Re: pg_upgrade and rsync

On 1/22/15 10:05 PM, Stephen Frost wrote:<br /><blockquote cite="mid:20150123030509.GJ3854@tamriel.snowman.net"
type="cite"><blockquotetype="cite"><pre wrap="">In addition, there is a possible race condition in rsync where a file 
that is modified in the same second after rsync starts to copy will not
be picked up in a subsequent rsync unless --checksum is used.  This is
fairly easy to prove and is shown here:

<a class="moz-txt-link-freetext"
href="https://github.com/pgmasters/backrest/blob/dev/test/lib/BackRestTest/BackupTest.pm#L1667">https://github.com/pgmasters/backrest/blob/dev/test/lib/BackRestTest/BackupTest.pm#L1667</a>
</pre></blockquote><pre wrap="">
Right, though that isn't really an issue in this specific case- we're
talking about post-pg_upgrade but before the upgraded cluster has
actually been started, so nothing should be modifying these files.
</pre></blockquote><br /> Indeed.  This was really directed more at what Bruce said:<br /><blockquote><pre wrap="">I am
thinkingthe fix for standys would be similar to what we recommand 
for upgrades with link mode using a rsync-created copy, e.g. use rsync
while the master is running to create a copy of the standby, then shut
down the master and run rsync again.  However, at that point, you might
as well just take a base backup and be done with it.
</pre></blockquote><pre class="moz-signature" cols="72">--
- David Steele
<a class="moz-txt-link-abbreviated" href="mailto:david@pgmasters.net">david@pgmasters.net</a></pre>