Damelo! A Specialized Web Cache File System
by Jonathan Ledlie and Remzi H. Arpaci-Dusseau
The Damelo file system provides specialized high speed file access
to web object caching applications. For typical static web object
workloads, file operations (create, read, delete) execute
significantly faster than on a comparable file system, Linux's ext2.
Instead of grouping files into directories, Damelo offers a new
interface which grants fine grained control over on-disk adjacency.
This grouping mechanism prefetches related files, enabling the first
cache hit for an object to absorb the I/O cost for the rest of its
group. File access microbenchmarks compare Damelo with ext2.
A simple file cache using Damelo compares favorably with Squid, a
commonly used file cache, achieving 617 versus 545 requests per second,
respectively.