Wide-area live migration of virtual machines (VMs) is a key to advanced cloud federation, allowing dynamic and transparent load balancing among data centers. Although Mobile IPv6 (MIPv6) provides strong network infrastructure for mobile nodes, there still exists a missing link to the achievement of MIPv6-based VM migration. Real-world IaaS datacenters require guest-transparent and flexible tunneling mechanisms, which are not provided by existing MIPv6 programs. In this paper, we propose a guest-transparent MIPv6 tunneling mechanism (Kagemusha), that performs Client MIPv6 signaling and tunneling on a host operating system. No MIPv6 program is required to be installed into a guest operating system. The proposed system is fully compatible with existing home agents. It basically works with most virtual machine monitors, including Qemu/KVM and Xen. We have developed the first proof-of-concept prototype of the proposed mechanism. Our experiments showed that our prototype system successfully created MIPv6 tunnels with existing home agents. Its performance overhead was negligible for normal use cases. We also confirmed that the prototype system successfully supported live migration, transparently achieving continuous network reachability for migrated VMs. The downtime of migration increased only by several hundred milliseconds.

We are developing an efficient resource management system with aggressive virtual machine (VM) relocation among physical nodes in a data center. Existing live migration technology, however, requires a long time to change the execution host of a VM, it is difficult to optimize VM packing on physical nodes dynamically, corresponding to ever-changing resource usage. In this paper, we propose an advanced live migration mechanism enabling instantaneous relocation of VMs. To minimize the time needed for switching the execution host, memory pages are transferred after a VM resumes at a destination host. A special character device driver allows transparent memory page retrievals from a source host for the running VM at the destination. In comparison with related work, the proposed mechanism supports guest operating systems without any modifications to them (i.e, no special device drivers and programs are needed in VMs). It is implemented as a lightweight extension to KVM (Kernel-based Virtual Machine Monitor). It is not required to modify critical parts of the VMM code. Experiments were conducted using the SPECweb2005 benchmark. A running VM with heavily-loaded web servers was successfully relocated to a destination within one second. Temporal performance degradation after relocation was resolved by means of a precaching mechanism for memory pages. In addition, for memory intensive workloads, our migration mechanism moved all the states of a VM faster than existing migration technology.

IaaS (Infrastructure-as-a-Service) is an emerging concept of cloud computing, which allows users to obtain hardware resources from virtualized data centers. Although many commercial IaaS clouds have recently been launched, dynamic virtual machine (VM) migration is not possible among service providers; users are locked into a particular provider, and cannot transparently relocate their VMs to another one for the best cost-effectiveness. In this paper, we propose an advanced storage access mechanism that strongly supports live VM migration over WAN. It rapidly relocates VM disks between source and destination sites with the minimum impact on I/O performance. The proposed mechanism addresses I/O consistency of virtual disks before/after migration, which is the major issue regarding wide-area live migration. The proposed mechanism works as a storage server of a block-level storage I/O protocol (e.g.,iSCSI and NBD). Two key techniques (on-demand fetching and background copying) move on-line virtual disks among remote sites, transparently and efficiently. Our prototype system works perfectly for Xen and KVM without any modification to them. Experiments showed the prototype system also worked successfully for an emulated WAN environment.

Abstract One of the greatest evolutions brought about by Grid technology is ‘Grid utility computing’, which utilizes various kinds of IT resources and applications across multiple organizations and enterprises, and integrates them into a comprehensive and valuable service. Since 2004, we proposed and have been developing the GridASP framework, which realizes Grid‐enabled application service providers (ASPs) in order to realize Grid utility computing. GridASP can bind application providers, resource providers, and service providers together and provide application execution services with security and anonymity to enterprise/science users. In this article, we report the conceptual idea of GridASP and the detail of the framework now being developed. Information on GridASP can be found at http://www.gridasp.org . Copyright © 2006 John Wiley & Sons, Ltd.

The current technology of parallel and distributed systems allows users to exploit a variety of resources across networks. However, the support provided is often insufficient for computational scientists to simulate complicated real-world scenarios in which different kinds of scientific applications need to be combined to perform high fidelity simulations. As a result, users waste a large amount of time and effort developing custom techniques for performing semantic-level communication between heterogeneous scientific simulations. This paper describes a new middleware system that provides high-level transparency in the form of agents that automatically transfer and transform data between simulations that use different mathematical and physical modeling approaches. Based on a specification that correlates different discrete points in finite difference method (FDM), finite element method (FEM) or particle simulations, the agents provide a variety of techniques for semantically transforming the values associated with correlated points and automatically determine to which processes the values must be transferred. To facilitate use and minimize impact on user programs, the agent system includes three types of library calls that manage task identification, register different kinds of discrete points and construct a correlation table according to the specification, and transfer messages that incorporate extraction and transformation of the values on the correlated points. Another library specially optimized for parallel simulations that use a SPMD (Single Program Multiple Data stream) structure is also offered to control communication through the agents. A prototype system has been developed on the Hitachi SR2201 parallel machine as well as workstation clusters, and applied to several example applications. These include an advanced device simulation that combines quantum transport simulation with electric potential simulation, and a simulation of thermal flow resulting from high-frequency device operation that hybridizes molecular dynamics simulation with macroscopic continuum simulation. These combinations can be efficiently realized using the small number of library calls within the agent system together with additional routines that change the data formats of discrete points. The time overhead of the agent calculations is shown experimentally to agree closely with the theoretically-predicted values modeled as a function of the number of discrete points and domain decomposition in parallel simulations. This value becomes insignificant compared with that of the simulation processes for heterogeneous large-scale simulations.