On 7 November 2014 02:44, Stefan Fuhrmann <stefan.fuhrm...@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 <br...@wandisco.com> wrote: >> >> On 06.11.2014 20:03, i...@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 > > fs_fs.c:read_format() > * update docstring > > transaction.c:store_l2p_index_entry() > * 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 [1]: [[[ * 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. [1] http://svn.haxx.se/dev/archive-2004-05/1104.shtml -- Ivan Zhakov
