* Re: cvs update vs. git pull
2010-05-28 9:21 cvs update vs. git pull René Moser
@ 2010-05-28 9:35 ` Andreas Ericsson
2010-05-28 9:46 ` Tor Arntsen
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Andreas Ericsson @ 2010-05-28 9:35 UTC (permalink / raw)
To: René Moser; +Cc: git
On 05/28/2010 11:21 AM, René Moser wrote:
> Hi
>
> I use git since a while for my own projects (how surprise).
>
> The company I work for still uses a CVS(nt), and this sucks, time to
> changed that. We have a use case we often have problems with. If git would
> solve this problem, I would really have a good arg for the managers.
>
> The codebase managed by CVS is quite huge and therefore we have daily and
> nightly builds.
>
> One problem we have is, that if there is a commit to cvs while the cvs
> update of the build job is running (and this takes 20 minutes), then we
> get some inconsistence, the build will fail.
>
> So the question is, if we would use git, this inconsistence would not be
> possible because the git pull will get the state of the sha1. Right?
>
Right.
--
Andreas Ericsson andreas.ericsson@op5.se
OP5 AB www.op5.se
Tel: +46 8-230225 Fax: +46 8-230231
Considering the successes of the wars on alcohol, poverty, drugs and
terror, I think we should give some serious thought to declaring war
on peace.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: cvs update vs. git pull
2010-05-28 9:21 cvs update vs. git pull René Moser
2010-05-28 9:35 ` Andreas Ericsson
@ 2010-05-28 9:46 ` Tor Arntsen
2010-05-28 9:54 ` Matthieu Moy
2010-05-28 15:58 ` Robin Rosenberg
3 siblings, 0 replies; 6+ messages in thread
From: Tor Arntsen @ 2010-05-28 9:46 UTC (permalink / raw)
To: René Moser; +Cc: git
On Fri, May 28, 2010 at 11:21, René Moser <mail@renemoser.net> wrote:
> Hi
>
> I use git since a while for my own projects (how surprise).
>
> The company I work for still uses a CVS(nt), and this sucks, time to
> changed that. We have a use case we often have problems with. If git would
> solve this problem, I would really have a good arg for the managers.
>
> The codebase managed by CVS is quite huge and therefore we have daily and
> nightly builds.
So do we, where I work.
> One problem we have is, that if there is a commit to cvs while the cvs
> update of the build job is running (and this takes 20 minutes), then we
> get some inconsistence, the build will fail.
Yes. That's how it works with CVS. We try to work around that problem
by using automatic tags ('nightly'-something) set individually on each
module, common for the whole repo, and then we 'cvs export' by tag
instead of cvs update. This works reasonably well (and is reproducible
due to the tag), but is not anywhere as fast as git would be.
> So the question is, if we would use git, this inconsistence would not be
> possible because the git pull will get the state of the sha1. Right?
Git commits are atomic, so you won't see that inconsistency problem
with git. So, Right.
-Tor
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: cvs update vs. git pull
2010-05-28 9:21 cvs update vs. git pull René Moser
2010-05-28 9:35 ` Andreas Ericsson
2010-05-28 9:46 ` Tor Arntsen
@ 2010-05-28 9:54 ` Matthieu Moy
2010-05-28 13:07 ` Ævar Arnfjörð Bjarmason
2010-05-28 15:58 ` Robin Rosenberg
3 siblings, 1 reply; 6+ messages in thread
From: Matthieu Moy @ 2010-05-28 9:54 UTC (permalink / raw)
To: René Moser; +Cc: git
René Moser <mail@renemoser.net> writes:
> One problem we have is, that if there is a commit to cvs while the cvs
> update of the build job is running (and this takes 20 minutes), then we
> get some inconsistence, the build will fail.
Git will also bring a big performance improvement here. The duration
of the "git pull" will be mostly O(number of modifications since last
pull), not O(total number of files).
> So the question is, if we would use git, this inconsistence would not be
> possible because the git pull will get the state of the sha1. Right?
Actually, if you use almost anything but CVS (i.e. even SVN can do
that), you will get "atomic commits", i.e. a commit touching multiple
files is either seen as completed or not seen at all.
--
Matthieu Moy
http://www-verimag.imag.fr/~moy/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: cvs update vs. git pull
2010-05-28 9:54 ` Matthieu Moy
@ 2010-05-28 13:07 ` Ævar Arnfjörð Bjarmason
0 siblings, 0 replies; 6+ messages in thread
From: Ævar Arnfjörð Bjarmason @ 2010-05-28 13:07 UTC (permalink / raw)
To: Matthieu Moy; +Cc: René Moser, git
On Fri, May 28, 2010 at 09:54, Matthieu Moy
<Matthieu.Moy@grenoble-inp.fr> wrote:
> René Moser <mail@renemoser.net> writes:
>
>> One problem we have is, that if there is a commit to cvs while the cvs
>> update of the build job is running (and this takes 20 minutes), then we
>> get some inconsistence, the build will fail.
>
> Git will also bring a big performance improvement here. The duration
> of the "git pull" will be mostly O(number of modifications since last
> pull), not O(total number of files).
A while back I tried converting a huge (~40k directories) CVS
repository to SVN and Git. Both CVS and SVN took around 10 minutes to
cvs/svn up. git clone took around 8 minutes but each pull was around
5-15 seconds (I/O and network bound).
They eventually picked Bazaar for non-technical reasons. But yeah,
Git's much faster to upgrade than CVS/SVN.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: cvs update vs. git pull
2010-05-28 9:21 cvs update vs. git pull René Moser
` (2 preceding siblings ...)
2010-05-28 9:54 ` Matthieu Moy
@ 2010-05-28 15:58 ` Robin Rosenberg
3 siblings, 0 replies; 6+ messages in thread
From: Robin Rosenberg @ 2010-05-28 15:58 UTC (permalink / raw)
To: René Moser; +Cc: git
fredagen den 28 maj 2010 11.21.12 skrev René Moser:
> Hi
>
> I use git since a while for my own projects (how surprise).
>
> The company I work for still uses a CVS(nt), and this sucks, time to
> changed that. We have a use case we often have problems with. If git would
> solve this problem, I would really have a good arg for the managers.
>
> The codebase managed by CVS is quite huge and therefore we have daily and
> nightly builds.
>
> One problem we have is, that if there is a commit to cvs while the cvs
> update of the build job is running (and this takes 20 minutes), then we
> get some inconsistence, the build will fail.
Perform export/checkout using a timestamp to avoid this. You should also
require that no checkins to your branch have happend during a period, say 10
minutes, before starting the build.
> So the question is, if we would use git, this inconsistence would not be
> possible because the git pull will get the state of the sha1. Right?
Yes. It's hard to predict what happens when you have multiple repos involved,
in the build. Requiring no changes (on the build branch) in all repos is one
option.
-- robin
^ permalink raw reply [flat|nested] 6+ messages in thread