Felix Freitag

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Application-layer networks (ALN) are software architectures that allow the provisioning of services requiring a huge amount of resources by connecting large numbers of individual computers. The ALN simulation project CATNET evaluates a decentralized mechanism for resource allocation in ALN, which is based on the economic paradigm of the Catallaxy, against a(More)
Efficient resource allocation in dynamic large-scale environments is one of the challenges of Grids. In centralized economic-based allocation approaches, the user requests can be matched to the fastest, cheapest or most available resource. This approach, however, shows limitations in scalability and in dynamic environments. In this paper, we explore a(More)
Application layer networks are software architectures that allow the provisioning of services requiring a huge amount of resources by connecting large numbers of individual computers like in Grid or Peer to Peer computing Controlling the resource allocation in those net works is nearly impossible using a centralized arbitrator The network simulation project(More)
Application-layer networks (ALN) are software architectures that allow the provisioning of services requiring a huge amount of resources by connecting large numbers of individual computers, e.g. Grids and P2PNetworks. Self-organization, like proposed by the Autonomic Computing concept, might be the key to controlling these systems. The CATNET project(More)
Grid computing has recently become an important paradigm for managing computationally demanding applications (composed of a collection of services). Providing dynamic discovery of services, and the determination of a service with the “best value” remains a complex problem in Grid computing. Such a decision is a multi-attribute n : m allocation problem, and(More)
In a market, information about its specifications and the behavior of its participants is essential for sophisticated and efficient negotiation strategies. However, there is currently no completely researched system to provide and consult an overall knowledge of economic information in distributed markets. These markets are implemented for example by grid(More)
Scalability to large number of processes is one of the weaknesses of current MPI implementations. Standard implementations are able to scale to hundreds of nodes, but no beyond that. The main problem of current implementations is that performance is more important than scalability and thus some assumptions about resources are taken that will not scale well.(More)
A powerful and widely-used method for analyzing the performance behavior of parallel programs is event tracing. When an application is traced, performancerelevant events, such as entering functions or sending messages, are recorded at runtime and analyzed post-mortem to identify and potentially remove performance problems. While event tracing enables the(More)
The expression “crowdsourced computer networks” refers to a network infrastructure built by citizens and organisations who pool their resources and coordinate their efforts to make these networks happen. “Community networks” are a subset of crowdsourced networks that are structured to be open, free, and neutral. In these communities the infrastructure is(More)
In this paper we describe an application deployment using a Catallactic Grid-enabled middleware, which is based on the Catallaxy "free market" self-organisation approach described by von Hayek [7], who understood the market as a decentralised coordination mechanism opposite to a centralised command economy. The implementation makes use of Globus Toolkit,(More)