Cloud

近年のクラウドコンピューティングの飛躍的な普及の背景には，ソフトウェア技術により計算機資源を仮想化することで，計算機環境の構築・割当を動的か

当研究室の修士課程学生のGuoqing Li君とSUSE LabsのDario Faggioli博士が， KVM Forum 2021 にて “KubeVirt: The cost of Containerizing VMs” という題目で共同研究

当研究室M1のGuoqing Li 君が，クラウドコンピューティングの応用に関する国際会議 11th IEEE International Conference on Cloud Computing and Service Science (CLOSER 2021) にて下記の論文を発表しました: Guoqing

Virtual Machines (VMs) are used extensively in the cloud. The underlying hypervisors allow hardware resources to be split into multiple virtual units which enables server consolidation, fault containment and resource management. However, VMs with traditional architecture introduce heavy overhead and reduce application performance. Containers are becoming popular options for running applications, yet such a solution raises security concerns due to weaker isolation than VMs. We are at the point of container and traditional virtualization convergence where lightweight hypervisors are implemented and integrated into the container ecosystem in order to maximize the benefits of VM isolation and container performance.

Data centers are centralized facilities where computing and networking hardware are aggregated to handle large amounts of data and computation. In a data center, computing resources such as CPU and memory are usually managed by a resource manager. The resource manager accepts resource requests from users and allocates resources to their applications. A commonly known problem in resource management is that users often request more resources than their applications actually use.

Background In recent years, Cloud Gaming, also regarded as gaming on demand, is an emerging gaming service that envisions a promising future of providing million clients with novel and highly accessible gaming experiences, as it has been an active topic both in industries and research fields recently. Compared to Online Game which only stores game status, Cloud Gaming takes more advantages of cloud infrastructures by leveraging reliable, elastic and high-performance computing resources.

A large amount of scientific data needs to be transferred from one site to another as fast as possible in the computational science fields. High-speed data transfer between sites is very important, especially in the Grid computing field; GridFTP has been widely used for bulk data transfer over a wide area network. GridFTP achieves greater performance by supporting parallel TCP streams. Using parallel TCP streams improves the throughput of slow-start algorithms and lossy networks even on a single path.

Bandwidth and latency are two major factors that contribute the most to network application performance. Between each pair of switches in a network, there may be multiple paths connecting them. Each path has different proper- ties because of multiple factors. Traditional shortest-path routing does not take this knowledge into consideration and may result in sub-optimal performance of applications and underutilization of the network. We propose a concept of “bandwidth and latency aware routing”.

Multipath TCP (MPTCP) is an extension to TCP that allows multiple TCP subflows to be created from a single application socket. This is done automatically by operating system kernel implementation, such as MPTCP Kernel. MPTCP has advantages over network layer and application layer multipathing. This is because MPTCP, unlike network layer mechanisms such as Equal-Cost Multipathing (ECMP), is capable of independent congestion control on multiple paths and therefore works well in unequal networks, which is the situation of PRAGMA-ENT.