Re: [BUGS] BUG #14230: Wrong timeline returned by pg_stop_backup on a standby

On Fri, Jul 8, 2016 at 6:40 PM, Marco Nenciarini
<marco(dot)nenciarini(at)2ndquadrant(dot)it> wrote:
> The resulting backup is working perfectly, because Postgres has no use
> for pg_stop_backup LSN, but this can confuse any tool that uses the stop
> LSN to figure out which WAL files are needed by the backup (in this case
> the only file needed is the one containing the start checkpoint).
>
> After some discussion with Álvaro, my proposal is to avoid that by
> returning the stoppoint as the maximum between the startpoint and the
> min_recovery_end_location, in case of backup from the standby.

You are facing a pattern similar to the problem reported already on
this thread by Horiguchi-san:
http://www.postgresql.org/message-id/20160609.215558.118976703.horiguchi.kyotaro@lab.ntt.co.jp
And it seems to me that you are jumping to an incorrect conclusion,
what we'd want to do is to update a bit more aggressively the minimum
recovery point in cases on a node in recovery in the case where no
buffers are flushed by other backends.
--
Michael