A model for usage policy-based resource allocation in grids

Challenging usage policy issues can arise within virtual organizations (VOs) that integrate participants and resources spanning multiple physical institutions. Participants may wish to delegate to one or more VOs the right to use certain resources subject to local policy and service level agreements; each VO then wishes to use those resources subject to VO policy. How are such local and VO policies to be expressed, discovered, interpreted, and enforced? As a first step to addressing these questions, we develop and evaluate policy management solutions within a specialized context, namely scientific data grids within which the resources to be shared are computers and storage. We propose an architecture and recursive policy model, and define roles and functions, for scheduling resources in grid environments while satisfying resource owner and VO policies.

1. Introduction

We consider scenarios in which providers wish to grant to consumers the right to use certain resources for some agreed-upon time period. Providers might be companies providing outsourcing services, or scientific laboratories that provide different collaborations with access to their computing resources. Providers and consumers may be nested: a provider may function as a middleman, providing access to resources to which the provider has itself been granted access by some other provider. Usage policy issues can arise at multiple levels in such scenarios. Providers want to express (and enforce) the policies under which resources are made available to consumers. Consumers want to access and interpret policy statements published by providers, in order to monitor their agreements and guide their activities. Both providers and consumers want to verify that policies are applied correctly. In summary, we are interested in the expression, publication, discovery, enforcement, and verification of policies, at both resource provider and consumer levels.