Computer Science Department
School of Computer Science, Carnegie Mellon University
PASTENSE: a Fast Start-up Algorithm for Scalable Video Libraries
Stavros Harizopoulos and Garth A. Gibson
Keywords: Video servers, scheduling, prefetching, start-up
latency, scalability, striping
Striping video clip data over many physical resources (typically disk drives
balances video server load with less data replication. Current striped video
delivery algorithms can have high start-up latency if the load is high.
We propose a new, fast start-up algorithm, PASTENSE. This algorithm
minimizes start-up latency by using aggressive prefetching to exploit
disk idle time, and using available RAM to dynamically optimize the
newly requested video's schedule. Our proposed method (a) does not
require changes in the existing striped data placement (b) it never
performs worse than alternate designs and (c) it achieves
significant benefits: up to 9 times faster start-up times for high loads.