Nagarajan Kandasamy

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There is growing incentive to reduce the power consumed by large-scale data centers that host online services such as banking, retail commerce, and gaming. Virtualization is a promising approach to consolidating multiple online services onto a smaller number of computing resources. A virtualized server environment allows computing resources to be shared(More)
Embedded control applications such as drive-by-wire in cars require dependable interaction between various sensors, processors, and actuators. This paper addresses the design of low-cost communication networks guaranteeing to meet both the performance and fault-tolerance requirements of such distributed applications. We develop a fault-tolerant allocation(More)
This paper develops an online resource provisioning framework for combined power and performance management in a virtualized computing environment serving session-based workloads. We pose this management problem as one of sequential optimization under uncertainty and solve it using limited lookahead control (LLC), a form of model-predictive control. The(More)
There is growing incentive to reduce the power consumed by data centers. Virtualization is a promising approach to consolidating multiple online services onto a smaller number of computing resources. By dynamically provisioning virtual machines, consolidating the workload, and turning servers on and off as needed, data center operators can maintain desired(More)
Utility or on-demand computing, a provisioning model where a service provider makes computing infrastructure available to customers as needed, is becoming increasingly common in enterprise computing systems. Realizing this model requires making dynamic, and sometimes risky, resource provisioning and allocation decisions in an uncertain operating environment(More)
Advanced automotive control applications such as steer-by-wire are typically implemented as distributed systems comprising many embedded processors, sensors, and actuators interacting via a communication bus. They have severe cost constraints, but demand a high level of safety and performance. Motivated by the need for timely diagnosis of faulty actuators(More)
Dependable computer systems hosting critical commerce, transportation, and military applications, among others, must satisfy stringent quality-of-service (QoS) requirements. However, as these systems become increasingly complex, maintaining the desired QoS by manually tuning the numerous performance-related parameters are very difficult. This paper develops(More)
The increasing heterogeneity, dynamism and uncertainty of emerging DCE (Distributed Computing Environment) systems imply that an application must be able to detect and adapt to changes in its state, its requirements and the state of the system to meet its desired QoS constraints. As system and application scales increase, ad hoc heuristic-based approaches(More)
This paper addresses adaptive performance management of real-time computing systems. We consider a generic model-based predictive control approach that can be applied to a variety of computing applications in which the system performance must be tuned using a finite set of control inputs. The paper focuses on several key aspects affecting the application of(More)
This paper develops a scalable online optimization framework for the autonomic performance management of distributed computing systems operating in a dynamic environment to satisfy desired quality-ofservice objectives. To efficiently solve the performance management problems of interest in a distributed setting, we develop a hierarchical structure where a(More)