Hummingbird: A light-weight file system for caching web proxies
Eran Gabber eran@bell-labs.com
Elizabeth Shriver shriver@bell-labs.com
Christopher Stein stein@eecs.harvard.edu
abstract Today, caching web proxies use general purpose file systems to store information that does not fit into main memory. Proxies such as Squid or Apache, when running on a UNIX system, typically use some derivative of the 4.2BSD Fast File System (FFS) for this purpose. FFS was designed 15 years ago for workload demands and requirements very different from that of a caching web proxy. Some of the differences are high temporal locality, relaxed persistence and a different read/write ratio. In this paper, we characterize the web proxy workload, describe the design of Hummingbird, a light-weight file system for web proxies, and present preliminary trace-driven performance measurements of Hummingbird. Our results indicate that Hummingbird's throughput is 7-8 times larger than a simulated version of Squid running on XFS, a high performance UNIX file system.