Download Scalable Multimedia Servers - Computer Science

Scalable Multimedia Servers
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Walid G. Aref
Research Scientist
Panasonic Information and Networking Technologies
Laboratory (PINTL)
Princeton, New Jersey
Starting Fall ‘99: Associate Professor
Department of Computer Sciences
Purdue University
Characteristics of Multimedia Data
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Large number of objects
Large object sizes
Very high dimensionality
Retrieval by content
• similar by not exactly the same
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Real-time constraints
Spatial and temporal dependencies
• e.g., as in video data
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Target Features of a Multimedia
Server
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Support for a variety of multimedia
types and formats
 Real-time guarantees
 Scalable
 Reliable
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Client/Server Multimedia System
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Centralized server
Uses the server
host to perform all
of file system
functions
Storage elements
behind the server
Server becomes
bottleneck with
increasing users
Server
High Speed
Network
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Scalability of a Multimedia Server
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Scale up with increasing user pool
 Should not involve centralized entity
 Distribute work among participating
entities
 Provide real-timeliness
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Disks Attached to Network
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Server
High Speed
Network
Autonomous
Disk
Autonomous
Disk
High Speed
Network
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Architecture for Distributed
Multimedia Server
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Autonomous Disks
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2
3
4
5
N
Configuration
Manager
High Speed Network
User Setup
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Architecture of Autonomous Disk
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Network-Attached Storage Device
• NASD
Processor
Memory
Controller
Storage
Network
Interface
Card
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Functionality of a NASD
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Light-weight
processing
and scheduling
•Disk request scheduling
•Network transmission
•Access security check
•Protocol processing
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Volume Organization
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Autonomous
attribute disk
• Volume with non-intersecting and homogeneous disks
A
D
D
A
• Volume with non-intersecting and non-homogeneous disks
Autonomous
data disk
D
A
D
D
D
D
D
• Volume with intersecting and homogeneous/non-homogeneous disks
A
D
D
D
D
D
D
A
D
Higher capacity
higher bandwidth disk
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Design Issues
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Multimedia data striping
 Volume management
 Free list management
 Concurrency control issues
 Directory management
 Access Security issues
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Scheduling of NASD Devices
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Resources with conflicting
requirements
•Disk Scheduling
•Network Scheduling
•User Requests with Real-time Deadlines
•User Priorities
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Multi-dimensional scheduling problem
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Reliability
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Storage Level Fault Tolerance
• Hardware RAID
• Software mirroring
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Network Level Fault Tolerance
• Redundant network and interfaces
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Real-Timeliness
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Admission control
Bandwidth Enforcer
Application
API
Assurance of
real-timeliness
Bandwidth
Enforcer
DFS kernel
Network
Client Host
Memory
Network
and Disk
Scheduler
Network
Interface
Card
Storage
Admission
Controller
Processor
Autonomous Disk
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Multimedia Traffic Characterization
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Video data
• variable-bit rate (VBR)
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Self-similarity
Long-range dependency
Effect of data striping
More appropriate bandwidth
enforcement algorithms
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Data Mining in Multimedia
Databases
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• surveillance applications (video data)
• remote sensing
• patient monitoring (video & time sequence data)
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Huge amounts of data
Hard for human to make use of it
Target: Automatically detect
regular/irregular patterns/sequences
Needs large-scale multimedia
infrastructure
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Courses in Multimedia Databases
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Fall ‘99: CS690D - Advanced Topics in
Multimedia Databases
• Design and prototyping of serverless
distributed multimedia systems
• Scheduling in network-attached storage
devices
• Data mining in video databases
• Retrieval by content and multimedia
indexing
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Courses in Multimedia Databases
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Spring ‘2000: CS541 - Advanced
Database Systems
• Disk scheduling with real-time contraints
• Incremental and online data mining
algorithms
• Generalized indexes (GiST) and their
applications in multimedia databases
• Retrieval by content and multimedia
indexing
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