Linux FTP Server Performance Bakeoff

ftp.cdrom.com: the current champion

How does ftp.cdrom.com do it? Their ftp server is said to be capable of handling ten thousand simultaneous downloads -- with a single CPU and network interface.

Their secret? FreeBSD and a custom ftp server daemon. It's time that Linux and its bevy of ftp servers stood up to this challenge.

The Bakeoff

I plan to compare performance of FTP daemons for Linux in a kind of performance bake-off sometime around March 2001. Each daemon will be subjected to a torture test to see how many simultaneous dialup downloads it can support. The results will be posted publicly, and I'll send the author of the winning FTP daemon a care package of homemade cookies :-) There will be separate categories for free and for commercial FTP daemons, and for "Document Tree Smaller than System RAM" and "Document Tree Larger than System RAM", so I'll be baking several batches of cookies.

Mailing List

If you're interested in participating, please join the mailing list and/or pipe up on comp.benchmarks.

Getting Your Daemon Ready

You can get ready for the bakeoff by testing your daemon yourself to see how many users it can support, eliminating bottlenecks, lowering memory consumption, and posting instructions on your daemon's support page for how to configure it and the OS to support, say, 1000 simultaneous users. The tests will probably be run with Red Hat Linux 6.2, hopefully using the 2.4 kernel.

An early version of the load generator that will be used is available now at http://www.kegel.com/dkftpbench/ You can use it now to stress-test your daemon. The load generator will be more interesting by March, but it's usable as is now.

Preliminary Results

Preliminary results with this load generator with a very small document tree show ncftpd beating out wu-ftpd and proftpd, and betaftpd whipping them all. Betaftpd won't do as well on the large document tree, though, since it will slow to a crawl as soon as it has to hit the disk.