Towards an Accounting System for Multi-Provider Grid Environments

As of today, grids provide the technology, applications, and platforms for a seamless access to resources, services, and content in a fully decentralized world of distributed information, computing power, and information technology business. Grid systems have evolved over time from pure computational grids to service grids and therefore provide a sustainable platform for electronic service provisioning in research-oriented and commercial multi-domain environments. Dealing with complex virtual services and virtual resources where service compositions have to take place on-demand, for certain periods of time, and across organizational boundaries imposes new challenging requirements to the underlying accounting system. The paper proposes an accounting system for complex virtual services and resources in grid environments based on (i) a service model for dynamic virtual organizations, overcoming the typically static nature of traditional grids, and (ii) a detailed description of a job workflow, in order to identify accounting relevant components and interfaces within a virtual organization. Based on the insights gained, a concept is proposed to derive accounting records, documenting the usage of virtual services and resources, out of the various data sources. Since virtual services and resources are provided by several providers (real or virtual organizations), the complexity of this task is obvious. An assessment, of the proposed system is done through a prototypical implementation based upon specific data from grid middlewares such as the Globus toolkit.