Look ma, the kernel don't compile no more...

Ken Smith kensmith at cse.Buffalo.EDU
Sat Jan 10 10:19:32 PST 2004


On Sat, Jan 10, 2004 at 11:06:58AM -0600, Kirk Strauser wrote:

> Out of curiosity, why would multiple syncs be better than just one?
> Wouldn't the final sync be the same whether you'd done several before it or
> not?

It all depends on where you're sync-ing from.  Keep in mind the
cvsup mirror sites are exactly that - mirrors.  There is one
central CVS repository.  If a developer is doing an update of the
main CVS repository as several commits there can be several minutes'
worth of time that what's in the CVS repository is "inconsistent"
because what s/he committed first contains things that depend on
things that s/he commits a little bit later (composing log messages
can take time, etc.).

cvsup-master itself mirrors from the main CVS repository roughly
every 10 minutes I think.  So if it takes a snapshot between the
developer's first and second commit and if you're using cvsup-master
as where you sync from then doing two sync's 10 to 20 minutes apart
can help with this sort of problem if you watch what gets updated
to watch for stuff that "seems related".

Virtually every other public cvsup mirror site will be mirroring
from cvsup-master, but typically with about an hour between syncs.

There are things that can make things a little bit more complicated
than this.  For example last night's 5.2-RELEASE tag touches a huge
number of files.  cvsup-master's load was around 50 for a while, and
it took one machine I was watching over an hour to do the first sync
after the tagging.  A mirror site won't make changes 'visible' to
its downstream sites until it completes its own sync.

-- 
						Ken Smith
- From there to here, from here to      |       kensmith at cse.buffalo.edu
  there, funny things are everywhere.   |
                      - Theodore Geisel |


More information about the freebsd-current mailing list