<title>Resource-based caching for Web servers</title>

Abstract

The WWW employs a hierarchical data dissemination architecture in which hyper-media objects stored at a remote server are served to clients across the Internet, and cached on disks at intermediate proxy servers. One of the objectives of web caching algorithms is to maximize the data transferred from the proxy servers or cache hierarchies. Current web caching algorithms are designed only for text and image data. Recent studies predict that within the next five years more than half the objects stored at web servers will contain continuous media data. To support these trends, the next generation proxy cache algorithms will need to handle multiple data types, each with different cache resource usage, for a cache limited by both bandwidth and space. In this paper, we present a resource-based caching (RBC) algorithm that manages the heterogeneous requirements of multiple data types. The RBC algorithm (1) characterizes each object by its resource requirement and a caching gain, (2) dynamically selects the granularity of the entity to be cached that minimally uses the limited cache resource (i.e., bandwidth or space), and (3) if required, replaces the cached entities based on their cache resource usage and caching gain. We have performed extensive simulations to evaluate our caching algorithm and present simulation results that show that RBC outperforms other known caching algorithms.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.