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Scalable Monitoring System for Clouds

Although cloud computing has become an important topic over the last couple of years, the development of cloud-specific monitoring systems has been neglected. This is surprising considering their importance for metering services and, thus, being able to charge customers. In this paper we introduce a monitoring architecture that was developed and is currently implemented in the EASI-CLOUDS project. The demands on cloud monitoring systems are manifold. Regular checks of the SLAs and the precise billing of the resource usage, for instance, require the collection and converting of infrastructure readings in short intervals. To ensure the scalability of the whole cloud, the monitoring system must scale well without wasting resources. In our approach, the monitoring data is therefore organized in a distributed and easily scalable tree structure and it is based on the Device Management Specification of the OMA and the DMT Admin Specification of the OSGi. Its core component includes the interface, the root of the tree and extension points for sub trees which are implemented and locally managed by the data suppliers themselves. In spite of the variety and the distribution of the data, their access is generic and location-transparent. Besides simple suppliers of monitoring data, we outline a component that provides the means for storing and preprocessing data. The motivation for this component is that the monitoring system can be adjusted to its subscribers - while it usually is the other way round. In EASI-CLOUDS, the so-called Context Stores aggregate and prepare data for billing and other cloud components.