Re: Official Git mirror?

[Eli Zaretskii <eliz@gnu.org>]

> From: Óscar Fuentes <ofv@wanadoo.es>
> Date: Mon, 21 Feb 2011 20:40:37 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> It seems that "nosmart" is used for compensating for servers with busy
> >> CPUs
> >
> > No, it's used to compensate for overly "smart" server when there's no
> > win in being smart, because you need to send everything anyway.
> 
> But then the plan is failing, because the timings I posted show that
> "smart" wins over "nosmart" even when a weak server is servicing a
> mighty client over a fast network.

Sometimes it indeed makes no significant difference, but sometimes it
wins big time.  Observe:

 bzr://bzr.savannah.gnu.org/emacs/trunk

    real    45m4.820s
    user    15m58.380s
    sys     0m12.910s

    Transferred: 540480KiB (199.9K/s r:540403K w:77K)

  bzr branch nosmart+bzr://bzr.savannah.gnu.org/emacs/trunk


    real    16m30.189s
    user    15m22.090s
    sys     0m14.560s

    Transferred: 780914KiB (789.2K/s r:780640K w:275K)

In the thread I mentioned on the Bazaar list, someone else also
reported a huge speedup:

> over a 3 Mbit/s connection:
> 
>    bzr://bzr.savannah.gnu.org/emacs/trunk
>    6949.356  Transferred: 469739kB (67.6kB/s r:469659kB w:80kB)
> 
>    nosmart+bzr://bzr.savannah.gnu.org/emacs/trunk
>    2919.117  Transferred: 524353kB (179.7kB/s r:524162kB w:191kB)

That's almost 2 hours slashed to 48 minutes, an almost 3-fold speedup.

> > The "smart" part is for sending less data, which is not going to win
> > for the initial checkout.
> 
> You said on the other post that cloning time is network-bound. So being
> smart and sending less data would be better.

Not if "being smart" wastes CPU cycles on the server side and causes
it to use the available bandwidth less efficiently.  See the network
throughput figures above, reported by bzr on .bzr.log.