This project focuses on the challenges
when designing a storage system suitable for realtime
video and audio retrieval. It is motivated by the Yima
continous media server project. The Yima server is based
on a cluster design. Each cluster node is an off-the-shelf
personal computer with attached storage devices, such
as magnetic disk drives. The research focuses on the
following aspects:
Online Scalability:
How do we scale the storage system incrementally while
(a) the system continues operation, (b) the minimal
amount of data is reorganized, and (c) the system continues
to be load balanced.
Heterogeneous Disk
Storage: How do we maximize the resource use of
disks with different data transfer rates and storage
sizes while at the same time ensuring that none of the
real-time constraints for audio and video data retrievals
are violated.
Research
Approach
SCADDAR: An Efficient Randomized
Technique to Reorganize Continuous Media Blocks
Scalable storage architectures
allow for the addition of disks to increase storage
capacity and/or bandwidth. This is an important requirement
for continuous media servers for two reasons. First,
multimedia objects are ever increasing in size, numbers
and bandwidth requirements. Second, magnetic disks are
continuously improving in capacity and transfer rate.
In its general form, disk scaling also refers to disk
removals when either capacity needs to be conserved
or old disk drives are retired. There are two basic
approaches to scatter the blocks of a continuous media
object on multiple disk drives: random and constrained
placement. Assuming random placement, our optimization
objective is to redistribute a minimum number of media
blocks after disk scaling. This objective should be
met under two restrictions. First, uniform distribution
and hence a balanced load should be ensured after redistribution.
Second, the redistributed blocks should be retrieved
at the normal mode of operation in one disk access and
through low complexity computation. We propose a technique
that meets the objective, while we prove that it also
satisfies both restrictions. The SCADDAR approach is
based on using a series of REMAP functions which can
derive the location of a new block using only its original
location as a basis. <
People
Roger Zimmermann
Research Assistant Professor at the USC Computer Science
Department
Email: rzimmerm@imsc.usc.edu
Phone: (213) 740-7654
Cyrus Shahabi
Assistant Professor at USC Computer Science Department
Email: cshahabi@cs.usc.edu
Phone: (213) 740-8162
Shu-Yuen Didi Yao
Research Assistant
Ph.D. Student
2001-02 Intel Foundation Graduate Fellowship Award Recipient
Email: didiyao@usc.edu
Phone: (213) 740-2289
Beomjoo Seo
Research Assistant
Ph.D. Student
Email: bseo@usc.edu
Phone: (213) 740-4177
This research is funded
in part by NSF grants EEC-9529152 (Integrated Media
Systems Center, an NSF Engineering Research Center)
and
IIS-0082826 (ITR grant)
Papers
SCADDAR: An Efficient
Randomized Technique to Reorganize Continuous Media
Blocks
Ashish Goel, Cyrus Shahabi, Shu-Yuen Didi Yao, and Roger
Zimmermann.
Proceedings of the 18th International Conference on
Data Engineering (ICDE
2002), San Jose,
California, February 26-March 1, 2002.
HERA: Heterogeneous Extension
of RAID
Roger Zimmermann and Shahram Ghandeharizadeh.
Proceedings of the 2000 International Conference on
Parallel and Distributed Processing Techniques and Applications
(PDPTA 2000), Las Vegas, Nevada, June 26-29, 2000.
Cyrus Shahabi,
Roger Zimmermann, Kun Fu and Shu-Yuen Didi Yao, Yima:
A Second Generation of Continuous Media Servers,
To appear in the IEEE Computer Magazine, 2002
Cyrus Shahabi,
Farnoush Banaei-Kashani, Decentralized Resource Management
for a Distributed Continuous Media Server, IEEE
Transactions on Parallel and Distributed Systems, Vol.
13, No. 6, June 2002
Cyrus Shahabi, Shahram Ghandeharizadeh,
Surajit Chaudhuri, On Scheduling Atomic and Composite
Multimedia Objects , IEEE Transactions on Knowledge
and Data Engineering, Vol. 14, No. 2, pages 447-455,
March/April 2002 EEE Transactions on Knowledge and Data
Engineering, Vol. 14, No. 2, pages 447-455, March/April
2002
Roger Zimmermann,
Kun Fu, Cyrus Shahabi, Didi Yao, Hong Zhu, Yima: Design
and Evaluation of a Streaming Media System for Residential
Broadband Services , VLDB 2001 Workshop on Databases
in Telecommunications (DBTel 2001), Rome, Italy , September
2001
