Re: avoid multiple hard links to same WAL file after a crash

On Tue, Jul 05, 2022 at 10:19:49AM +0900, Michael Paquier wrote:
> On Thu, May 05, 2022 at 08:10:02PM +0900, Michael Paquier wrote:
>> I'd agree with removing all the callers at the end.  pgrename() is
>> quite robust on Windows, but I'd keep the two checks in
>> writeTimeLineHistory(), as the logic around findNewestTimeLine() would
>> consider a past TLI history file as in-use even if we have a crash
>> just after the file got created in the same path by the same standby,
>> and the WAL segment init part.  Your patch does that.
> 
> As v16 is now open for business, I have revisited this change and
> applied 0001 to change all the callers (aka removal of the assertion
> for the WAL receiver when it overwrites a TLI history file).  The
> commit log includes details about the reasoning of all the areas
> changed, for clarity, as of the WAL recycling part, the TLI history
> file part and basic_archive. 

Thanks!  I wonder if we should add a comment in writeTimeLineHistoryFile()
about possible concurrent use by a WAL receiver and the startup process and
why that is okay.

-- 
Nathan Bossart
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