Pierre Riteau

Shrinker: improving live migration of virtual clusters over WANs with distributed data deduplication and content-based addressing

Live virtual machine migration is a powerful feature of virtualization technologies. It enables efficient load balancing, reduces energy consumption through dynamic consolidation, and makes infrastructure maintenance transparent to users.While live migration is available across wide area networks with state of the art systems, it remains expensive to use because of the large amounts of data to transfer, especially when migrating virtual clusters rather than single virtual machine instances. As evidenced by previous research, virtual machines running identical or similar operating systems have significant portions of their memory and storage containing identical data. We propose Shrinker, a live virtual machine migration system leveraging this common data to improve live virtual cluster migration between data centers interconnected by wide area networks. Shrinker detects memory pages and disk blocks duplicated in a virtual cluster to avoid sending multiple times the same content over WAN links. Virtual machine data is retrieved in the destination site with distributed content-based addressing. We implemented a prototype of Shrinker in the KVM hypervisor and present a performance evaluation in a distributed environment. Experiments show that it reduces both total data transferred and total migration time.

User-level virtual networking mechanisms to support virtual machine migration over multiple clouds

Dynamic allocation of multiple cloud resources adapting to application needs over time can be achieved by taking advantage of wide-area VM live migration technologies. However, migration of VMs across different subnets, potentially in multiple clouds, requires networking support to keep the network state of moving VMs unchanged. Two problems make traditional solutions to machine mobility inefficient in this scenario: (1) administrative overheads due to coordination requirements between moving machines and the network infrastructure; and (2) degraded network performance of machines moved away from their “home” networks. New solutions are needed to efficiently support the migration of virtual machines over multiple cloud providers. The user-level virtual network architecture presented in this paper implements mechanisms to allow VM migration over clouds without requiring support from the physical network infrastructure, and automatically reconfiguring virtual networks to maximize the network performance of migrated virtual machines.

Clouds: a New Playground for the XtreemOS Grid Operating System

The emerging cloud computing model has recently gained a lot of interest both from commercial companies and from the research community. XtreemOS is a distributed operating system for large-scale wide-area dynamic infrastructures spanning multiple administrative domains. XtreemOS, which is based on the Linux operating system, has been designed as a Grid operating system providing native support for virtual organizations. In this paper, we discuss the positioning of XtreemOS technologies with regard to cloud computing. More specifically, we investigate a scenario where XtreemOS could help users take full advantage of clouds in a global environment including their own resources and cloud resources. We also discuss how the XtreemOS system could be used by cloud service providers to manage their underlying infrastructure. This study shows that the XtreemOS distributed operating system is a highly relevant technology in the new era of cloud computing where future clouds seamlessly span multiple bare hardware providers and where customers extend their IT infrastructure by provisioning resources from different cloud service providers.

Shrinker: efficient live migration of virtual clusters over wide area networks

Live virtual machine migration is a powerful feature of virtualization technologies. It enables efficient load balancing, reduces energy consumption through dynamic consolidation, and makes infrastructure maintenance transparent to users. Although live migration is available across wide area networks with state of the art systems, it remains expensive to use because of the large amounts of data to transfer, especially when migrating virtual clusters rather than single virtual machine instances. As evidenced by previous research, virtual machines running identical or similar operating systems have significant portions of their memory and storage containing identical data. We propose Shrinker, a live virtual machine migration system leveraging this common data to improve live virtual cluster migration between data centers interconnected by wide area networks. Shrinker detects memory pages and disk blocks duplicated in a virtual cluster to avoid sending the same content multiple times over wide‐area network links. Virtual machine data is retrieved in the destination site with distributed content‐based addressing. We implemented a prototype of Shrinker in the KVM (Kernel‐based Virtual Machine) hypervisor and present a performance evaluation in a distributed environment. Experiments show that it reduces both total data transferred and total migration time. Copyright

Building Dynamic Computing Infrastructures over Distributed Clouds

The emergence of cloud computing infrastructures brings new ways to build and manage computing systems, with the flexibility offered by virtualization technologies. In this context, this PhD thesis focuses on two principal objectives. First, leveraging virtualization and cloud computing infrastructures to build distributed large scale computing platforms from multiple cloud providers, allowing to run software requiring large amounts of computation power. Second, developing mechanisms to make these infrastructures more dynamic. These mechanisms, providing inter-cloud live migration, offer new ways to exploit the inherent dynamic nature of distributed clouds.

High availability on cloud with HA-OSCAR

Cloud computing provides virtual resources so that end-users or organizations can buy computing power as a public utility. Cloud service providers however must strive to ensure good QoS by offering highly available services with dynamically scalable resources. HA-OSCAR is an open source High Availability (HA) solution for HPC/cloud that offers component redundancy, failure detection, and automatic fail-over. In this paper, we describe HA-OSCAR as a cloud platform and analyze system availability of two potential cloud computing systems, OSCAR-V cluster and HA-OSCAR-V. We also explore our case study to improve Nimbus, a popular cloud IaaS toolkit. The results show that the system that deploys HA-OSCAR has a significantly higher degree of availability.