Query Affinity in Internet Applications
Report ID: TR-621-00Author: Chen, Mao / Ji, Minwen / Felten, Edward W. / Singh, Jaswinder Pal
Date: 2000-12-00
Pages: 10
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Abstract:
We investigate how to improve the price-performance of Internet application servers by caching their dynamic content in a cluster of cache servers. In particular, we study distribution strategies that automatically and dynamically partition and replicate data across individual cache servers and directs queries to the right servers, in order to maximize effective cache capacity and minimize synchronization cost. Despite the conflicts in partitioning dynamic content, we observe natural query affinity in a wide range of Internet applications, which could be exploited in distribution strategies. We have designed an affinity-based distribution (ABD) strategy for a cluster of cache servers. We evaluate the distribution strategy with a set of trace-based simulations. The results show that ABD reduces cache miss ratio by a factor of 1.7 to 9 over alternative strategies. The results also indicate that application servers, especially those that update their back-end databases, have a higher demand for good distribution strategies than static web servers.