(Georgia Institute of Technology, 1999)
Chervenak, Ann L.; Vellanki, Vivekanand; Yanasak, Ivan; Harel, Nissim; Rodenstein, Roy; Abowd, Gregory D.; Brotherton, Jason Alan; Ramachandran, Umakishore
We present a scalable workload model for media-enhanced classrooms.
Such classrooms include equipment for presenting multimedia streams
and for capturing streams of information (audio, video and notes)
during a lecture. Our model characterizes the workload of a
centralized or distributed server that supports multiple classrooms.
The workload includes server bandwidth, network bandwidth and server
storage requirements. Using our workload model, we present detailed
performance measurements of one media-enhanced classroom system,
Classroom 2000. We identify patterns in user behavior, and
demonstrate that the number of simultaneous study sessions varies with
time of day according to a beta distribution. In addition, we model
the total number of study sessions on a particular day using a simple
linear model that depends on proximity to midterm and final
examinations. Finally, we use the model to predict how the
capabilities of a Classroom 2000 server must scale to support hundreds
of classrooms and thousands of students.
(Georgia Institute of Technology, 1995)
Kazman, Rick; Abowd, Gregory D.; Bass, Leonard J.; Clements, Paul
Software architecture is one of the most important tools for designing and
understanding a system, whether that system is in preliminary design, active
deployment, or maintenance. Scenarios are important tools for exercising an
architecture in order to gain information about a system's fitness with
respect to a set of desired quality attributes. This paper presents a set of
experiential case studies illustrating the methodological use of scenarios
to gain architecture-level understanding and predictive insight into large,
real-world systems in various domains. A structured method for
scenario-based architectural analysis is presented, using scenarios to
analyze architectures with respect to achieving quality attributes. Finally,
lessons and morals are presented, drawn from the growing body of experience
in applying scenario-based architectural analysis techniques.