Re: Specifying commit timestamps over RA
From: Branko Čibej <brane_at_wandisco.com>
Date: Fri, 29 Nov 2013 17:57:50 +0100
On 29.11.2013 17:46, Bert Huijben wrote:
Sorry. Here it is again.
This is a multi-part message in MIME format.
On 29.11.2013 15:29, Ivan Zhakov wrote:
We don't have any code anywhere that would guarantee that svn:date
Other than that, it is perfectly OK for the dates to be out of order. If
$ svn log -r0:HEAD ^/subversion --limit 1 | grep ^r
You're also missing the entire point of the discussion: the intent of
-- Branko Čibej | Director of Subversion WANdisco // Non-Stop Data e. brane_at_wandisco.com --------------030803050103010804020807 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit <html> <head> <meta content="text/html; charset=UTF-8" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> <div class="moz-cite-prefix">On 29.11.2013 15:29, Ivan Zhakov wrote:<br> </div> <blockquote cite="mid:CABw-3YcJ8Asvy8T+d1cd8DKnJ6iOMXEsbbYeHtcMtOhGh7a0rQ_at_mail.gmail.com" type="cite"> <pre wrap="">On 27 November 2013 22:57, Philip Martin <a class="moz-txt-link-rfc2396E" href="mailto:philip.martin_at_wandisco.com"><philip.martin_at_wandisco.com></a> wrote: </pre> <blockquote type="cite"> <pre wrap="">In 1.9 we have a new API svn_fs_commit_txn2 that allows 'svnadmin load' to create a revision with a specified timestamp rather than having to make a commit with the "wrong" date followed by a revision property change to set svn:date to the correct value. WANdisco are interested in making this feature available over RA so that it can be used for replication. svnsync could use such an implementation to avoid having to make an svn:date revision property change after each commit. </pre> </blockquote> <pre wrap="">While I added svn_fs_commit_txn2() function I think it should not be exposed through svn_repos_* and RA layer. FS layer currently doesn't treat svn:date as special property except commit. And for commit operation it just an option add timestamp within lock to guarantee them strictly ordered. As far I remember Michael C. Pilato said somewhere that this intentional FS layer design. Repos layer is different: it relies on svn:date order in functions like svn_repos_dated_revision(). Repos layer has functions to load repository dump, but this dump supposed to be created by svn_repos_dump_fs() and have valid svn:date order. Adding option to specify custom svn:date for new revision in svn_repos() layer will break this invariant.</pre> </blockquote> <br> We don't have any code anywhere that would guarantee that svn:date values are in-order, and we've known for 10 years that dated revision searches or ranges yield indeterminate results if the dates <i>within the searched subtree</i> are not in order.<br> <br> Other than that, it is perfectly OK for the dates to be out of order. If you don't believe me, you only have to look at the import of the Subversion repository into the ASF repo:<br> <pre>$ svn log -r0:HEAD ^/subversion --limit 1 | grep ^r r836401 | joes | 2009-11-15 20:53:16 +0100 (Sun, 15 Nov 2009) | 1 line $ svn log -r836402:HEAD ^/subversion --limit 1 | grep ^r r836420 | (no author) | 2000-03-01 03:32:07 +0100 (Wed, 01 Mar 2000) | 1 line </pre> <blockquote cite="mid:CABw-3YcJ8Asvy8T+d1cd8DKnJ6iOMXEsbbYeHtcMtOhGh7a0rQ_at_mail.gmail.com" type="cite"> </blockquote> <br> You're also missing the entire point of the discussion: the intent of the proposed change is to be able to sync repository mirrors in such a way that both the contents and the revprops, including the original svn:date value of the master repo, can be atomically committed to the mirror. In other words, the intent is to <i>reduce</i> the probability of having out-of-order dates on the mirror.<br> <br> -- Brane<br> <br> <div class="moz-signature">-- <br> <span style="font-face:sans-serif;font-size:9pt;line-height:18pt">Branko Čibej <span style="color: #f90">|</span> <span style="font-weight:bold">Director of Subversion</span> <br> WANdisco <span style="color: #f90">//</span> <span style="font-style:oblique">Non-Stop Data</span> <br> <span style="color: #ccc">e.</span> <a class="moz-txt-link-abbreviated" href="mailto:brane_at_wandisco.com">brane_at_wandisco.com</a></span></div> </body> </html> --------------030803050103010804020807--Received on 2013-11-29 17:58:34 CET
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