Numerous studies show that proxy cache miss ratios are typically at least 40\%-50\%. This paper proposes and evaluates a new approach for improving the throughput of proxy caches by reducing cache miss overheads. An embedded system able to achieve significantly better communications performance than a traditional proxy filters the requests directed to a proxy cache, forwarding the hits to the proxy and processing the misses itself. This system, which we call a proxy accelerator, uses hints of the proxy cache content and may include a main memory cache for the hottest objects. Scalability with the Web proxy cluster size is achieved by using several accelerators. We use analytical models and trace-based simulations to study the benefits of this scheme and the potential impacts of hint-related mechanisms. Our proxy accelerator results in significant performance improvements. A single proxy accelerator node in front of a four-node Web proxy improves throughput by about 100\%.
By: Daniela Rosu, Arun Iyengar, Daniel Dias
Published in: RC21611 in 1999
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