Title page for ETD etd-10242009-020057
|Type of Document
||Lee, Timothy J.
||Chitra93 :a Tool to Analyze System Behavior by Visualizing and Modeling Ensembles of Traces
||Master of Science
|No Advisors Found
|Date of Defense
A key cause of poor system performance is inherently due to the lack of understanding
of system behavior. Performance problems are especially apparent in parallel and distributed
programs, for which expected speedup is difficult to achieve. Theoretical models
and trace visualization tools are suitable for extracting insights into the behavior of a system.
Theoretical models available today work for certain types of systems and require possibly
unrealistic assumptions, and hence are not considered here. Existing trace visualization
tools have yielded new insights into the behavior of the sequential, parallel, and distributed
programs. However, they have two inherent limitations: (1) Each tool visualizes only one
execution of a program. (This is dangerous when analyzing concurrent programs, which are
prone to non-deterministic behavior.) (2) The applicable domain of a visualization tool will
be limited unless the tool incorporates a large variety of methods to visually display data.
This is because a single display method may yield new insights into only certain systems.
In addition, finding the "right" display that can provide the needed insights is a potentially
time-consuming process. This project carries through the previous work-CHITRA92. This
project addresses these limitations by providing the following four capabilities to analyze
traces: (1) CHITRA93 analyzes a set (or ensemble) of traces to obtain the typical behavior
of a system. (2) CHITRA93 incorporates three transforms to simplify ensembles by reducing
either the state space size or the interval over which time is defined in the ensemble. (3)
CHITRA93 builds compact summary of the dynamic behavior (or model) of a system from
an ensemble. (4) CHITRA93, to avoid building models that poorly fit an ensemble, provides
a suite of methods to partition ensembles into mutually exclusive, exhaustive, and homogeneous
subsets so that each subset displays "similar" behavior. These methods include
several visual techniques and statistical methods. Finally, a portion of the project seeks to
stabilize and to produce a correct version of CHITRA.
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