Re: [BUG] pg_basebackup from disconnected standby fails

On Thu, Oct 27, 2016 at 2:59 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Wed, Oct 26, 2016 at 2:06 AM, Michael Paquier
> <michael.paquier@gmail.com> wrote:
>> But yes, thinking *harder*, I agree that updating minRecoveryPoint
>> just after the checkpoint record would be fine and removes the need to
>> have more WAL than necessary in for a backup taken from a standby.
>> That will also prevent cases where minRecoveryPoint is older than the
>> recovery start point. On top of that the cost of an extra call to
>> UpdateControlFile() looks cheap considering that CreateRestartPoint()
>> is called only by the checkpointer or at shutdown.
>>
>> Just coding things this solution gives roughtly the attached? The TAP
>> test passes btw.
>
> I think that still leaves a race condition, right?  It's got to be
> part of the SAME control file update that advances the redo pointer.

Right, thanks for double-checking... There is no meaning to do that
out of the ControlFileLock taken previously...
--
Michael