Loading...

Dependability Evaluation of Virtual Data Centers in Cloud Environement

Roohitavaf, Mohammad | 2013

512 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 44752 (19)
  4. University: Sharif University of Technology
  5. Department: Computer Engineering
  6. Advisor(s): Movaghar Rahimabadi, Ali
  7. Abstract:
  8. Availability of the service delivered by cloud providers is one of the most important QoS factors of the service level agreements between providers and customers. Since current Infrastructure-as-a-Service providers use virtualization technology to manage data centers,virtual data centers (VDCs) have become a popular infrastructure for cloud computing.Evaluation of VDCs gives cloud providers the oportunnity to improve their service by investigating the effect of different parameters on their service.As a result, they can allocate appropriate amount of resources, and apply better resource management policies.In this study, in order to evaluate different aspects of VDCs, including service availability,an analytical approach by modeling using stochastic activity networks is presented. The results of the analytic approach are validated via discrete-event simulation.Two classes of models have been proposed for different kinds of anagement methods.Models of the first class, accurately calculate the interesting measures concerning system assumptions. However,due to the system complexity, the state space of the models of the first class becomes large for large number of resources. The large state space makes the task of analyzing the system difficult. To solve this difficulty, the second class of models is presented. The models of this class,which work through grouping the resources according to their working load, merge large number of states in the underlying Markov chain which contributes to significant reduction in the number of states of the state space. Results obtained by comparing these two classes show that the amount of error by models of the second class is negligible.In addition, abroad range of possible studies to investigate the effects of variations of different system parameters on interesting me asures are presented in this study. The btained results show how the variations in different system parameters, amount of resources, and different resource management policies can affect the quality of the delivered service.
  9. Keywords:
  10. Cloud Computing ; Availability ; Stochastic Activity Networks ; Virtual Machine ; Virtual Data Center

 Digital Object List

 Bookmark

No TOC