PDL Abstract

Consistency-preserving Caching of Dynamic Database Content

International World Wide Web Conference (WWW 2007), May 8-12, 2007, Banff, Alberta, Canada.

Niraj Tolia and M. Satyanarayanan

School of Computer Science & Electrical and Computer Engineering
Carnegie Mellon University
Pittsburgh, PA 15213


With the growing use of dynamic web content generated from relational databases, traditional caching solutions for throughput and latency improvements are ineffective. We describe a middleware layer called Ganesh that reduces the volume of data transmitted without semantic interpretation of queries or results. It achieves this reduction through the use of cryptographic hashing to detect similarities with previous results. These benefits do not require any compromise of the strict consistency semantics provided by the back-end database. Further, Ganesh does not require modifications to applications, web servers, or database servers, and works with closed-source applications and databases. Using two benchmarks representative of dynamic web sites, measurements of our prototype show that it can increase end-to-end throughput by as much as twofold for non-data intensive applications and by as much as tenfold for data intensive ones.

KEYWORDS: content addressable storage, relational database systems, database caching, wide area networks, bandwidth optimization