Summary: Adaptive Admission Control for Web Applications
with Variable Capacity
Vipul Mathur, Preetam Patil, Varsha Apte and Kannan M. Moudgalya
Indian Institute of Technology­Bombay
Powai, Mumbai, Maharashtra 400076, India
{vipulmathur,pvpatil,varsha,kannan}@iitb.ac.in
Abstract--The system capacity available to a multi-tier Web
based application is often a dynamic quantity. Most static
threshold-based overload control mechanisms are best suited
to situations where the system's capacity is constant or the
bottleneck resource is known. However, with varying capacity,
the admission control mechanism needs to adapt dynamically.
We propose and implement an adaptive admission control
mechanism that adjusts the admitted load to compensate for
changes in system capacity. The proposed solution is implemented
as a proxy server between clients and front-end Web servers.
The proxy monitors `black-box' performance metrics--response
time and rate of successfully completed requests (goodput). With
these measurements as indicators of system state, we employ a
control theory based feedback loop to dynamically determine the

Source: Apte, Varsha - Department of Computer Science and Engineering, Indian Institute of Technology Bombay

Collections: Computer Technologies and Information Sciences