The grid vision of a single computing utility has yet to materíalize: while many grids with thousands of processors each exist, most work in isolation. An important obstacle for the effective and efficient inter-operation of grids is the problem of resource selection. In this paper we propose a solution to this problem that combines the hierarchical and decentralized approaches for interconnecting grids. In our solution, a hierarchy of grid sites is augmented with peer-to-peer connections between sites under the same administrative control. To operate this architecture, we employ the key concept of delegated matchmaking, which temporarily binds resources from remote sites to the local environment. With trace-based simulations we evaluate our solution under various infrastructural and load conditions, and we show that it outperforms other approaches to inter-operating grids. Specifically, we show that delegated matchmaking achieves up to 60% more goodput and completes 26% more jobs than its best alternative.

Firewalls/NATs have brought significant connectivity problems along with their benefits, causing many applications to break or become inefficient. Due to its bi-directional communication, huge scale, and multi-organizational nature, the grid may be one of the areas damaged most by the connectivity problem. Several ideas to deal with the connectivity problem were investigated and many systems are available. However, many issues still remain unanswered. Most systems are firewall/NAT unfriendly and are considered harmful to network security; the tussle between these devices trying to investigate pay loads and applications trying to protect their content from observation and modification must be reconciled. This paper discusses how a simple relay-based system, called XRAY (middlebox traversal by relaying), deals with these issues and provides other benefits such as flexible traffic control. This paper also discusses how relay-based traversal systems can help applications to communicate over firewalls/NATs and also complement firewall/NAT operations to help network security

This work describes an approach to building Grid applications based on the premise that users who wish to access and run these applications prefer to do so without becoming experts on Grid technology. We describe an application architecture based on wrapping user applications and application workflows as Web services and Web service resources. These services are visible to the users and to resource providers through a family of Grid portal components that can be used to configure, launch, and monitor complex applications in the scientific language of the end user. The applications in this model are instantiated by an application factory service. The layered design of the architecture makes it possible for an expert to configure an application factory service with a custom user interface client that may be dynamically loaded into the portal.