Using zsync for .deb downloads: initial benchmark results

[Lars Wirzenius]

ti, 2009-07-14 kello 20:25 +0200, Martin Pitt kirjoitti:
> Just to be completely sure that I understood this correctly: if I have
> package foo 5ubuntu1, and then a security update (which changes two
> lines of code) 5ubuntu2 comes along, then I need to download 75%
> of 5ubuntu2 with zsync'ing against -5ubuntu1?

Correct.

> Any idea why this is so bad? rsync has an intelligent server and thus
> can do very fine grained blocking. Perhaps zsync, being limited by
> HTTP, tries to weigh round trips against block size, or something like
> that?

I don't know why zsync performs so badly in my tests. I've tried
different block sizes and quite small block sizes (say, 128 bytes) do
give better results (from 25% saved up to 35% saved), but then
the .zsync files grow a lot bigger, too, so it's not really worth it.