On Wed, Apr 2, 2014 at 12:13 PM, Ivan Zhakov <i...@visualsvn.com> wrote:
> On 31 January 2014 14:57, Ivan Zhakov <i...@visualsvn.com> wrote: > > On 31 January 2014 05:50, Evgeny Kotkov <evgeny.kot...@visualsvn.com> > wrote: > >>> This only affects non-sharded repositories with rev-local IDs, > >>> i.e. those in SVN 1.4 format. For those, it is writing 3 files > >>> instead of 2 per rev now. > >> > >> I assume you are talking about r1560723 [1]. If I read the code > correctly... > >> [[[ > >> if ( (!max_files_per_dir || rev % max_files_per_dir == 0) > >> && dst_ffd->format >= SVN_FS_FS__MIN_NO_GLOBAL_IDS_FORMAT) > >> SVN_ERR(hotcopy_update_current(&dst_youngest, dst_fs, rev, > iterpool)); > >> ]]] > >> > >> ...hotcopy now checkpoints after every revision for all non-sharded > repositories > >> with FSFS format >= 3. So, checkpointing happens for all FSFS format > 1/2 > >> repositories upgraded via 'svnadmin upgrade' (with linear layout), that > were > >> not fsfs-reshard'ed or dump/loaded into a repository with newer format. > >> > >> I am not aware of how many people reshard or dump/load their old > repositories > >> after upgrade, but I did a quick benchmark for a real-world repository > and on my > >> machine it shows 7x performance degradation with checkpointing enabled. > Is it > >> worth the ability to re-run the backup from a checkpoint upon > cancellation? > >> > >> [[[ > >> # svnrdump http://googletest.googlecode.com/svn/trunk/ > >> # load the dump into a --compatible-version=1.3 repository > >> # upgrade the repository with the most recent svnadmin > >> > >> # disable checkpointing, benchmark making 100 hotcopy backups: > >> real 0m18.741s > >> user 0m2.552s > >> sys 0m13.432s > >> > >> # now enable checkpointing and repeat the benchmark: > >> real 2m5.793s > >> user 0m0.836s > >> sys 0m34.840s > >> ]]] > >> > >> [1] http://svn.apache.org/viewvc?view=revision&revision=r1560723 > >> > > That's what I suspected. In this case I think r1560723 should not be > > backported to 1.8.x for the following reasons: > > 1. Significant performance degradation for 'svnadmin hotcopy' with > > '--incremental' flag. > > 2. The change doesn't fix original circular dependency problem in FSFS > > 3. 'svnadmin recover' writes fake value to CURRENT file which very bad > > practice IMHO and could lead undefined consequences. > > > Hi Stefan, > > Is this problem fixed or it's better to revert r1560723 for reasons I > stated above? > Hi Ivan, Evgeny applied his patch a month ago as r1573744. -- Stefan^2.
