On 7 November 2014 02:44, Stefan Fuhrmann <stefan.fuhrmann_at_wandisco.com> wrote:
> [This goes mostly to Ivan but the last part goes to Brane. Don't want to
> sub-thread here.]
> On Thu, Nov 6, 2014 at 8:24 PM, Branko Čibej <brane_at_wandisco.com> wrote:
>> On 06.11.2014 20:03, ivan_at_apache.org wrote:
>> > Author: ivan
>> > Date: Thu Nov 6 19:03:31 2014
>> > New Revision: 1637184
>> > URL: http://svn.apache.org/r1637184
>> > Log:
>> > Make FSFSv7 repositories always use consistent addressing mode, instead
>> > of
>> > saving revision number from which logical addressing was enabled.
>> Congrats on finally doing something concrete about FSFSv7.
> +1 on the meta point.
> It looks a bit like a rushed commit, though (partly corrected by the
> r1637186 commit). Documentation update is missing:
> structure:Filesystem format options
> * update addressing mode description
> * update docstring
> * update docstring
Thanks for review! I've fixed these typos in r1637330.
> I'm -.5 on removing the "mixed addressing" feature for exactly the
> points made by Brane.
I'm going to reply on your comments a bit later.
> Brane, you might confuse this with 'svnadmin pack'. The thing
> about upgrade is that we have a nasty FS API limitation that
> is a missing concept of read sessions / locks.
But I want to comment this one particular and important thing right
now. Please do not treat all things that are unclear for you as
a "nasty limitations".
Missing of read sessions/locks is a core (and pretty successful)
design decision of the FSFS. Quoting original Greg Hudson email
in 2004 :
* Despite the above, scalability may be better, because there are no
read-locks and no potential interference between readers and other
readers, or between readers and writers.
This solution is perfectly works for ten (!) years. If you want to change
(or beat) this approach, please do this in the experimental FSX
format. All other 'revolutionary' FSFS-related performance improvements
should be also implemented there.
Received on 2014-11-07 16:18:29 CET