On the Fly Orchestration of Unikernels: Tuning and Performance Evaluation of Virtual Infrastructure Managers

Network operators are facing significant challenges meeting the demand for more bandwidth, agile infrastructures, innovative services, while keeping costs low. Network Functions Virtualization (NFV) and Cloud Computing are emerging as key trends of 5G network architectures, providing flexibility, fast instantiation times, support of Commercial Off The Shelf hardware and significant cost savings. NFV leverages Cloud Computing principles to move the data-plane network functions from expensive, closed and proprietary hardware to the so-called Virtual Network Functions (VNFs). In this paper we deal with the management of virtual computing resources (Unikernels) for the execution of VNFs. This functionality is performed by the Virtual Infrastructure Manager (VIM) in the NFV MANagement and Orchestration (MANO) reference architecture. We discuss the instantiation process of virtual resources and propose a generic reference model, starting from the analysis of three open source VIMs, namely OpenStack, Nomad and OpenVIM. We improve the aforementioned VIMs introducing the support for special-purpose Unikernels and aiming at reducing the duration of the instantiation process. We evaluate some performance aspects of the VIMs, considering both stock and tuned versions. The VIM extensions and performance evaluation tools are available under a liberal open source licence

SEUSS: rapid serverless deployment using environment snapshots

Modern FaaS systems perform well in the case of repeat executions when function working sets stay small. However, these platforms are less effective when applied to more complex, large-scale and dynamic workloads. In this paper, we introduce SEUSS (serverless execution via unikernel snapshot stacks), a new system-level approach for rapidly deploying serverless functions. Through our approach, we demonstrate orders of magnitude improvements in function start times and cacheability, which improves common re-execution paths while also unlocking previously-unsupported large-scale bursty workloads.Published versio

Doctor of Philosophy

dissertationA modern software system is a composition of parts that are themselves highly complex: operating systems, middleware, libraries, servers, and so on. In principle, compositionality of interfaces means that we can understand any given module independently of the internal workings of other parts. In practice, however, abstractions are leaky, and with every generation, modern software systems grow in complexity. Traditional ways of understanding failures, explaining anomalous executions, and analyzing performance are reaching their limits in the face of emergent behavior, unrepeatability, cross-component execution, software aging, and adversarial changes to the system at run time. Deterministic systems analysis has a potential to change the way we analyze and debug software systems. Recorded once, the execution of the system becomes an independent artifact, which can be analyzed offline. The availability of the complete system state, the guaranteed behavior of re-execution, and the absence of limitations on the run-time complexity of analysis collectively enable the deep, iterative, and automatic exploration of the dynamic properties of the system. This work creates a foundation for making deterministic replay a ubiquitous system analysis tool. It defines design and engineering principles for building fast and practical replay machines capable of capturing complete execution of the entire operating system with an overhead of several percents, on a realistic workload, and with minimal installation costs. To enable an intuitive interface of constructing replay analysis tools, this work implements a powerful virtual machine introspection layer that enables an analysis algorithm to be programmed against the state of the recorded system through familiar terms of source-level variable and type names. To support performance analysis, the replay engine provides a faithful performance model of the original execution during replay

Linux-based virtualization for HPC clusters

International audienceThere has been an increasing interest in virtualization in the HPC community, as it would allow to easily and efficiently share computing resources between users, and provide a simple solution for checkpointing. However, virtualization raises a number of interesting questions, on performance and overhead, of course, but also on the fairness of the sharing. In this work, we evaluate the suitability of KVM virtual machines in this context, by comparing them with solutions based on Xen. We also outline areas where improvements are needed, to provide directions for future works

Secure Integration of Desktop Grids and Compute Clusters Based on Virtualization and Meta-Scheduling

Reducing the cost for business or scientific computations, is a commonly expressed goal in today’s companies. Using the available computers of local employees or the outsourcing of such computations are two obvious solutions to save money for additional hardware. Both possibilities exhibit security related disadvantages, since the deployed software and data can be copied or tampered if appropriate countermeasures are not taken. In this paper, an approach is presented to let a local desktop machines and remote cluster resources be securely combined into a singel Grid environment. Solutions to several problems in the areas of secure virtual networks, meta-scheduling and accessing cluster schedulers from desktop Grids are proposed

Final Report on the Evaluation of StratusLab Products

Over the course of the project, the project's software releases have been evaluated against identified requirements and against the needs of real users. Most of the formal requirements have been satisfied, with work in the second year concentrating on extentions to commercial applications, multi-platform support and sandboxing. Feedback from applications running on the StratusLab cloud can be grouped into four broad categories: Ease of Use, Integration & Operation, Better Informaton Flow, and High-Level Services. These categories provide a broad roadmap for the evolution of the StratusLab cloud distribution past the end of the project

Tutkimus virtualisoinnista ja energiatehokkuudesta Linuxilla

Virtualization has in recent years risen in popularity to the extent of changing the way information technology infrastructure in enterprise data centers is built. Once known as a technique to achieve time sharing between processes, virtualization now offers flexibility in resource usage and software deployment, security, and energy savings by consolidation of many virtualized servers into a single physical one. However, in its modern form, virtualization is still a relatively young technology. There are many studies regarding the performance of different virtualization technologies, but only a few emphasize energy efficiency. When information technology service providers invest in more server hardware, their energy expenses also rise. As optimization for energy efficiency becomes more and more important, possible power consumption overhead caused by virtualization will be an important factor when setting up virtualized servers. In this thesis we studied virtualization using Linux with focus on energy efficiency. We conducted sets of performance tests while measuring power consumption, and assessed how virtualization affects energy efficiency. The tests included synthetic tests and more practical web server tests, with single and multiple virtual machines. We tested various configurations to find out what one should generally note when building a virtualized environment with focus on energy efficiency. All of this was done using various virtualization technologies to find out their differences regarding energy efficiency. The tested technologies were KVM, Xen, and vSphere Hypervisor. With respect to energy efficiency or performance, we observed differences in virtualization technologies, and the same technology was not always the best in every situation. We found KVM to offer good energy efficiency, and Xen to have some trouble with recent Linux versions. In web server tests, the use of paravirtualization had almost no effect on power consumption. Processor performance states affected performance and energy efficiency. Power consumption had a tendency to be generally high with bare-metal virtual machine monitors Xen and vSphere Hypervisor. More research with a wider selection of test hardware and software is required to better define the setups and situations where this power consumption trend and the possible effect of paravirtualization on energy efficiency are observable