Load and traffic balancing in large scale cache meshes

The current document summarizes the experiences obtained during the maintenance and operations of the cache hierarchy within the German broadband research network. Installed at central nodes, the cache service is an integral part of the backbone infrastructure. Ten distributed cache servers are the building blocks of a large scale top-level cache hierarchy. Since the beginning in January 1997, the DFN cache service was subjected to different mesh designs and conceptions. Various approaches were aimed at improvements in the load and traffic balance among the caches. At the same time, the benefit of the mesh as whole was to be increased, as well. Due to the fact that the caches are used in a production-like environment, few of the variations thought of manifested themselves in practical configurations. Maintainers of similar cache meshes may benefit from our ideas and experiences related in this document for their own conceptual design, configuration, and hardware selection. The reader might want to investigate further publications describing the design of single web caching systems [1-4]. (C) 1998 Elsevier Science B.V. All rights reserved.