Akshat Verma - Academia.edu (original) (raw)
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Papers by Akshat Verma
Ec, Dec 10, 2002
We study mechanisms that can be modelled as coalitional games with transferable utilities, and ap... more We study mechanisms that can be modelled as coalitional games with transferable utilities, and apply ideas from mechanism design and game theory to problems arising in a network design setting. We establish an equivalence between the game-theoretic notion of agents being substitutes and the notion of frugality of a mechanism. We characterize the core of the network design game and relate it to outcomes in a sealed bid auction with VCG payments. We show that in a game, agents are substitutes if and only if the core of the forms a complete lattice. We look at two representative games-Minimum Spanning Tree and Shortest Path-in this light.
Acm Sigmetrics Performance Evaluation Review, 2011
Abstract Data center consolidation has emerged as an important tool to improve the hardware utili... more Abstract Data center consolidation has emerged as an important tool to improve the hardware utilization of data centers and reduce delivery costs. Consolidation has traditionally used virtualization to consolidate multiple workloads as different virtual ...
Proceedings of the 2009 Conference on Usenix Annual Technical Conference, Jun 14, 2009
Server consolidation has emerged as a promising technique to reduce the energy costs of a data ce... more Server consolidation has emerged as a promising technique to reduce the energy costs of a data center. In this work, we present the first detailed analysis of an enterprise server workload from the perspective of finding characteristics for consolidation. We observe significant potential for power savings if consolidation is performed using off-peak values for application demand. However, these savings come up with associated risks due to consolidation, particularly when the correlation between applications is not considered. We also investigate the stability in utilization trends for low-risk consolidation. Using the insights from the workload analysis, two new consolidation methods are designed that achieve significant power savings, while containing the performance risk of consolidation. We present an implementation of the methodologies in a consolidation planning tool and provide a comprehensive evaluation study of the proposed methodologies.
Writing data within user or operating system memory often encounters the classic read-before-writ... more Writing data within user or operating system memory often encounters the classic read-before-write problem whereby the page written to must first be read from the backing store, effectively blocking the writing process before modifications are made. Unfortunately, the large gap between memory and storage access performance adversely affects workloads that require substantial readbefore-write operations when accessing memory. In this paper, we present techniques that make writes to memory truly non-blocking. The basic approach involves absorbing writes immediately in temporary buffer pages and asynchronously merging the updates after reading in the on-disk version of the page. Doing so improves system performance by first, reducing blocking of processes and second, improving the parallelism of data retrieval from the backing store leading to better throughput for readbefore-write operations. We analyze the potential benefits of our approach using full-system memory access traces for several benchmark workloads and present techniques that commodity operating systems can employ to implement non-blocking writes.
We study mechanisms that can be modelled as coalitional games with transferable utilities, and ap... more We study mechanisms that can be modelled as coalitional games with transferable utilities, and apply ideas from mechanism design and game theory to problems arising in a network design setting. We establish an equivalence between the game-theoretic notion of agents being substitutes and the notion of frugality of a mechanism. We characterize the core of the network design game and relate it to outcomes in a sealed bid auction with VCG payments. We show that in a game, agents are substitutes if and only if the core of the forms a complete lattice. We look at two representative games-Minimum Spanning Tree and Shortest Path-in this light.
Proceedings of the 15th International Middleware Conference, Dec 8, 2014
Ec, Dec 10, 2002
We study mechanisms that can be modelled as coalitional games with transferable utilities, and ap... more We study mechanisms that can be modelled as coalitional games with transferable utilities, and apply ideas from mechanism design and game theory to problems arising in a network design setting. We establish an equivalence between the game-theoretic notion of agents being substitutes and the notion of frugality of a mechanism. We characterize the core of the network design game and relate it to outcomes in a sealed bid auction with VCG payments. We show that in a game, agents are substitutes if and only if the core of the forms a complete lattice. We look at two representative games-Minimum Spanning Tree and Shortest Path-in this light.
Acm Sigmetrics Performance Evaluation Review, 2011
Abstract Data center consolidation has emerged as an important tool to improve the hardware utili... more Abstract Data center consolidation has emerged as an important tool to improve the hardware utilization of data centers and reduce delivery costs. Consolidation has traditionally used virtualization to consolidate multiple workloads as different virtual ...
Proceedings of the 2009 Conference on Usenix Annual Technical Conference, Jun 14, 2009
Server consolidation has emerged as a promising technique to reduce the energy costs of a data ce... more Server consolidation has emerged as a promising technique to reduce the energy costs of a data center. In this work, we present the first detailed analysis of an enterprise server workload from the perspective of finding characteristics for consolidation. We observe significant potential for power savings if consolidation is performed using off-peak values for application demand. However, these savings come up with associated risks due to consolidation, particularly when the correlation between applications is not considered. We also investigate the stability in utilization trends for low-risk consolidation. Using the insights from the workload analysis, two new consolidation methods are designed that achieve significant power savings, while containing the performance risk of consolidation. We present an implementation of the methodologies in a consolidation planning tool and provide a comprehensive evaluation study of the proposed methodologies.
Writing data within user or operating system memory often encounters the classic read-before-writ... more Writing data within user or operating system memory often encounters the classic read-before-write problem whereby the page written to must first be read from the backing store, effectively blocking the writing process before modifications are made. Unfortunately, the large gap between memory and storage access performance adversely affects workloads that require substantial readbefore-write operations when accessing memory. In this paper, we present techniques that make writes to memory truly non-blocking. The basic approach involves absorbing writes immediately in temporary buffer pages and asynchronously merging the updates after reading in the on-disk version of the page. Doing so improves system performance by first, reducing blocking of processes and second, improving the parallelism of data retrieval from the backing store leading to better throughput for readbefore-write operations. We analyze the potential benefits of our approach using full-system memory access traces for several benchmark workloads and present techniques that commodity operating systems can employ to implement non-blocking writes.
We study mechanisms that can be modelled as coalitional games with transferable utilities, and ap... more We study mechanisms that can be modelled as coalitional games with transferable utilities, and apply ideas from mechanism design and game theory to problems arising in a network design setting. We establish an equivalence between the game-theoretic notion of agents being substitutes and the notion of frugality of a mechanism. We characterize the core of the network design game and relate it to outcomes in a sealed bid auction with VCG payments. We show that in a game, agents are substitutes if and only if the core of the forms a complete lattice. We look at two representative games-Minimum Spanning Tree and Shortest Path-in this light.
Proceedings of the 15th International Middleware Conference, Dec 8, 2014