POLUS: A self-evolving model-based approach for automating the observe-analyze-act loop | Posted on:2006-03-08 | Degree:Ph.D | Type:Thesis | University:University of Illinois at Urbana-Champaign | Candidate:Uttamchandani, Sandeep | Full Text:PDF | GTID:2458390008971920 | Subject:Computer Science | Abstract/Summary: | | Computer systems today are managed by human administrators who are required to continuously observe the system, analyze its behavior, and activate corrective actions (generally referred to as the Observe-Analyze-Act loop). Automating the OAA loop within real-world systems is a non-trivial problem, but the growing economic incentive associated with making systems self-managing; and significant increase in the computation bandwidth have made OAA automation a promising area of research. The existing choices for OAA automation can be characterized as one of the following: policy-based, feedback-based, empirical or learning based, and model-based---the available solutions suffer from complexity, brittleness, slow convergence, and have been useful to automate only trivial management scenarios.; This thesis proposes POLUS: a methodology for OAA automation using a model-based approach with integrated learning and feedback . POLUS uses models of system behavior for deciding the corrective action to be invoked---it continuously refines models using monitor data, exhaustively searches for an optimal corrective action using constrained optimization, and executes the selected action using a variably aggressive feedback loop. The core architecture of POLUS closely resembles that of an Expert System: A Knowledge-base of models for components, workloads, actions, and a Reasoning engine that selects and executes a "feasible" action at run-time.; The details of the POLUS methodology consist of: Representation of domain-specific details as models; creation and evolution of these models in an automated fashion; decision-making for the corrective action(s) to be invoked at run-time; handling divergent system behavior during action execution. POLUS is the first-of-a-kind in using a model-based approach for OAA automation; by applying the following operational principles. P OLUS addresses challenges related to model inaccuracies in real-world systems, and the computational complexity of decision-making: (1) Models don't need to be perfectly accurate---they only need to be accurate enough to maintain the relative ordering during action selection; (2) The objective of action selection is not to find the most optimal one, but rather to avoid the worst ones; (3) Creation of models is not a one-time activity---it is a continuous process over the lifetime of the system. (Abstract shortened by UMI.)... | Keywords/Search Tags: | POLUS, Model-based approach, System, OAA automation, Models, Loop, Action | | Related items |
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