Some unscientific timing results (on the Python source tree)

[John Arbash Meinel]

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Toshio Kuratomi wrote:
| Talden wrote:
|> I still don't believe that the majority of uses to which Bazaar is put
|> would likely produce enough simultaneous activity to swamp servers yet
|> slow streaming affects nearly everyone.  Making compressed streaming
|> the default and providing a tuning switch for others seems a better
|> choice if we're trying to work the best we can out of the box for most
|> users.
|>
| There are other choices than streaming on or streaming off, though.  For
| instance, you could compress deltas ahead of time.  I'm not a Core dev
| so I don't have to make choices about the tradeoffs involved here :-)
| but I want to let people know that there are sourceforge-like setups
| where having to choose between on the fly bz2 compression or no
| compression would both be bad options.

You can, but the big benefit is cross-delta compression. The deltas themselves
are small enough that you don't gain a lot.

It also adds load to the client, as you then have to 'bzip2 -d' split up by
hunks and then gzip the hunks.

Certainly that is something like zsync versus rsync. (afaik, zsync is rsync with
pre-computed checksums on the server.)

There is also the question of whether on local networks the computation overhead
is actually slower (in real-time components) than streaming a bit more data.

So you certainly end up with a bit of "it works better in this one case, but in
these 3 it is worse". It doesn't mean we won't do it, just that we aren't
strictly concerned about a single benchmark.

|
| Before gnome.org switched to svn they had a request for devs to use cvs
| -z3 instead of -z9 since that was judged to be the sweet spot in
| compression vs CPU usage.
|
| -Toshio
|

John
=:->
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