On 2021/03/11 8:30, Thomas Munro wrote:
On Thu, Mar 11, 2021 at 11:38 AM Thomas Munro <thomas.mu...@gmail.com> wrote:
On Thu, Mar 11, 2021 at 11:01 AM Michael Brown
<michael.br...@discourse.org> wrote:
* is there a knob missing we can configure?
* can we get an opt-in knob to use a single sync() call instead of a
recursive fsync()?
* would you be open to merging a patch providing said knob?
* is there something else we missed?
As discussed on that other thread, I don't think sync() is an option
(it doesn't wait on all OSes or in the standard and it doesn't report
errors). syncfs() on Linux 5.8+ looks like a good candidate though,
and I think we'd consider a patch like that. I mean, I even posted
one[1] in that other thread. There will of course be cases where
that's slower (small database sharing filesystem with other software
that has a lot of dirty data to write back).
Thinking about this some more, if you were to propose a patch like
that syncfs() one but make it a configurable option, I'd personally be
in favour of trying to squeeze it into v14. Others might object on
commitfest procedural grounds, I dunno, but I think this is a real
operational issue and that's a fairly simple and localised change.
+1 to push this kind of change into v14!!
I've run into a couple of users who have just commented that recursive
fsync() code out!
BTW, we can skip that recursive fsync() by disabling fsync GUC even without
commenting out the code?
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
