce the dependence of digital communication on wired and cellular wireless infrastructure, thus extending its reach into underdeveloped parts of the world and economically disadvantaged part of society and increasing its resilience to natural disasters, acts of war, or terror attacks on its physical infrastructure.
The work exploits synergies between two areas of research that have enjoyed dramatic advances in recent years, but have to date mostly worked independently: (1) ad hoc networking, and (2) decentralized, self-organizing distributed systems. They have assembled a team of experts in each of these areas that will jointly tackle the major technical challenges towards a network architecture that exploits infrastructure when it is available but does not depend on it:
Self-organizing network hierarchy: Will develop a novel, self-organizing buoy protocol that recursively subdivides the network into an adaptive, proximity-based hierarchy of cells. The cell hierarchy provides the foundation for scalable routing and provides a low-overhead, proximity-based overlay structure that can be used to support network services. Periodic broadcasts from buoy nodes in each cell efficiently disseminate aggregated location, addressing, and routing information. Scalable ad hoc network routing: Based on the buoy protocol, they will develop an ad hoc network routing architecture for mobile and stationary devices that scales to at least tens of thousands of nodes. Nodes maintain only a small amount of routing state that is logarithmic in the size of the network, in exchange for a slightly longer route length. Nodes maintain their routing state passively by listening to buoy broadcasts, which results in very low routing overhead. The per-node space and message requirements of the protocol grow at most logarithmically with the size of the network.
Self-organizing network services: The proposers plan to develop self-organizing, robust, and secure network services that exploit the hierarchical overlay structure of the buoy protocol. Basic naming, host configuration and network time services will ensure the operation of the network in the absence of fixed infrastructure servers that provide conventional DNS, DHCP and NTP services. Other self-organizing services will provide email, instant messaging, storage, and content distribution in the absence of a server infrastructure, manual administration, high-capacity backbones or trusted entities. Our approach builds on foundations from p2p systems, but takes advantage of the hierarchical, proximity-based low overhead overlay structure provided by the buoy protocol to provide a solution suitable for ad hoc wireless environments.
Integrated ad hoc network architecture: The proposers plan to develop a network architecture that will integrate wired and wire-less networks, infrastructure-based, and self-organizing services. The architecture takes advantage of existing infrastructure when and where available, without depending on its presence. In the wake of a disaster, the architecture will allow remaining islands of surviving infrastructure to self-organize jointly with wireless, mobile components to recover and resume connectivity and emergency network services. Similarly, the architecture will allow the integration of islands of wired infrastructure via wireless ad hoc communication in developing countries.
The intellectual merits of this work include the development of the science and technology to meet these challenges; they will evaluate theoretical results, algorithms and protocols through analysis, simulation, and experimental evaluation of prototype implementations; disseminate the results via publications, industrial collaborations, and student training; and to distribute software artifacts for evaluation and use by industry and the research community.
The broader impacts of this work include the development of technologies that will substantially increase the
resilience of digital networks to physical disasters or attacks and that will extend its reach into economically disadvantaged parts of society and underdeveloped parts of the world. Educational impacts include the training of students and research personnel and outreach to educational institutions not historically involved in research.

CNS-0509297 CSR/PDOS: Security and Incentives for Overlay Network
Infrastructure
Abstract: Proposed Research
Overlay network systems have largely been engineered to operate in a world where every
node cooperatively executes the protocol as specified. Nodes either operate correctly, or
cease to work altogether (i.e., fail-stop). This model is quite successful when nodes
can trust one another, but this limits overlay systems from operating in the more general
case when they might be operating on untrusted, end-user computers. Such users will be
economically rational, meaning they will seek to get as much benefit from the network as
possible while contributing as little of their own resources. Our research will examine
extensions to these systems where nodes perform accounting, allowing them to track
which nodes are and are not performing correctly, making it possible to offer preferential
service to nodes that offer preferential service in return. These and other related
techniques will ultimately result in incentives-compatible designs that enable a new
generation of peer-to-peer applications, including distributed backup systems, distributed
file systems, and distributed email systems. Our work will be disseminated as part of the
FreePastry project, which provides a high-quality and scalable implementation of a
variety of overlay network services and is available under a BSD-style license. Likewise,
our work will become part of the next-generation Tor anonymous communication system.

This project aims to develop an adaptive sensor network architecture that enables the efficient, large-scale, long-term, low-cost, on-demand monitoring of a variety of physical phenomena with high fidelity. The core theme is that distributed signal processing and data assimilation of sensor data, as well as network management and monitoring, should be performed inside the sensor network in order to reduce energy consumption and global communication needs, leading to dramatically increased sensor lifetimes and much higher fidelity in the tracking of the physical phenomena of interest. The goal is to develop a flexible, self-monitoring architecture for this type of in-network processing and sensor networking that exploits adaptivity to significantly improve the network's efficiency, robustness, and usefulness. Two kinds of adaptivity are considered: (1) data adaptivity, where the network topology is adapted to align communications with the natural data flows; and (2) resource adaptivity, where the network topology is adapted based on computational, battery, or bandwidth resources. The expected results include the development of adaptive communication protocols and routing topology, the development of network management tools for sensor communication performance monitoring and inference, and for sensor distribution monitoring, as well as the experimental deployment of the adaptive sensor network architecture in a small-scale testbed of sensor nodes on the Rice University campus. Results will be disseminated through technical reports posted on the project web page, through papers presented at professional meetings, as well as through journal publications.