Re: BUG #15346: Replica fails to start after the crash

Greetings,

* Michael Paquier (michael@paquier.xyz) wrote:
> On Sat, Aug 25, 2018 at 09:54:39AM +0200, Alexander Kukushkin wrote:
> > Why the number of tuples in the xlog is greater than the number of
> > tuples on the index page?
> > Because this page was already overwritten and its LSN is HIGHER than
> > the current LSN!
>
> That's annoying.  Because that means that the control file of your
> server maps to a consistent point which is older than some of the
> relation pages.  How was the base backup of this node created?  Please
> remember that when taking a base backup from a standby, you should
> backup the control file last, as there is no control of end backup with
> records available.  So it seems to me that the origin of your problem
> comes from an incorrect base backup expectation?

Yeah, we really need to know how this system was built.  If it was built
using the low-level pg_start/stop_backup, then which API was used- the
old one that creates a backup_label file, or the new API which requires
the user to create the backup_label file?  I haven't followed this
thread very closely, but I wonder if maybe the new API was used, but no
backup_label file was created, making PG think it was doing crash
recovery instead of restoring from a file-level backup...

Thanks!

Stephen