Re: [9.3 bug] disk space in pg_xlog increases during archive recovery

On Fri, Aug 2, 2013 at 10:52 AM, Michael Paquier
<michael(dot)paquier(at)gmail(dot)com> wrote:
>
>
>
> On Fri, Aug 2, 2013 at 12:24 AM, MauMau <maumau307(at)gmail(dot)com> wrote:
>>
>> From: "Fujii Masao" <masao(dot)fujii(at)gmail(dot)com>
>>
>>>> However, isn't StandbyRequested true (= standby_mode set to on) to
>>>> enable
>>>> warm standby?
>>>
>>>
>>> We can set up warm-standby by using pg_standby even if standby_mode =
>>> off.
>>
>>
>> I see. However, I understand that pg_standby is a legacy feature, and the
>> current way to setup a warm standby is to set standby=on and restore_command
>> in recovery.conf. So I think it might not be necessary to support cascading
>> replication with pg_standby, if supporting it would prevent better
>> implementation of new features.
>
> You are right about that, you should stick with the core features as much as
> you can and limit the use of wrapper utilities. Since 9.1 and the apparition
> of a built-in standby mode inside Postgres (with the apparition of the GUC
> parameter hot_standby), it seems better to use that instead of pg_standby,
> which would likely (personal opinion, feel free to scream at me) be removed
> in a future release.

I'm sure that there are some users who use pg_standby for warm-standby
for some reasons, for example, the document (*1) explains such a configuration,
a user can specify the file-check-interval (by using -s option), and so on.
I agree that using pg_standby + cascade replication would be very rare.
But I'm not confident that *no one* uses pg_standby + cascade replication.

(*1) http://www.postgresql.org/docs/devel/static/log-shipping-alternative.html

Regards,

--
Fujii Masao