A SOFTWARE DEFINED NETWORKING ARCHITECTURE FOR HIGH PERFORMANCE CLOUDS 1

ABSTRACT-Multi-tenant clouds with resource virtualization offer elasticity of resources and elimination of initial cluster setup cost and time for applications. However, poor network performance, performance variation and noisy neighbors are some of the challenges for execution of high performance applications on public clouds. Utilizing these virtualized resources for scientific applications, which have complex communication patterns, require low latency communication mechanisms and a rich set of communication constructs. To minimize the virtualization overhead, a novel approach for low latency networking for HPC Clouds is proposed and implemented over a multi-technology software defined network. The efficiency of the proposed low-latency SDN is analyzed and evaluated for high performance applications. The results of the experiments show that the latest Mellanox FDR InfiniBand interconnect and Mellanox OpenStack plugin gives the best performance for implementing virtual machine based high performance clouds with large message sizes

Methods and Applications of Synthetic Data Generation

The advent of data mining and machine learning has highlighted the value of large and varied sources of data, while increasing the demand for synthetic data captures the structural and statistical characteristics of the original data without revealing personal or proprietary information contained in the original dataset. In this dissertation, we use examples from original research to show that, using appropriate models and input parameters, synthetic data that mimics the characteristics of real data can be generated with sufficient rate and quality to address the volume, structural complexity, and statistical variation requirements of research and development of digital information processing systems. First, we present a progression of research studies using a variety of tools to generate synthetic network traffic patterns, enabling us to observe relationships between network latency and communication pattern benchmarks at all levels of the network stack. We then present a framework for synthesizing large scale IoT data with complex structural characteristics in a scalable extraction and synthesis framework, and demonstrate the use of generated data in the benchmarking of IoT middleware. Finally, we detail research on synthetic image generation for deep learning models using 3D modeling. We find that synthetic images can be an effective technique for augmenting limited sets of real training data, and in use cases that benefit from incremental training or model specialization, we find that pretraining on synthetic images provided a usable base model for transfer learning

Process migration in a parallel environment

To satisfy the ever increasing demand for computational resources, high performance computing systems are becoming larger and larger. Unfortunately, the tools supporting system management tasks are only slowly adapting to the increase in components in computational clusters. Virtualization provides concepts which make system management tasks easier to implement by providing more flexibility for system administrators. With the help of virtual machine migration, the point in time for certain system management tasks like hardware or software upgrades no longer depends on the usage of the physical hardware. The flexibility to migrate a running virtual machine without significant interruption to the provided service makes it possible to perform system management tasks at the optimal point in time. In most high performance computing systems, however, virtualization is still not implemented. The reason for avoiding virtualization in high performance computing is that there is still an overhead accessing the CPU and I/O devices. This overhead continually decreases and there are different kind of virtualization techniques like para-virtualization and container-based virtualization which minimize this overhead further. With the CPU being one of the primary resources in high performance computing, this work proposes to migrate processes instead of virtual machines thus avoiding any overhead. Process migration can either be seen as an extension to pre-emptive multitasking over system boundaries or as a special form of checkpointing and restarting. In the scope of this work process migration is based on checkpointing and restarting as it is already an established technique in the field of fault tolerance. From the existing checkpointing and restarting implementations, the best suited implementation for process migration purposes was selected. One of the important requirements of the checkpointing and restarting implementation is transparency. Providing transparent process migration is important enable the migration of any process without prerequisites like re-compilation or running in a specially prepared environment. With process migration based on checkpointing and restarting, the next step towards providing process migration in a high performance computing environment is to support the migration of parallel processes. Using MPI is a common method of parallelizing applications and therefore process migration has to be integrated with an MPI implementation. The previously selected checkpointing and restarting implementation was integrated in an MPI implementation, and thus enabling the migration of parallel processes. With the help of different test cases the implemented process migration was analyzed, especially in regards to the time required to migrated a process and the advantages of optimizations to reduce the process’ downtime during migration.Um die immer steigenden Anforderungen an Rechenressourcen im High Performance Computing zu erfüllen werden die eingesetzten Systeme immer größer. Die Werkzeuge, mit denen Wartungsarbeiten durchgeführt werden, passen sich nur langsam an die wachsende Größe dieser neuen Systeme an. Virtualisierung stellt Konzepte zur Verfügung, welche Systemverwaltungsaufgaben durch höhere Flexibilität vereinfachen. Mit Hilfe der Migration virtueller Maschinen können Systemverwaltungsaufgaben zu einem frei wählbaren Zeitpunkt durchgeführt werden und hängen nicht mehr von der Nutzung der physikalischen Systeme ab. Die auf der virtuellen Maschine ausgeführte Applikation kann somit ohne Unterbrechung weiterlaufen. Trotz der vielen Vorteile wird Virtualisierung in den meisten High Performance Computing Systemen noch nicht eingesetzt, dadurch Rechenzeit verloren geht und höhere Antwortzeiten beim Zugriff auf Hardware auftreten. Obwohl die Effektivität der Virtualisierungsumgebungen steigt, werden Ansätze wie Para-Virtualisierung oder Container-basierte Virtualisierung untersucht bei denen noch weniger Rechenzeit verloren geht. Da die CPU eine der zentralen Ressourcen im High Performance Computing ist wird im Rahmen dieser Arbeit der Ansatz verfolgt anstatt virtueller Maschinen nur einzelne Prozesse zu migrieren und dadurch den Verlust an Rechenzeit zu vermeiden. Prozess Migration kann einerseits als eine Erweiterung des präemptive Multitasking über Systemgrenzen, andererseits auch als eine Sonderform des Checkpointing und Restarting angesehen werden. Im Rahmen dieser Arbeit wird Prozess Migration auf der Basis von Checkpointing und Restarting durchgeführt, da es eine bereits etablierte Technologie im Umfeld der Fehlertoleranz ist. Die am besten für Prozess Migration im Rahmen dieser Arbeit geeignete Checkpointing und Restarting Implementierung wurde ausgewählt. Eines der wichtigsten Kriterien bei der Auswahl der Checkpointing und Restarting Implementierung ist die Transparenz. Nur mit einer möglichst transparenten Implementierung sind die Anforderungen an die zu migrierenden Prozesse gering und keinerlei Einschränkungen wie das Neu-Übersetzen oder eine speziell präparierte Laufzeitumgebung sind nötig. Mit einer auf Checkpointing und Restarting basierenden Prozess Migration ist der nächste Schritt parallele Prozess Migration für den Einsatz im High Performance Computing. MPI ist einer der gängigen Wege eine Applikation zu parallelisieren und deshalb muss Prozess Migration auch in eine MPI Implementation integriert werden. Die vorhergehend ausgewählte Checkpointing und Restarting Implementierung wird in einer MPI Implementierung integriert, um auf diese Weise Migration von parallelen Prozessen zu bieten. Mit Hilfe verschiedener Testfälle wurde die im Rahmen dieser Arbeit entwickelte Prozess Migration analysiert. Schwerpunkte waren dabei die Zeit, die benötigt wird um einen Prozess zu migrieren und wie sich Optimierungen zur Verkürzung der Migrationszeit auswirken

Supercomputing Frontiers

This open access book constitutes the refereed proceedings of the 6th Asian Supercomputing Conference, SCFA 2020, which was planned to be held in February 2020, but unfortunately, the physical conference was cancelled due to the COVID-19 pandemic. The 8 full papers presented in this book were carefully reviewed and selected from 22 submissions. They cover a range of topics including file systems, memory hierarchy, HPC cloud platform, container image configuration workflow, large-scale applications, and scheduling

Design and Evaluation of Low-Latency Communication Middleware on High Performance Computing Systems

[Resumen]El interés en Java para computación paralela está motivado por sus interesantes características, tales como su soporte multithread, portabilidad, facilidad de aprendizaje,alta productividad y el aumento significativo en su rendimiento omputacional. No obstante, las aplicaciones paralelas en Java carecen generalmente de mecanismos de comunicación eficientes, los cuales utilizan a menudo protocolos basados en sockets incapaces de obtener el máximo provecho de las redes de baja latencia, obstaculizando la adopción de Java en computación de altas prestaciones (High Per- formance Computing, HPC). Esta Tesis Doctoral presenta el diseño, implementación y evaluación de soluciones de comunicación en Java que superan esta limitación. En consecuencia, se desarrollaron múltiples dispositivos de comunicación a bajo nivel para paso de mensajes en Java (Message-Passing in Java, MPJ) que aprovechan al máximo el hardware de red subyacente mediante operaciones de acceso directo a memoria remota que proporcionan comunicaciones de baja latencia. También se incluye una biblioteca de paso de mensajes en Java totalmente funcional, FastMPJ, en la cual se integraron los dispositivos de comunicación. La evaluación experimental ha mostrado que las primitivas de comunicación de FastMPJ son competitivas en comparación con bibliotecas nativas, aumentando significativamente la escalabilidad de aplicaciones MPJ. Por otro lado, esta Tesis analiza el potencial de la computación en la nube (cloud computing) para HPC, donde el modelo de distribución de infraestructura como servicio (Infrastructure as a Service, IaaS) emerge como una alternativa viable a los sistemas HPC tradicionales. La evaluación del rendimiento de recursos cloud específicos para HPC del proveedor líder, Amazon EC2, ha puesto de manifiesto el impacto significativo que la virtualización impone en la red, impidiendo mover las aplicaciones intensivas en comunicaciones a la nube. La clave reside en un soporte de virtualización apropiado, como el acceso directo al hardware de red, junto con las directrices para la optimización del rendimiento sugeridas en esta Tesis.[Resumo]O interese en Java para computación paralela está motivado polas súas interesantes características, tales como o seu apoio multithread, portabilidade, facilidade de aprendizaxe, alta produtividade e o aumento signi cativo no seu rendemento computacional. No entanto, as aplicacións paralelas en Java carecen xeralmente de mecanismos de comunicación e cientes, os cales adoitan usar protocolos baseados en sockets que son incapaces de obter o máximo proveito das redes de baixa latencia, obstaculizando a adopción de Java na computación de altas prestacións (High Performance Computing, HPC). Esta Tese de Doutoramento presenta o deseño, implementaci ón e avaliación de solucións de comunicación en Java que superan esta limitación. En consecuencia, desenvolvéronse múltiples dispositivos de comunicación a baixo nivel para paso de mensaxes en Java (Message-Passing in Java, MPJ) que aproveitan ao máaximo o hardware de rede subxacente mediante operacións de acceso directo a memoria remota que proporcionan comunicacións de baixa latencia. Tamén se inclúe unha biblioteca de paso de mensaxes en Java totalmente funcional, FastMPJ, na cal foron integrados os dispositivos de comunicación. A avaliación experimental amosou que as primitivas de comunicación de FastMPJ son competitivas en comparación con bibliotecas nativas, aumentando signi cativamente a escalabilidade de aplicacións MPJ. Por outra banda, esta Tese analiza o potencial da computación na nube (cloud computing) para HPC, onde o modelo de distribución de infraestrutura como servizo (Infrastructure as a Service, IaaS) xorde como unha alternativa viable aos sistemas HPC tradicionais. A ampla avaliación do rendemento de recursos cloud específi cos para HPC do proveedor líder, Amazon EC2, puxo de manifesto o impacto signi ficativo que a virtualización impón na rede, impedindo mover as aplicacións intensivas en comunicacións á nube. A clave atópase no soporte de virtualización apropiado, como o acceso directo ao hardware de rede, xunto coas directrices para a optimización do rendemento suxeridas nesta Tese.[Abstract]The use of Java for parallel computing is becoming more promising owing to its appealing features, particularly its multithreading support, portability, easy-tolearn properties, high programming productivity and the noticeable improvement in its computational performance. However, parallel Java applications generally su er from inefficient communication middleware, most of which use socket-based protocols that are unable to take full advantage of high-speed networks, hindering the adoption of Java in the High Performance Computing (HPC) area. This PhD Thesis presents the design, development and evaluation of scalable Java communication solutions that overcome these constraints. Hence, we have implemented several lowlevel message-passing devices that fully exploit the underlying network hardware while taking advantage of Remote Direct Memory Access (RDMA) operations to provide low-latency communications. Moreover, we have developed a productionquality Java message-passing middleware, FastMPJ, in which the devices have been integrated seamlessly, thus allowing the productive development of Message-Passing in Java (MPJ) applications. The performance evaluation has shown that FastMPJ communication primitives are competitive with native message-passing libraries, improving signi cantly the scalability of MPJ applications. Furthermore, this Thesis has analyzed the potential of cloud computing towards spreading the outreach of HPC, where Infrastructure as a Service (IaaS) o erings have emerged as a feasible alternative to traditional HPC systems. Several cloud resources from the leading IaaS provider, Amazon EC2, which speci cally target HPC workloads, have been thoroughly assessed. The experimental results have shown the signi cant impact that virtualized environments still have on network performance, which hampers porting communication-intensive codes to the cloud. The key is the availability of the proper virtualization support, such as the direct access to the network hardware, along with the guidelines for performance optimization suggested in this Thesis

Towards Modern, Accessible and Dynamic HPC Using Container-based Virtual Clusters

In this thesis, a novel Virtual Container Cluster (VCC) framework is presented. Despite the growing popularity of container virtualisation in order to increase the flexi-bility of the software stack, run time environment virtualisation still poses significant portability challenges; by depending on the underlying cluster execution paradigm,a niche class of HPC only containers has emerged. This trend is detrimental to reusability, reproducibility, and encouraging new communities to HPC. Traditional virtualisation techniques have a rich history within HPC, and have been demonstrated to offer much more than software flexibility. A Virtual Machine by nature requires an OS and full stack environment akin to a physical machine, and this allows it to be instantiated regardless of the underlying machine and what services it provides. This capability is essential in order to implement job forwarding and spanning - where the burden of an entire job can be transferred or shared between hetero-geneous cluster systems - with a high level of confidence that the environments will be compatible. In turn, this brings improvements to global resource performance, reducing the job turnaround time and increasing cluster utilization. The VCC is an innovative solution that combines the full stack and container virtualisation approaches. Therefore, it offers both the flexibility of containers with the improved portability, performance and scalability of the full stack approach. In order to maintain the same accessibility and lower barrier of entry as the run time environment approach, the design incorporates an autonomous configuration and contextualisation mechanism, along with a Software Defined Networking technology, to ensure the full stack container does not place an additional burden on the user. The usefulness and performance is validated through benchmarking and two case studies: virtual clusters in the classroom and inter-institutional spanning

SInCom 2015

2nd Baden-Württemberg Center of Applied Research Symposium on Information and Communication Systems, SInCom 2015, 13. November 2015 in Konstan

System Design for Software Packet Processing

The role of software in computer networks has never been more crucial than today, with the advent of Internet-scale services and cloud computing. The trend toward software-based network dataplane—as in network function virtualization—requires software packet processing to meet challenging perfomance requirements, such as supporting exponentially increasing link bandwidth and microsecond-order latency. Many architectural aspects of existing software systems for packet processing, however, are decades old and ill-suited totoday’s network I/O workloads.In this dissertation, we explore the design space of high-performance software packet processing systems in the context of two application domains, . First, we start by discussingthe limitations of BSD Socket, which is a de-facto standard in network I/O for server applications. We quantify its performance limitations and propose a clean-slate API, called MegaPipe, as an alternative to BSD Socket. In the second part of this dissertation, we switch our focus to in-network software systems for network functions, such as network switches and middleboxes. We present Berkeley Extensible Software Switch (BESS), a modular framework for building extensible network functions. BESS introduces various novel techniques to achieve high-performance software packet processing, without compromising on either programmability or flexibility

QoS-aware architectures, technologies, and middleware for the cloud continuum

The recent trend of moving Cloud Computing capabilities to the Edge of the network is reshaping how applications and their middleware supports are designed, deployed, and operated. This new model envisions a continuum of virtual resources between the traditional cloud and the network edge, which is potentially more suitable to meet the heterogeneous Quality of Service (QoS) requirements of diverse application domains and next-generation applications. Several classes of advanced Internet of Things (IoT) applications, e.g., in the industrial manufacturing domain, are expected to serve a wide range of applications with heterogeneous QoS requirements and call for QoS management systems to guarantee/control performance indicators, even in the presence of real-world factors such as limited bandwidth and concurrent virtual resource utilization. The present dissertation proposes a comprehensive QoS-aware architecture that addresses the challenges of integrating cloud infrastructure with edge nodes in IoT applications. The architecture provides end-to-end QoS support by incorporating several components for managing physical and virtual resources. The proposed architecture features: i) a multilevel middleware for resolving the convergence between Operational Technology (OT) and Information Technology (IT), ii) an end-to-end QoS management approach compliant with the Time-Sensitive Networking (TSN) standard, iii) new approaches for virtualized network environments, such as running TSN-based applications under Ultra-low Latency (ULL) constraints in virtual and 5G environments, and iv) an accelerated and deterministic container overlay network architecture. Additionally, the QoS-aware architecture includes two novel middlewares: i) a middleware that transparently integrates multiple acceleration technologies in heterogeneous Edge contexts and ii) a QoS-aware middleware for Serverless platforms that leverages coordination of various QoS mechanisms and virtualized Function-as-a-Service (FaaS) invocation stack to manage end-to-end QoS metrics. Finally, all architecture components were tested and evaluated by leveraging realistic testbeds, demonstrating the efficacy of the proposed solutions