Re: [HACKERS] Broken hint bits (freeze)

On Tue, Jun 20, 2017 at 3:40 PM, Sergey Burladyan <eshkinkot@gmail.com> wrote:
> Bruce Momjian <bruce@momjian.us> writes:
>
>> On Mon, Jun 19, 2017 at 10:59:19PM -0400, Bruce Momjian wrote:
>> > On Tue, Jun 20, 2017 at 03:50:29AM +0300, Sergey Burladyan wrote:
>> > > 20 июн. 2017 г. 1:21 пользователь "Bruce Momjian" <bruce@momjian.us> написал:
>> > >
>> > >
>> > >     We are saying that Log-Shipping should match "Latest checkpoint
>> > >     location", but the WAL for that will not be sent to the standby, so it
>> > >     will not match, but that is OK since the only thing in the non-shipped
>> > >     WAL file is the checkpoint record.  How should we modify the wording on
>> > >     this?
>> > >
>> > >
>> > > I am afraid that without this checkpoint record standby cannot make
>> > > restartpoint
>> > > and without restartpoint it does not sync shared buffers into disk at
>> > > shutdown.
>> >

It seems to me at shutdown time on standby servers we specifically
make restart points.  See below code in ShutdownXLOG()

..
if (RecoveryInProgress())
CreateRestartPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_IMMEDIATE);
..

Do you have something else in mind?

>> > Uh, as I understand it the rsync is going to copy the missing WAL file
>> > from the new master to the standby, right, and I think pg_controldata
>> > too, so it should be fine.  Have you tested to see if it fails?
>
> It need old WAL files from old version for correct restore heap
> files. New WAL files from new version does not have this information.
>

So in such a case can we run rsync once before pg_upgrade?

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com