In this body of work, we present the details of a novel method for passive resource discovery in cluster grid environments where resources constantly utilize inter-node communication. Our method offers the ability to non-intrusively identify resources that have available memory or CPU cycles; this is critical for lowering queue wait times in large cluster grid networks, and for memory-intensive cluster grid applica-tions such as Gaussian (computational chemistry package) and the Weather Research and Forecasting (WRF) modeling package. The benefits include: (1) low message complexity, (2) scalability, (3) load bal-ancing support, and (4) low maintainability. Using several test-beds (i.e., a small local test-bed and a 50-node Deterlab test-bed), we demonstrate the feasibility of our method with experiments utilizing TCP, UDP and ICMP network traffic. Using this technique, we observed a correlation between memory or CPU load and the timely response of network traffic. In such situations, we have observed that in highly utilized (due to multi-programming) nodes there will be numerous, active processes which require context switching or paging. The latency associated with numerous context switches or paging manifests as a de-lay signature within the packet transmission process. Our method detects this delay signature to determine the utilization of network resources. The aforementioned delay signature is the keystone that provides a correlation between network traffic and the internal state of the source node. We characterize this delay signature due to CPU utilization by (1) identifying the different types of assembly language instructions that source this delay and (2) describing how performance-enhancing techniques (e.g., instruction pipelin-ing, caching) impact this delay signature by using the LEON3, implemented as a 40 MHz development board. At the software level, results for medium sized networks show that our method can consistently and accurately identify nodes with available memory or CPU cycles (< 70% availability). At the hardware level, our results show that excessive context switching in active applications increases the average mem-ory access time, thus adding additional delay to the execution of LD instructions. Additionally, internal use of these instructions in heavily utilized situations to send network packets induces the delay signature into network traffic.

Diplomarbeit im Schnittgebiet von Cluster- und Grid-Computing. Einbindung verteilter Ressourcen in eine Infrastruktur. Realisierung einer einfachen Checkpointing-Umgebung.

No description available.

An increased need for collaborative research among different organizations, together with continuing advances in communication technology and computer hardware, has facilitated the development of distributed systems that can provide users non-trivial access to geographically dispersed computing resources (processors, storage, applications, data, instruments, etc.) that are administered in multiple computer domains. The term grid computing or grids is popularly used to refer to such distributed systems. A broader definition of grid computing includes the use of computing resources within an organization for running organization-specific applications. This research is in the context of using grid computing within an enterprise to maximize the use of available hardware and software resources for processing enterprise applications. Large scale scientific simulations have traditionally been the primary benefactor of grid computing. The application of this technology to simulation in industry has, however, been negligible. This research investigates how grid technology can be effectively exploited by simulation practitioners using Windows-based commercially available simulation packages to model simulations in industry. These packages are commonly referred to as Commercial Off-The-Shelf (COTS) Simulation Packages (CSPs). The study identifies several higher level grid services that could be potentially used to support the practise of simulation in industry. It proposes a grid computing framework to investigate these services in the context of CSP-based simulations. This framework is called the CSP-Grid Computing (CSP-GC) Framework. Each identified higher level grid service in this framework is referred to as a CSP-specific service. A total of six case studies are presented to experimentally evaluate how grid computing technologies can be used together with unmodified simulation packages to support some of the CSP-specific services. The contribution of this thesis is the CSP-GC framework that identifies how simulation practise in industry may benefit from the use of grid technology. A further contribution is the recognition of specific grid computing software (grid middleware) that can possibly be used together with existing CSPs to provide grid support. With its focus on end-users and end-user tools, it is intended that this research will encourage wider adoption of grid computing in the workplace and that simulation users will derive benefit from using this technology.

A fundamental problem in building large scale Grid resource sharing system is the need for efficient and scalable techniques for discovery and provisioning of resources for delivering expected Quality of Service (QoS) to users’ applications. The current approaches to Grid resource sharing based on resource brokers are non-coordinated since these brokers make scheduling related decisions independent of the others in the system. Clearly, this worsens the load-sharing and utilisation problems of distributed Grid resources as sub-optimal schedules are likely to occur. Further, existing brokering systems rely on centralised information services for resource discovery. Centralised or hierarchical resource discovery systems are prone to single-point failure, lack scalability and fault-tolerance ability. In the centralised model, the network links leading to the server are very critical to the overall functionality of the system, as their failure might halt the entire distributed system operation.

The next generation of scientific experiments and studies are being carried out by large collaborations of researchers distributed around the world engaged in analysis of huge collections of data generated by scientific instruments. Grid computing has emerged as an enabler for such collaborations as it aids communities in sharing resources to achieve common objectives. Data Grids provide services for accessing, replicating and managing data collections in these collaborations. Applications used in such Grids are distributed data-intensive, that is, they access and process distributed datasets to generate results. These applications need to transparently and efficiently access distributed data and computational resources. This thesis investigates properties of data-intensive computing environments and presents a software framework and algorithms for mapping distributed data-oriented applications to Grid resources. (For complete abstract open document)

Zugl.: München, Techn. Univ., Diss., 2008

Zugl.: Siegen, Univ., Diss., 2009

O objetivo do trabalho é a implementação de características de adaptabilidade ao VIC, software livre de videoconferência sobre multicast. O VIC é um software para vídeo utilizado pelos principais frameworks de videoconferência em uso no mundo. O trabalho é focado em cima do VIC para o Access Grid, desenvolvido no Argone National Laboratory. Videoconferência é uma aplicação que consome muitos recursos da rede e do processamento da máquina, devido à grande quantidade de informações com que trabalha e à velocidade com que estas informações devem ser processadas e transmitidas. Pelas próprias características intrínsecas de uma transmissão de vídeo, não são admitidos atrasos. O trabalho analisa as principais tecnologias e o estado da arte em videoconferência, tanto na parte de transmissão quanto na parte de codificação e decodificação de sinais. As principais ferramentas em uso são apresentadas com suas características próprias. Os dois principais enfoques de adaptabilidade para transmissão e recepção de vídeo são expostos. O trabalho propõe um modelo misto, baseado nestes dois enfoques. A partir daí é exposto o novo algoritmo criado e os resultados de alguns testes realizados. Até hoje, apenas uma tentativa foi feita de acrescentar características de adaptabilidade à condição da rede ao VIC, porém essa não se encontra em uso. O trabalho propõe um novo algoritmo de adaptabilidade utilizando características das duas principais tendências atualmente em pesquisa. / The goal of the work is to implement adaptability features to VIC, free software to deliver videoconferencing over multicast. VIC is a software to transmit video used by the main videoconferencing frameworks in use worldwide. The focus of the work is on VIC to Access Grid, developed at Argone National Laboratory. Videoconferencing is an application that uses too much resources of the network and processing power of the machine, due to the huge amount of information that it handles and due to the speed needed to process and transmit this information. For its own intrinsic properties, delays are not allowed in videoconferencing. The work analyses the main technologies and the state of the art in videoconferencing, both in transmission and in encoding and decoding of signals. The main tools in use are presented with their own characteristics. The two main approaches of adaptability for video transmission and reception are shown. The work proposes a new model, based on both approaches in a mixed way. The new algorithm created is shown together with the results of some tests made. Until today, only one try was made to add adaptability to the network conditions to VIC, but it is not in use. The work proposes a new adaptability algorithm using features of the two main trends in research today.

O objetivo do trabalho é a implementação de características de adaptabilidade ao VIC, software livre de videoconferência sobre multicast. O VIC é um software para vídeo utilizado pelos principais frameworks de videoconferência em uso no mundo. O trabalho é focado em cima do VIC para o Access Grid, desenvolvido no Argone National Laboratory. Videoconferência é uma aplicação que consome muitos recursos da rede e do processamento da máquina, devido à grande quantidade de informações com que trabalha e à velocidade com que estas informações devem ser processadas e transmitidas. Pelas próprias características intrínsecas de uma transmissão de vídeo, não são admitidos atrasos. O trabalho analisa as principais tecnologias e o estado da arte em videoconferência, tanto na parte de transmissão quanto na parte de codificação e decodificação de sinais. As principais ferramentas em uso são apresentadas com suas características próprias. Os dois principais enfoques de adaptabilidade para transmissão e recepção de vídeo são expostos. O trabalho propõe um modelo misto, baseado nestes dois enfoques. A partir daí é exposto o novo algoritmo criado e os resultados de alguns testes realizados. Até hoje, apenas uma tentativa foi feita de acrescentar características de adaptabilidade à condição da rede ao VIC, porém essa não se encontra em uso. O trabalho propõe um novo algoritmo de adaptabilidade utilizando características das duas principais tendências atualmente em pesquisa. / The goal of the work is to implement adaptability features to VIC, free software to deliver videoconferencing over multicast. VIC is a software to transmit video used by the main videoconferencing frameworks in use worldwide. The focus of the work is on VIC to Access Grid, developed at Argone National Laboratory. Videoconferencing is an application that uses too much resources of the network and processing power of the machine, due to the huge amount of information that it handles and due to the speed needed to process and transmit this information. For its own intrinsic properties, delays are not allowed in videoconferencing. The work analyses the main technologies and the state of the art in videoconferencing, both in transmission and in encoding and decoding of signals. The main tools in use are presented with their own characteristics. The two main approaches of adaptability for video transmission and reception are shown. The work proposes a new model, based on both approaches in a mixed way. The new algorithm created is shown together with the results of some tests made. Until today, only one try was made to add adaptability to the network conditions to VIC, but it is not in use. The work proposes a new adaptability algorithm using features of the two main trends in research today.