Seminars
SPECIAL SEMINAR FEATURING LEADING RESEARCHERS IN THE
COMPUTER SYSTEMS COMMUNITY


DATE:
Thursday, August 25, 200
5
TIME: 11:30 am - 4:30 pm

PLACE: CIC 2101


SPEAKERS:

11:30 am
Richard Golding, IBM Almaden
Zygaria: Storage Performance as a Managed Resource
SLIDES - pdf [83K]
12:45 pm
Jon Howell, Microsoft Research
From Spec To Code: Formal Specification and Systems
2:00 pm
Rodney Van Meter, Keio University, Japan
Quantum Computing *Systems*: State of the Art, Summer 2005
SLIDES - pdf [1.5M]
3:15 pm
Jason Flinn, University of Michigan, Ann Arbor
Speculative Execution in a Distributed File System

 


SEMINAR ANNOUNCEMENTS:


SPEAKER: Richard Golding, IBM Almaden
Zygaria: Storage Performance as a Managed Resource
The Kybos project at IBM Almaden is building a scalable, self-managing storage system. The storage system can move data as necessary to meet changing resource needs. As part of this, we have designed a hierarchical I/O scheduling algorithm to manage the consumption of performance resources, and implemented it in a device driver called Zygaria. This algorithm ensures that applications receive specified throughput levels and are throttled when they go over specified limits. The algorithm also ensures that remaining performance resources are distributed in what we call water-level fair sharing. In this talk I will give an overview of the hierarchical token bucket scheme used in Zygaria, initial performance results, and discuss how we have improved its performance.

BIO: Dr. Golding is on the research staff at IBM Almaden Research Center, where he leads the Collective Intelligent Bricks software project. Before that he was an architect at Panasas, working on a distributed object storage product, and he spent several years in the Storage Systems program at Hewlett-Packard Labs, working on projects such as AutoRAID and self-managing storage.

^TOP


SPEAKER: Jon Howell, Microsoft Research
From Spec To Code: Formal Specification and Systems
Systems builders often dismiss "formal" tools as only useful in ivory towers. We used some formal specification techniques to tackle a subtle distributed file system design problem. We found some techniques very valuable, and others less so.

The intended audience consists of systems builders that can benefit from having new tools in their systems-building toolboxes. I will share our experience using these tools to rapidly prototype distributed system design problems, and our experience moving rapidly from a formal design to a robust implementation.

BIO: Jon Howell is a researcher in the Systems and Networking group at Microsoft Research. He has been mainly involved in the FARSITE serverless distributed file system project. His thesis at Dartmouth College focused on distributed naming and security.

^TOP


SPEAKER: Rodney Van Meter, Keio University, Japan
Quantum Computing *Systems*: State of the Art, Summer 2005
In this talk, I will review recent progress in quantum computing *systems*. I will start with an extremely brief review of the principles and power of quantum computing, describe a taxonomy of quantum computing technologies from a systems point of view, then move into recent results in ion trapping, all-optical quantum computing, and error management (including quantum error correction, fault tolerance, and gate accuracy). This will allow me to place my own research on a quantum multicomputer and quantum arithmetic in context. I will finish with a list of what I consider to be the most important open problems to be attacked as we progress toward the realization of useful quantum computers.

BIO: Rod Van Meter has almost two decades of broad-ranging experience in computer systems, specializing in the intersection of networks and storage systems for most of the last decade. He has worked at both companies and research institutions in the U.S. and Japan, including USC/ISI, Quantum (the hard disk maker), and Nokia. In conjunction with his current interest in quantum computing, he has taken on the role of doctoral candidate at Keio University.

^TOP


SPEAKER: Jason Flinn, University of Michigan, Ann Arbor
Speculative Execution in a Distributed File System
This talk will describe a system called Speculator that improves the performance of distributed file systems by supporting speculative execution within the Linux kernel. Speculator allows multiple processes to share speculative state by tracking causal dependencies propagated through inter-process communication. It guarantees correct execution by preventing speculative processes from externalizing output, e.g., sending a network message or writing to the screen, until the speculations on which that output depends have proven to be correct. Speculator improves the performance of distributed file systems by masking I/O latency and increasing I/O throughput. Rather than block during a remote operation, a file system predicts the operation's result, then uses Speculator to checkpoint the state of the calling process and speculatively continue its execution based on the predicted result. If the prediction is correct, the checkpoint is discarded; if it is incorrect, the calling process is restored to the checkpoint, and the operation is retried. We have modified the client, server, and network protocol of two distributed file systems to use Speculator. For PostMark and Andrew-style benchmarks, speculative execution results in a factor of 2 performance improvement for NFS over local-area networks and an order of magnitude improvement over wide-area networks. For the same benchmarks, Speculator enables the Blue File System to provide the consistency of single-copy file semantics and the safety of synchronous I/O, yet still outperform current distributed file systems with weaker consistency and safety.

BIO: Jason Flinn is an assistant professor in the Electrical Engineering and Computer Science department at the University of Michigan, Ann Arbor. His research interests include mobile computing, file systems, and operating systems.

^TOP


Visitor Coordinator: Angela Miller, amiller@cs.cmu.edu, 8-6645

For Further Seminar Info Contact:
or visit http://www.pdl.cmu.edu/SDI/