All, * Masahiko Sawada (sawada.m...@gmail.com) wrote: > On Tue, Jul 25, 2017 at 4:43 AM, Michael Paquier > <michael.paqu...@gmail.com> wrote: > > On Mon, Jul 24, 2017 at 6:45 PM, Stephen Frost <sfr...@snowman.net> wrote: > >> What the change would do is make the pg_stop_backup() caller block until > >> the last WAL is archvied, and perhaps that ends up taking hours, and > >> then the connection is dropped for whatever reason and the backup fails > >> where it otherwise.... what? wouldn't have been valid anyway at that > >> point, since it's not valid until the last WAL is actually archived. > >> Perhaps eventually it would be archived and the caller was planning for > >> that and everything is fine, but, well, that feels like an awful lot of > >> wishful thinking. > > > > Letting users taking unconsciously inconsistent backups is worse than > > potentially breaking scripts that were actually not working as > > Postgres would expect. So I am +1 for back-patching a lighter version > > of the proposed patch that makes the wait happen on purpose. > > > >>> > I'd hate to have to do it, but we could technically add a GUC to address > >>> > this in the back-branches, no? I'm not sure that's really worthwhile > >>> > though.. > >>> > >>> That would be mighty ugly. > >> > >> Oh, absolutely agreed. > > > > Yes, let's avoid that. We are talking about a switch aimed at making > > backups potentially inconsistent. > > Thank you for the review comments! > Attached updated the patch. The noting in pg_baseback doc will be > necessary for back branches if we decided to not back-patch it to back > branches. So it's not contained in this patch for now. > > Regarding back-patching this to back branches, I also vote for > back-patching to back branches. Or we can fix the docs of back > branches and fix the code only in PG10. I expect that the user who > wrote a backup script has done enough functional test and dealt with > this issue somehow, but since the current doc clearly says that > pg_stop_backup() waits for all WAL to be archived we have to make a > consideration about there are users who wrote a wrong backup script. > So I think we should at least notify it in the minor release.
That sounds like we have at least three folks thinking that this should be back-patched, and one who doesn't. Does anyone else wish to voice an opinion regarding back-patching this..? Thanks! Stephen
Description: Digital signature