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Published Articles >> Table of Contents >> Abstract
Second International Conference on the Quantitative Evaluation of Systems (QEST'05)
pp. 179-188
Workload Propagation - Overload in Bursty Servers
Qi Zhang, College of William and Mary Williamsburg, VA
Alma Riska, Seagate Research, PA
Erik Riedel, Seagate Research, Pittsburgh, P
Full Article Text:
 
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/QEST.2005.43
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| Abstract |
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Internet servers are developing into complex but central
components in the information infrastructure and are accessed
by an ever-increasing and diversified user population.
As such, they are susceptible to unpredicted and transient
overloads, making highly available, yet cost-effective
service a critical challenge. System responsiveness during
overload periods is at least as important as system behavior
under average, steady state load. Using measurements
from a 3-tier e-commerce server, we show how normal and
overload conditions propagate through the system hierarchy,
i.e., from the front-end server to the back-end database,
focusing on CPU, memory, and I/O performance. We find
that overload conditions at lower system levels occur not
only when the number of users in the system increases, but
also during rapid changes in the nature of the work requested
by the current users. These observation advocate
the development of system mechanisms at the lower levels
that can detect overload and self-adapt their configuration
parameters in order to ensure high service availability and
graceful performance degradation. We illustrate the effectiveness
of a scheduling mechanism at the disk and provide
a proof of concept that such self-adaptive scheduling mechanisms
at the lower levels are a step toward faster system
recovery under conditions of transient overload, and can
thus complement admission control at the front end.
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 Additional Information
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Index Terms- workload characterization, multi-tiered systems, overload conditions, TPC-W.
Citation:
Qi Zhang, Alma Riska, Erik Riedel,
"Workload Propagation - Overload in Bursty Servers,"
qest,
pp. 179-188,
Second International Conference on the Quantitative Evaluation of Systems (QEST'05),
2005
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