Re: [PATCH] Make pg_basebackup configure and start standby [Review]

2012-10-11 02:02 keltezéssel, Fujii Masao írta:
> On Thu, Oct 11, 2012 at 3:36 AM, Boszormenyi Zoltan <zb@cybertec.at> wrote:
>> 2012-10-10 18:23 keltezéssel, Fujii Masao írta:
>>> When tar output format is specified together with -R option, recovery.conf
>>> is
>>> not included in base.tar. I think it should.
>>
>> Why? This patch only promises to write the recovery.conf into the
>> directory specified with -D.
> Because it's more user-friendly. If recovery.conf is not included in base.tar,
> when base.tar is extracted to disk to use the backup, a user always needs
> to copy recovery.conf to the extracted directory. OTOH if it's included in
> base.tar, such copy operation is not required and we can simplify the
> procedures to use the backup a bit.

It's implemented now.

>>> +        setting up the standby. Since creating a backup for a standalone
>>> +        server with <option>-x</option> or <option>-X</option> and adding
>>> +        a recovery.conf to it wouldn't make a working standby, these
>>> options
>>> +        naturally conflict.
>>>
>>> Is this right? ISTM that basically we can use pg_basebackup -x to take
>>> a base backup for starting the standby for now. No?
>>
>> I don't know. Pointers?
> There is no restriction that the backup which was taken by using
> pg_basebackup -x cannot be used to start the standby. So I wonder
> why -R option cannot work together with -x. It's useful if recovery.conf
> is automatically written even with pg_basebackup -x.

There was a problem with 9.0.x (maybe even with 9.1) that the backup
failed to come up as a standby if -x or -X was specified. I don't know
if it was a bug, limitation or intended behaviour.

Before removing the check for conflicting options, I would like to ask:
is there such a known conflict with --xlog-method=stream?

> And I found another problem: when -(stdout) is specified in -D option,
> recovery.conf fails to be written.
>
> $ pg_basebackup -D- -F t -c fast -R > hoge.tar
> NOTICE:  WAL archiving is not enabled; you must ensure that all
> required WAL segments are copied through other means to complete the
> backup
> pg_basebackup: cannot create -/recovery.conf: No such file or directory

Now it works with recovery.conf written into the tar itself. I also tried

$ pg_basebackup -D- -Ft -R

and the directory named "-" was created and of course the recovery.conf
inside it. Is this the intended behaviour regarding "stdout is to be treated
as a directory"?

Best regards,
Zoltán Böszörményi

--
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Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt, Austria
Web: http://www.postgresql-support.de     http://www.postgresql.at/