Wolfgang Ziegler

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We present fundamental challenges for scalable and dependable service platforms and architectures that enable flexible and dynamic provisioning of cloud services. Our findings are incorporated in a toolkit targeting the cloud service and infrastructure providers. The innovations behind the toolkit are aimed at optimizing the whole service life cycle,(More)
The Grid paradigm implies the sharing of a variety of resources across multiple administrative domains. In order to execute a work-flow using these distributed resources an instrument is needed to co-allocate resources by reaching agreements with the different local scheduling systems involved. Apart from compute resources to execute the work-flow the(More)
UNICORE is a European Grid Technology with more than 10 years of history. Originating from the Supercomputing domain, the latest version UNICORE 6 has turned into a general-purpose Grid technology that follows established standards and offers a rich set of features to its users. The paper starts with an architectural insight into UNICORE 6, highlighting the(More)
Thank you very much for downloading low power variation tolerant design in nanometer silicon. As you may know, people have search hundreds times for their favorite readings like this low power variation tolerant design in nanometer silicon, but end up in malicious downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they(More)
The Web Services Agreement specification defines a normative language to formulate Service Level Agreements and a basic protocol to expose service-level descriptions, validate service-level requests, and come to an agreement. This protocol, often called “take-it-or-leave-it”, allows a service provider and a service consumer to decide whether(More)
A typical task of a grid level scheduling service is the orchestration and coordination of resources in the grid. Especially the co-allocation of resources makes high demands on this service. Co-allocation requires the grid level scheduler to coordinate resource management systems located in different domains. Provided that the site autonomy has to be(More)
The definition of a generic Grid scheduling architecture is the concern of both the Open Grid Forum’s Grid Scheduling Architecture Research Group and a CoreGRID research group of the same name. Such an architecture should provide a blueprint for Grid system and middleware designers and assist them in linking their scheduling requirements to diverse existing(More)
Service Level Agreements may be used to establish agreements on the quality of a service between a service provider and a service consumer. The roles of service provider and service consumer may realised in different shapes ranging from individuals to institutions, software agents or other systems acting on behalf of physical entities or steered by those.(More)
Coordinated usage of resources in a Grid environment is a challenging task impeded by the nature of resource usage and provision: Resources reside in different geographic locations, are managed by different organisations, and the provision of reliable access to these resource usually has to be negotiated and agreed upon in advance. These prerequisites have(More)
Running large MPI-applications with resource demands exceeding the local site’s cluster capacity could be distributed across a number of clusters in a Grid instead, to satisfy the demand. However, there are a number of drawbacks limiting the applicability of this approach: communication paths between compute nodes of different clusters usually provide lower(More)