[ACM logo] 17th ACM Symposium on 
Operating Systems Principles

December 12-15, 1999
Kiawah Island Resort, near Charleston, SC, USA

Sponsored by
Association for Computing Machinery
Special Interest Group on Operating Systems

[Kiawah logo]

Poster session

A poster session was held on the evening of Monday 13th December. The posters was as follows, in no particular order:

Distributed shared memory for large computing clusters based on memory-mapped networks

Emmanuel CECCHET 
Ph. D. Student INPG/INRIA(*) - SIRAC Laboratory 
655, Avenue de l'Europe 
38330 Montbonnot Saint-Martin 

(*) INPG : Institut National Polytechnique de Grenoble 
    INRIA : Institut National de Recherche en Informatique et Automatique 
This research focuses on using new high bandwidth and low latency memory-mapped networks to build high performance cluster computing servers. The SIRAC laboratory has set up a cluster of PC interconnected by a Scalable Coherent Interface (SCI) network. We have developed a distributed shared memory (DSM) called SciFS, tightly integrated with the operating system, that tries to benefit from the high performances and the remote addressing capabilities of SCI. We briefly present our prototype then we discuss the SCI scalability issues by commenting on performance numbers for different network architectures. Finally we introduce the new hardware and software problems for large SCI clusters.

PASIS: Perpetually Available and Secure Information Systems

Han Kiliccote
Institute for Complex Engineered Systems
Carnegie Mellon University
5000 Forbes Avenue
Carnegie Mellon University
Pittsburgh, PA 15213
PASIS is an innovative framework for demonstrating perpetually available information systems that guarantee the survivability of information under malicious attacks or system component failures. PASIS is based on a novel architecture which breaks all information into "chunks" and distributes these "information chunks" in novel ways by using information replication and dispersal methods. This enables PASIS to not have any single point of failure (i.e., it is not possible to destroy the information in PASIS or to degrade the performance, by eliminating or capturing few selected components or information chunks within the system) and thereby achieve a very high degree of security and resiliency against failures and attacks.

Tuplink: a communication system for PDAs and micro-devices

Yasushi Negishi
IBM Research, Tokyo Laboratory
1623-14, Shimotsuruma, Yamato-shi, Kanagawa-ken, 242-8502, Japan
negishi@trl.ibm.com (or negishi@jp.ibm.com)
Tuplink is a communication system for supporting requirements of communication systems for PDAs and micro-devices, those are to support operations while the link is disconnected, to work with limited memory and to use low quality links causing accidental packet loss and sudden disconnection. Tuplink is a Linda-based system, and supports one-to-one communication. Two pools are placed at both ends of communication path. Linda operations are used for handling each of local pool, and "sync" operation is introduced to synchronize the contents of the two pools. We also explain Tuplink protocol and a sample application using Tuplink, called "microNotes". MicroNotes is a commercial software supporting subset of Lotus Notes functions. Demonstration of microNotes is also shown.

RENS: a framework for Rapidly Evolvable Network Services

Anurag Acharya, Maximilian Ibel, Matthias Koelsch, and Michael Schmitt
Department of Computer Science
UC Santa Barbara
Santa Barbara, CA 93106
The demand for net-based services continues to expand. Writing such services remains hard as each such service usually needs to provide fault tolerance, service discovery, and scalability. Typically, this functionality is implemented from scratch for every service. There is, however, significant commonality between the requirements for large class of services. The goal of the RENS project is to provide this common functionality in a runtime environment, thus freeing service designers to focus on service-specific code. RENS services consist of distributed components connected by named communication channels. The communication structure of RENS services is specified explicitly, and components are programmed in an event-driven manner, having only knowledge of local state. The RENS runtime environment leverages its knowledge of the communication structure to provide automatic instantiation of distributed services, detection of and transparent recovery from common faults, and scaling on demand. A RENS prototype is currently operational and has been used to develop a suite of distributed services including location dependent information servers, customcast, selectcast, anycast, chat servers, a hierarchical streaming audio network and caching proxies for intermittently connected devices.

Distributed, flexible memory management in an operating system supporting quality of service

Ian McDonald
Department of Computing Science
University of Glasgow
17 Lilybank Gardens
G12 8QQ
Ongoing work is presented that takes advantage of several key trends in computing science to provide a novel, flexible, extensible, distributed, user-level virtual memory management hierarchy offering quality of service (QoS) to applications. The new hierarchy incorporates compressed caching, disk pre-fetching and remote paging to provide a flexible environment that allows application developers to finely tune their run-time environment. An initial implementation of this new hierarchy has been built, with future work focusing on providing a high level QoS interface.

The INSTANCE project: operating system enhancements to support multimedia servers

Paal Halvorsen, Thomas Plagemann, Vera Goebel
UniK - Center for Technology at Kjeller, 
University of Oslo,
Postbox 70, N-2027 Kjeller
Traditional operating systems do not provide adequate support for a multimedia-on-demand server supporting video and audio playout to a large amount of users. The objective of the INSTANCE project is to identify and eliminate possible bottlenecks of traditional operating systems by improving the design of traditional server based systems. So far, we have come up with three possible orthogonal system improvements: network level framing, integrated error management and a zero-copy-one-copy memory architecture. In this poster, we present the basic ideas of our system improvements.

Restricted delegation: seamlessly spanning administrative domains

Jon Howell and David Kotz
Dartmouth College
6211 Sudikoff Lab
Hanover, NH  03755
Restricted delegation allows transitive sharing, a requirement for sharing that spans administrative boundaries. Each principal in a chain of delegation can restrict what is shared with the next, so that each principal can act both as a user (recipient) and administrator (giver) of any resource. A logic and formal semantics helps us intuitively grasp the consequences of a security model. They justify the decision procedure that ends up in the implementation, and they can confirm or reject the soundness of proposed extensions. Our logic and semantics adds restricted delegation to the calculus for access control while preserving first-class conjunct and quoting principals.

A Unix-like personality supporting Quality of Service

Rolf Neugebauer
Department of Computing Science
University of Glasgow
Glasgow, G12 8QQ, Scotland, U.K
This poster presents a Unix-like run-time environment for the Nemesis operating system. Its aim is to provide Nemesis' advanced resource management mechanisms to existing Unix applications with no or few source code changes. In this poster we describe the overall design goals and then focus on some interesting aspects of their implementation.

A scalable and extensible cluster-based router architecture

Prashant Pradhan, Tzi-cker Chiueh
Experimental Computer Systems Lab
Dept. of Computer Science
SUNY at Stony Brook
Stony Brook, NY-11794-4400
Increasing demand for network bandwidth and growing need for richer functionality within the network, have given rise to conflicting requirements for network router design. Edge routers, in particular, are faced with the challenge of maintaining high-speed forwarding performance, as well as providing versatile functionality. Suez is a scalable cluster-based architecture designed to provide high raw packet forwarding performance and flexible protocol processing extensibility at edge routers. The implementation of the Suez architecture consists of two major components:
  1. An efficient data path that utilizes programmable network interfaces to forward data efficiently : both between interfaces, as well as between interfaces and the router's queues.
  2. A dataflow-based computation model, which uses protection hardware of general-purpose processors to provide safe, efficient, and flexible extensibility.

Automatic generation of I/O prefetching hints through speculative execution

Fay Chang and Garth Gibson
School of Computer Science
Carnegie Mellon University
5000 Forbes Avenue
Pittsburgh, PA 15213 
Aggressive prefetching is an effective technique for improving the performance of disk-bound applications. However, it requires timely and accurate knowledge of the future data needs of applications. We propose that applications can discover their own future data needs by exploiting unused processing cycles during I/O stalls to speculatively pre-execute their code. We find that a naive design for transforming application binaries to perform speculative execution obtains significant performance benefits in many cases, but falls short of the benefits of manually modifying applications to provide prefetching information. Early experiments show that we can enhance the effectiveness of our approach by combining static and dynamic techniques to make speculation self-aware.

Automatic function placement in distributed storage systems

Khalil Amiri, David Petrou, Greg Ganger, Garth Gibson
Carnegie Mellon University
5000 Forbes Avenue
Pittsburgh, PA 15213 
Traditional distributed filesystems and applications statically partition their functions between client and server machines. Dynamic changes in workload and system characteristics often make this design-time function placement suboptimal. Our prototype system, ABACUS, improves performance and manageability by automatically migrating application (e.g., search) and filesystem function (e.g., caching, RAID, directory service) among cluster nodes at run-time. Our initial experiments show that dynamic placement results in significant benefits in response time, often outperforming the best possible static placement and requiring only black-box monitoring of functional modules (objects) and of the resources available throughout the cluster.

Persistent distributed data structures to simply cluster-based internet services

Steven D. Gribble, Eric A. Brewer, David Culler, and 
Joseph M. Hellerstein
UC Berkeley CS Division
445 Soda Hall #1776
UC Berkeley Campus, Berkeley, CA 94720-1776
In this work, we propose a new abstraction for persistent data management on clusters of workstations: "distributed data structures", or DDS. A DDS is a scalable, self-managing repository for persistent, consistent, highly-available data that exports a data-structure interface (such as a hash table, log, or tree). A DDS decouples consistency and persistence from service logic, simplifying service construction. The poster discusses the design and implementation of a hash-table DDS, including the use of asynchronous state-machine driven I/O, and describes two example services and future directions.

Differentiated QoS through quality aware transformation of web content

Surendar Chandra, Carla Schlatter Ellis, Amin Vahdat
Department of Computer Science, Duke University,
PO Box 90129
Department of Computer Science, Duke University,
Durham, NC 27708-0129
This poster addresses ongoing work on a web server that manages its consumed resources and provides differentiated Quality of Service (QoS) using a quality-aware image transcoding. The key insight behind our work is that allocation of critical resources can be done dynamically at the application level in response to client access patterns using informed transcoding techniques with well understood tradeoff characteristics. These techniques enable us to control and allocate the system resources to the various client classes (in a loaded web server). We use informed transcoding techniques to provide different variations of the same multimedia object. Preliminary results are encouraging; we can not only manage the total consumed resources but also provide differentiated QoS. Our system also avoids unnecessary transcoding operations and unproductive decreases in content quality.

The Sombrero distributed single address space operating system

Donald Miller and Alan Skousen
Computer Science and Engineering Department
Arizona State University
Tempe, AZ 85287-5406
The Sombrero operating system project is an experiment to investigate the potential of a distributed large Single Address Space Operating System (SASOS) as a computing environment. We are currently prototyping Sombrero on Alpha 21164 based NT systems. The prototype gives NT the ability to manage 8-terabyte data sets across a network in a single distributed address space. This distributed address space supports a mechanism that allows multiple network users to have access to and a consistent view of the same addresses while at the same time being protected from one another's activities. We also propose changes to current stock processor architecture to facilitate the single large distributed address space design. Sombrero provides a flat networkwide peer level architecture for user and system programs. Sombrero makes use of its hardware support for object grained protection, separate thread related protection domains and implicit protection domain crossing to provide support for modern distributed computing that is not available from SASOSs built on stock processors.

FiST: a language for stackable file systems

Erez Zadok and Jason Nieh
Computer Science Department
Columbia University, Mail Code 0401
1214 Amsterdam Avenue
New York, NY 10027
We propose a new language, FiST, to describe stackable file systems. FiST uses operations common to file system interfaces. From a single description, FiST's compiler produces file system modules for multiple platforms. The generated code handles many kernel details, freeing developers to concentrate on the main issues of their file systems. We built several file systems using FiST on Solaris, FreeBSD, and Linux. Our experiences with these examples shows the following benefits of FiST: development time is reduced more than ten times; average code size is reduced 5--36 times; minimal performance overhead of stacking is less than 4%.

High-performance cluster-based Internet servers

Eric Jul, Povl Koch, Jørgen S. Hansen, Michael Svendsen, Kim
Henriksen, Kenn Nielsen, and Mads Dydensborg
Department of Computer Science
University of Copenhagen
Universitetsparken 1
DK-2100 Copenhagen
The goal of this project is to combine the theory of DSM systems with database technology to build a distributed database solution that can be used by search engines and E-commerce systems where access latency and availability are important and where updates to data should be reflected in the system as soon as possible. This project focus is on centralised cluster-based Internet servers with very large data sets -- normally Tera bytes of data. The system uses the SCI technology as communication backbone, a technology that allows nodes to map memory regions of other nodes into their local address space. The SCI network handles consistency of the memory regions on the nodes.

Integrating virtual memory with user-level network communication

Joon Suan Ong, Yvonne Coady and Michael J. Feeley
University of British Columbia
2366 Main Mall,
University of British Columbia,
Vancouver, B.C. V6T 1Z4,
Communication systems use zero-copy protocols and user-level networking to improve performance. They require explicit page pinning and address translation for the NI to access user-pages. By exploiting spatial locality, statically pre-pinning and lazily unpinning pages can amortize the cost of dynamic pinning. However, this leads to poor memory utilization and expensive system calls. We propose modifying the VM system to provide the NI with translation information. The NI controls pinning for DMA operations. The VM system can still exercise its MM policies over those pages.

Original call for posters

We have room for about 16 positions, each with up to two posters, and we are aiming to fill every available slot. (Physically, a "poster" is a portrait format sheet of paper, mountable on foam-core, probably 32" * 40" in size.)

The selection process will aim to pick topics that look like they will be of interest to the attendees, and generate lively discussions.

A poster is an ideal way to present your ongoing work in a more structured manner than a work-in-progress talk, yet one that makes for easy interaction and discussion. You might consider providing an overview of some of your recent work, or describing one aspect in more detail, or use it to get feedback on work you are thinking about starting.

To obtain a poster-session slot, please:

  1. Develop one or two posters in sketch/outline form, plus up to 2 pages of "speaker notes" to accompany them. The ideal would be to end up with a "thumbnail" for each of your posters, each one occupying a page, together with the text you would give to somebody else so they could represent you at the poster session.

  2. Put these into a single Adobe PDF file that contains no more than four 8.5" x 11" pages.

  3. Construct a single piece of email, as follows:
    1. The main body of the email (not an attachment!) should be a cover letter, that provides:
      • contact info, such as phone number, email, address;
      • your name(s) and affiliation(s), as you would like them listed in a program;
      • the title of the poster;
      • whether you'd like want one or two easels (posters);
      • a single-paragraph abstract, no more than 10 lines long;
      • anything else that it will be vital for us to know.
    2. A single MIME-encoded attachment containing the Adobe PDF file you constructed above.

  4. Email the result to: sosp99posters@tesla.hpl.hp.com, to arrive by 4pm Pacific Standard Time on Wednesday November 17th, 1999. Please don't use this email address for correspondence - the mailbox will probably not even be looked at until the deadline! If you do have questions, please write directly to the program chair wilkes@hpl.hp.com
If your poster is accepted, you will be notified by November 22nd, and provided with additional details on how to format/prepare your posters. For example, we will provide easels and board to mount the poster on.

Your poster will be listed on the conference web site, and you'll be given the chance to provide an extended abstract (or pointer to one) for the web site, too, if you wish.

Last modified: Mon Dec 20 11:51:09 MET 1999