OurGrid

Abstract: Access control to resources is one of the most important requirements to be satisfied in grid systems that span over multiple administrative domains. Such a mechanism allows every institution taking part of a grid community to define and enforce policies for the use of their local resources by remote users. Despite the efforts of the research community to address this topic, existing approaches do not scale (e.g., in terms of communication overhead) for a large number of nodes (peers) providing resources, as these approaches rely on centralized servers to process access requests. Furthermore, they provide limited, large-grain policy specification functionality and are not committed to employing open, standardized formats to express policies. In this paper, we address these limitations by proposing PeGAC (peer-to-peer grid access control), a policy-based, distributed access control mechanism, which can be applied to P2P grid systems. In our proposal, policies are specified using the role-based access control model and coded using the extensible access control markup language. As a proof-of-concept we have integrated PeGAC into OurGrid, a middleware for the implementation of P2P grid systems. Preliminary results of experiments carried out at the resulting infrastructure show that our solution poses small communication and processing overhead, and can handle large policy repositories efficiently.

Abstract: The dynamic, multi-organization nature of large-scale grid computing introduces security issues that must be addressed before grid systems can become widely popular. This paper proposes P2PSLF (Peer-to-Peer Security Layer Framework), a flexible security framework for peer-to-peer based grid computing. P2PSLF provides a wide range of security mechanisms (e.g., authentication, confidentiality, integrity, authorization, and audit), and allows the creation of new ones. It is independent of the overlying application, which enables new systems to be implemented without having to deal with security issues within the application. In addition, the framework is modular and reconfigurable. The set of security requirements to be satisfied in communications is determined per peer, and can be changed without recompiling the application. The framework is exercised using OurGrid, a P2P-based middleware that enables the creation of a multi-organization grid computing environment for the execution of bag-of-tasks applications.

Abstract: Peer-to-Peer (P2P) Desktop Grids are computing infrastructures that aggregate a set of desktop-class machines in which all the participating entities have the same roles, responsibilities, and rights. In this paper, we present ShareGrid, a P2P Desktop Grid infrastructure based on the OurGrid middleware, that federates the resources provided by a set of small research laboratories to easily share and use their computing resources. We discuss the techniques and tools we employed to ensure scalability, efficiency, and usability, and describe the various applications used on it. We also demonstrate the ability of ShareGrid of providing good performance and scalability by reporting the results of experimental evaluations carried out by running various applications with different resource requirements. Our experience with ShareGrid indicates that P2P Desktop Grids can represent an effective answer to the computing needs of small research laboratories, as long as they provide both ease of management and use, and good scalability and performance.