Madhukar R. Korupolu

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<lb>In this paper, we study approximation algorithms for several NP-hard facility location prob-<lb>lems. We prove that a simple local search heuristic yields polynomial-time constant-factor<lb>approximation bounds for the metric versions of the uncapacitated k-median problem and<lb>the uncapacitated facility location problem. (For the k-median problem, our(More)
We describe the design of an agile data center with integrated server and storage virtualization technologies. Such data centers form a key building block for new cloud computing architectures. We also show how to leverage this integrated agility for non-disruptive load balancing in data centers across multiple resource layers servers, switches, and(More)
In a large-scale information system such as a digital library or the web, a set of distributed caches can improve their eeectiveness by coordinating their data placement decisions. Using simulation, we examine three practical cooperative placement algorithms including one that is provably close to optimal, and we compare these algorithms to the optimal(More)
Virtualization technologies like VMware and Xen provide features to specify the minimum and maximum amount of resources that can be allocated to a virtual machine (VM) and a shares based mechanism for the hypervisor to distribute spare resources among contending VMs. However much of the existing work on VM placement and power consolidation in data centers(More)
Consider a hierarchical network of machines in which each machine periodically issues a request for an object drawn from a fixed set of unit-size objects. Suppose further that the following conditions are satisfied: (i) the frequency with which each machine accesses each object is known, (ii) each machine has a cache of known capacity, (iii) any cache can(More)
We introduce the coupled placement problem for modern data centers spanning placement of application computation and data among available server and storage resources. While the two have traditionally been addressed independently in data centers, two modern trends make it beneficial to consider them together in a coupled manner: (a) rise in virtualization(More)
ion. While graphical zooming changes the scale of the object being viewed, semantic zooming changes the level of information abstraction, for example, zooming out would mean going to a higher level of abstraction. It is often employed in conjunction with progressive disclosure, which provides task-specific presentation and interaction in a sequence of(More)
The logic blocks (CLBs) of a lookup table (LUT) based FPGA consist of one or more LUTs, possibly of different sizes. In this paper, we focus on technology mapping for CLBs with several <italic>independent</italic> LUTs of two different sizes (called ICLBs). The Actel <italic>ES6500</italic> family is an example of a class of commercially available ICLBs.(More)
storage provisioning and disaster recovery S. Gopisetty E. Butler S. Jaquet M. Korupolu T. K. Nayak R. Routray M. Seaman A. Singh C.-H. Tan S. Uttamchandani A. Verma Introducing an application into a data center involves complex interrelated decision-making for the placement of data (where to store it) and resiliency in the event of a disaster (how to(More)
The designers of clustered file systems, storage resource management software and storage virtualization devices are trying to provide the necessary planning functionality in their products to facilitate the invocation of the appropriate corrective actions in order to satisfy user specified service level objectives (SLOs). However, most existing approaches(More)