Reboot-based Recovery of Performance Anomalies in Adaptive Bitrate Video-Streaming Services

Performance anomalies represent one common type of failures in Internet servers. Overcoming these failures without introducing server downtimes is of the utmost importance in video-streaming services. These services have large user abandon- ment costs when failures occur after users watch a significant part of a video. Reboot is the most popular and effective technique for overcoming performance anomalies but it takes several minutes from start until the server is warmed-up again to run at its full capacity. During that period, the server is unavailable or provides limited capacity to process end-users’ requests. This paper presents a recovery technique for performance anomalies in HTTP Streaming services, which relies on Container-based Virtualization to implement an efficient multi-phase server reboot technique that minimizes the service downtime. The recovery process includes analysis of variance of request-response times to delimit the server warm-up period, after which the server is running at its full capacity. Experimental results show that the Virtual Container recovery process completes in 72 seconds, which contrasts with the 434 seconds required for full operating system recovery. Both recovery types generate service downtimes imperceptible to end-users

Dynamic and Transparent Analysis of Commodity Production Systems

We propose a framework that provides a programming interface to perform complex dynamic system-level analyses of deployed production systems. By leveraging hardware support for virtualization available nowadays on all commodity machines, our framework is completely transparent to the system under analysis and it guarantees isolation of the analysis tools running on its top. Thus, the internals of the kernel of the running system needs not to be modified and the whole platform runs unaware of the framework. Moreover, errors in the analysis tools do not affect the running system and the framework. This is accomplished by installing a minimalistic virtual machine monitor and migrating the system, as it runs, into a virtual machine. In order to demonstrate the potentials of our framework we developed an interactive kernel debugger, nicknamed HyperDbg. HyperDbg can be used to debug any critical kernel component, and even to single step the execution of exception and interrupt handlers.Comment: 10 pages, To appear in the 25th IEEE/ACM International Conference on Automated Software Engineering, Antwerp, Belgium, 20-24 September 201

Protecting Private Data in the Cloud

Companies that process business critical and secret data are reluctant to use utility and cloud computing for the risk that their data gets stolen by rogue system administrators at the hosting company. We describe a system organization that prevents host administrators from directly accessing or installing eaves-dropping software on the machine that holds the client's valuable data. Clients are monitored via machine code probes that are inlined into the clients' programs at runtime. The system enables the cloud provider to install and remove software probes into the machine code without stopping the client's program, and it prevents the provider from installing probes not granted by the client

Virtualization based password protection against malware in untrusted operating systems

Ministry of Education, Singapore under its Academic Research Funding Tier

HIL: designing an exokernel for the data center

We propose a new Exokernel-like layer to allow mutually untrusting physically deployed services to efficiently share the resources of a data center. We believe that such a layer offers not only efficiency gains, but may also enable new economic models, new applications, and new security-sensitive uses. A prototype (currently in active use) demonstrates that the proposed layer is viable, and can support a variety of existing provisioning tools and use cases.Partial support for this work was provided by the MassTech Collaborative Research Matching Grant Program, National Science Foundation awards 1347525 and 1149232 as well as the several commercial partners of the Massachusetts Open Cloud who may be found at http://www.massopencloud.or

Securing Virtualized System via Active Protection

Virtualization is the predominant enabling technology of current cloud infrastructure

Power Management in Grid Computing with Xen

International audienceWhile chip vendor still stick to Moore's law, and the performance per dollar keeps going up, the performance per watt has been stagnant for the last few years. Moreover energy prices continue to rise world-wide. This poses a major challenge to organisations running grids, indeed such architectures require cooling systems. Indeed the one-year cost of a cooling system and of the power consumption may outfit the grid initial investement. We observe , however, that a grid does not constantly run at peak performance. In this paper, we propose a workload concentration strategy to reduce grid power consumption. Using the Xen virtual machine migration technology, our power management policy can dispatch transparently and dynamically any applications of the grid. Our policy concentrates the workload to shutdown nodes that are unused with a neglectable impact on performance. We show through evaluations that this policy decreases the overall power consumption of the grid significantl

Virtualization for computational scientists

International audienc

Green it Parvasiveness in Business Activities Towards Environmental Conservation

Every company, partucularly IT business is facing a challenge in performing business practices that complied with the enviromental conservation. As a response, IT sector had fostered an initiatif identified as ‘Green IT’ which is a practice of designing, manufacturing, using and disposing of IT equipments with less damage to the enviroment. Implementing green IT practices will assist a company to respond to its moral abligation in preserving the environment and abiding in government regulation. Nevertheless, a company has to consider some challenges in praticing green IT such as investing in IT hardware and infrastucture without sacrificing its profitability. At last, the green IT initiatives will be beneficial for the company in creating competitive advantages and to be able to sustain its business performance. &nbsp

Live migration on ARM-based micro-datacentres

Live migration, underpinned by virtualisation technologies, has enabled improved manageability and fault tolerance for servers. However, virtualised server infrastructures suffer from significant processing overheads, system inconsistencies, security issues and unpredictable performance which makes them unsuitable for low-power and resource-constraint computing devices that processing latency-sensitive, 'Big-data'-type data. Consequently, we ask: 'How do we eliminate the overhead of virtualisation whilst still retaining its benefits?' Motivated by this question, we investigate a practical approach for a bare-metal live migration scheme for ARM-based instances low-power servers and edge devices. In this paper, we position ARM-based bare-metal live migration as a technique that will underpin the efficiency on edge-computing and on Micro-datacentres. We also introduce our early work on identifying three key technical challenges and discuss their solutions