Enforcing Resource Sharing Agreements among Distributed Server Clusters

Future scalable, high throughput, and high performance applications are likely to execute on platforms constructed by clustering multiple autonomous distributed servers, with resource access governed by agreements between the owners and users of these servers. As an example, application service providers (ASPs) can pool their resources together according to pre-specified sharing agreements to provide better services to their customers. Such systems raise several new resource management challenges, chief amongst which is the enforcement of agreements to ensure that, despite the distributed nature of both requests and resources, user requests only receive a predetermined share of the aggregate resource and that the resources of a participant are not misused. Current solutions only enforce such agreements at a coarse granularity and in a centralized fashion, limiting their applicability for general workloads. This paper presents an architecture for the distributed enforcement of resource sharing agreements. Our approach exploits a uniform application-independent representation of agreements, and combines it with efficient time-window based coordinated queuing algorithms running on multiple nodes. We have successfully implemented this general strategy in two different network layers: a layer-7 HTTP redirector and a layer-4 packet redirector, which redirect connection requests from distributed clients to a cluster of distributed servers. Our measurements of both implementations verify that our approach is general and effective: different client groups receive service commensurate with their agreements.