Virtual time-aware virtual machine systems

Yoginath, Srikanth B.

Title:

Virtual time-aware virtual machine systems

dc.contributor.advisor	Perumalla, Kalyan S.
dc.contributor.advisor	Fujimoto, Richard M.
dc.contributor.author	Yoginath, Srikanth B.
dc.contributor.committeeMember	Bader, David A.
dc.contributor.committeeMember	Riley, George F.
dc.contributor.committeeMember	Ramachandran, Umakishore
dc.contributor.department	Computational Science and Engineering
dc.date.accessioned	2014-08-27T13:41:41Z
dc.date.available	2014-08-27T13:41:41Z
dc.date.created	2014-08
dc.date.issued	2014-07-01
dc.date.submitted	August 2014
dc.date.updated	2014-08-27T13:41:41Z
dc.description.abstract	Discrete dynamic system models that track, maintain, utilize, and evolve virtual time are referred to as virtual time systems (VTS). The realization of VTS using virtual machine (VM) technology offers several benefits including fidelity, scalability, interoperability, fault tolerance and load balancing. The usage of VTS with VMs appears in two ways: (a) VMs within VTS, and (b) VTS over VMs. The former is prevalent in high-fidelity cyber infrastructure simulations and cyber-physical system simulations, wherein VMs form a crucial component of VTS. The latter appears in the popular Cloud computing services, where VMs are offered as computing commodities and the VTS utilizes VMs as parallel execution platforms. Prior to our work presented here, the simulation community using VM within VTS (specifically, cyber infrastructure simulations) had little awareness of the existence of a fundamental virtual time-ordering problem. The correctness problem was largely unnoticed and unaddressed because of the unrecognized effects of fair-share multiplexing of VMs to realize virtual time evolution of VMs within VTS. The dissertation research reported here demonstrated the latent incorrectness of existing methods, defined key correctness benchmarks, quantitatively measured the incorrectness, proposed and implemented novel algorithms to overcome incorrectness, and optimized the solutions to execute without a performance penalty. In fact our novel, correctness-enforcing design yields better runtime performance than the traditional (incorrect) methods. Similarly, the VTS execution over VM platforms such as Cloud computing services incurs large performance degradation, which was not known until our research uncovered the fundamental mismatch between the scheduling needs of VTS execution and those of traditional parallel workloads. Consequently, we designed a novel VTS-aware hypervisor scheduler and showed significant performance gains in VTS execution over VM platforms. Prior to our work, the performance concern of VTS over VM was largely unaddressed due to the absence of an understanding of execution policy mismatch between VMs and VTS applications. VTS follows virtual-time order execution whereas the conventional VM execution follows fair-share policy. Our research quantitatively uncovered the exact cause of poor performance of VTS in VM platforms. Moreover, we proposed and implemented a novel virtual time-aware execution methodology that relieves the degradation and provides over an order of magnitude faster execution than the traditional virtual time-unaware execution.
dc.description.degree	Ph.D.
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/1853/52321
dc.language.iso	en_US
dc.publisher	Georgia Institute of Technology
dc.subject	Discrete event simulations
dc.subject	Virtual machines
dc.subject	Hypervisor scheduler
dc.subject	Cloud computing
dc.subject	VM-based network emulation/simulation
dc.subject	Cyber-physical simulations
dc.title	Virtual time-aware virtual machine systems
dc.type	Text
dc.type.genre	Dissertation
dspace.entity.type	Publication
local.contributor.advisor	Fujimoto, Richard M.
local.contributor.corporatename	College of Computing
local.contributor.corporatename	School of Computational Science and Engineering
relation.isAdvisorOfPublication	6b1d5049-6d43-45fa-949c-67e994368423
relation.isOrgUnitOfPublication	c8892b3c-8db6-4b7b-a33a-1b67f7db2021
relation.isOrgUnitOfPublication	01ab2ef1-c6da-49c9-be98-fbd1d840d2b1
thesis.degree.level	Doctoral