Resource Reconstruction Algorithms for On-demand Allocation in Virtual Computing Resource Pool

Resource reconstruction algorithms are studied in this paper to solve the problem of resource on-demand allocation and improve the efficiency of resource utilization in virtual computing resource pool. Based on the idea of resource virtualization and the analysis of the resource status transition, the resource allocation process and the necessity of resource reconstruction are presented, l^esource reconstruction algorithms are designed to determine the resource reconstruction types, and it is shown that they can achieve the goal of resource on-demand allocation through three methodologies： resource combination, resource split, and resource random adjustment. The effects that the resource users have on the resource reconstruction results, the deviation between resources and requirements, and the uniformity of resource distribution are studied by three experiments. The experiments show that resource reconstruction has a close relationship with resource requirements, but it is not the same with current distribution of resources. The algorithms can complete the resource adjustment with a lower cost and form the logic resources to match the demands of resource users easily.

Internet-based virtual computing environment(iVCE):Concepts and architecture

Resources over Internet have such intrinsic characteristics as growth, autonomy and diversity, which have brought many challenges to the efficient sharing and comprehensive utilization of these resources. This paper presents a novel approach for the construction of the Internet-based Virtual Computing Environment （iVCE）, whose sig- nificant mechanisms are on-demand aggregation and autonomic collaboration. The iVCE is built on the open infrastructure of the Internet and provides harmonious, transparent and integrated services for end-users and applications. The concept of iVCE is presented and its architectural framework is described by introducing three core concepts, i.e., autonomic element, virtual commonwealth and virtual executor. Then the connotations, functions and related key technologies of each components of the architecture are deeply analyzed with a case study, iVCE for Memory.

A Programming Language Approach to Internet-Based Virtual Computing Environment

There is an increasing need to build scalable distributed systems over the Internet infrastructure. However the development of distributed scalable applications suffers from lack of a wide accepted virtual computing environment. Users have to take great efforts on the management and sharing of the involved resources over Internet, whose characteristics are intrinsic growth, autonomy and diversity. To deal with this challenge, Internet-based Virtual Computing Environment （iVCE） is proposed and developed to serve as a platform for distributed scalable applications over the open infrastructure, whose kernel mechanisms are on-demand aggregation and autonomic collaboration of resources. In this paper, we present a programming language for iVCE named Owlet. Owlet conforms with the conceptual model of iVCE, and exposes the iVCE to application developers. As an interaction language based on peer-to-peer content-based publish/subscribe scheme, Owlet abstracts the Internet as an environment for the roles to interact, and uses roles to build a relatively stable view of resources for the on-demand resource aggregation. It provides language constructs to use 1） distributed event driven rules to describe interaction protocols among different roles, 2） conversations to correlate events and rules into a common context, and 3） resource pooling to do fault tolerance and load balancing among networked nodes. We have implemented an Owlet compiler and its runtime environment according to the architecture of iVCE, and built several Owlet applications, including a peer-to-peer file sharing application. Experimental results show that, with iVCE, the separation of resource aggregation logic and business logic significantly eases the process of building scalable distributed applications.

Mucosa-associated lymphoid tissue lymphoma of the trachea treated with radiotherapy:A case report

BACKGROUND Mucosa-associated lymphoid tissue(MALT)lymphoma originates in the marginal zone of lymphoid tissue.lung is one of the most frequent non-gastrointestinal organs involved,here known as bronchus-associated lymphoid tissue(BALT)lymphoma.BALT lymphoma of unknown etiology,and most patients are asymptomatic.The treatment of BALT lymphoma is controversial.CASE SUMMARY A 55-year-old man admitted to hospital had a three-month history of progressively coughing up yellow sputum,chest stuffiness,and shortness of breath.Fiberoptic bronchoscopy revealed mucosal visible beaded bumps 4 cm from the tracheal carina at 9 o'clock and 3 o'clock,the right main bronchus,and the right upper lobe bronchus.Biopsy specimens showed MALT lymphoma.Computed tomography virtual bronchoscopy(CTVB)showed uneven main bronchial wall thickening and multiple nodular protrusion.BALT lymphoma stage IE was diagnosed after a staging examination.We treated the patient with radiotherapy(RT)alone.A total dose of 30.6 Gy/17 f/25 d was given.The patient had no obvious adverse reactions during RT.The CTVB was repeated after RT and showed that the right side of the trachea was slightly thickened.CTVB was repeated 1.5 mo after RT and again showed that the right side of the trachea was slightly thickened.Annual CTVB showed no signs of recurrence.The patient now has no symptoms.CONCLUSION BALT lymphoma is an uncommon disease and shows good prognosis.The treatment of BALT lymphoma is controversial.In recent years,less invasive diagnostic and therapeutic approaches have been emerging.RT was effective and safe in our case.The use of CTVB could provide a noninvasive,repeatable,and accurate method in diagnosis and follow-up.

Evaluation of Hypervisor Stability towards Insider Attacks

Virtualization technology plays a key role in cloud computing.Thus,the security issues of virtualization tools（hypervisors,emulators,etc.） should be under precise consideration.However,threats of insider attacks are underestimated.The virtualization tools and hypervisors have been poorly protected from this type of attacks.Furthermore,hypervisor is one of the most critical elements in cloud computing infrastructure.Firstly,hypervisor vulnerabilities analysis is provided.Secondly,a formal model of insider attack on hypervisor is developed.Consequently,on the basis of the formal attack model,we propose a new methodology of hypervisor stability evaluation.In this paper,certain security countermeasures are considered that should be integrated in hypervisor software architecture.

Deadline based scheduling for data-intensive applications in clouds

Cloud computing emerges as a new computing pattern that can provide elastic services for any users around the world. It provides good chances to solve large scale scientific problems with fewer efforts. Application deployment remains an important issue in clouds. Appropriate scheduling mechanisms can shorten the total completion time of an application and therefore improve the quality of service（QoS） for cloud users. Unlike current scheduling algorithms which mostly focus on single task allocation, we propose a deadline based scheduling approach for data-intensive applications in clouds. It does not simply consider the total completion time of an application as the sum of all its subtasks＇ completion time. Not only the computation capacity of virtual machine（VM） is considered, but also the communication delay and data access latencies are taken into account. Simulations show that our proposed approach has a decided advantage over the two other algorithms.