Hummingbird: A light-weight file system for caching web proxies
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 derivativeof the 4.2BSD Fast File System (FFS) for this purpose. FFS was designed15 years ago for workload demands and requirements very different fromthat of a caching web proxy. Some of the differences are high tempora locality, relaxed persistence and a different read/write ratio. In this talk, I will 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. Example results indicate that Hummingbird's throughput is 2-5 times larger than a simulated version of Squid running on XFS, a high performance UNIX file system. This is joint work with Eran Gabber, Christopher Stein, and Lan Huang.