Design & Implementation Of Virtual Data Center Dynamic Performance Control System

Today's data center often employs virtualization to allow multiple enterprise ap-plications to share a common hosting platform in order to improve resource and spaceutilization. However, current virtualization technologies are inadequate in achievingapplication-level quality of service (QoS) goals with time-varying demands for mul-tiple resources. In addition, it could be a greater challenge when the shared serverbecomes overloaded or enforces priority of the common resource among applicationsin such an environment.In this paper, we propose a feedback-based dynamical resource allocation systemwhich is applied for such complex application can dynamically adjust the resourceshares to multiple virtual machine nodes and workload generation schemes in order toachieve application-level SLOs on shared virtualized infrastructure, which is the mostimportant innovation of the system. The control system parameters are automaticallytuned at the system's runtime based on two control part. The first part is an onlinemodel estimator using a recursive least-squares (RLS) method to capture the complexrelationship between application performance and resource allocations. The second isan optimal controller using a quadratic cost function to allocate the optimal amountof resources to ensure application-level QoS. To evaluate our controller design, webuilt a testbed hosting several virtual machines which employed Xen Virtual MachineMonitor (VMM), and using Apache server along with its workload-generate tool. Ourexperiment results indicate that our controller is able to detect and adapt to resourcerequirement that changes over time and allocate virtualized resources accordingly toachieve application-level QoS.The innovations of the paper are as follows:1. Dynamic relationship model of resources and performance: The system dynam- ically builds the relationship model between virtual machine resources and per-formance during operation. The system uses fine-grained linear relationshipmodel to approximate non-linear model, which can make the model much accu-rate.2. Dynamic resource allocation system: The system uses historical data to predictan optimal resource allocated to each virtual machine next time to meet the pre-set performance goal.3. Integrated virtual data center test platform: From the platform's testing, Wecan find that our system no only can meet the pre-set QoS target, but also itsstability and efficiency are far superior than the static resource allocation of Xenown strategy. The test platform integrates Xen virtual machine, Apache serverand other key technologies, which make it can be widely applied in the relevantvirtual machine performance analysis and system modeling process.The paper is structured as follows: first giving a brief introduction of the researchstatus of the performance of virtualization technology ensuring and related areas. Thentaking a description in detail of some of our methods and techniques the system used,such as virtualization technology, system identification and modeling process, opti-mal control theory and other core algorithms. Next presents the general framework ofthe whole control system design and various functions of main modules and the imple-mentation methods. At last we describe and analysis the experiment results of the con-trol system in a real test virtual data center platform experimental environment. Thispaper fully describe the design and implementation of a dynamic resource allocationsystem of virtual servers which based on feedback control theory and virtualizationtechnology. It has a certain value for future research on performance optimization ofvirtualization technology and system modeling.