Re: is there a warm standby sync trigger?

On Tue, Nov 25, 2014 at 6:37 PM, Sameer Kumar <sameer(dot)kumar(at)ashnik(dot)com> wrote:
>
> On Fri, Oct 24, 2014 at 8:01 PM, Michael Paquier <michael(dot)paquier(at)gmail(dot)com>
> wrote:
>>
>> On Fri, Oct 24, 2014 at 12:30 AM, John Smith <jayzee(dot)smith(at)gmail(dot)com>
>> wrote:
>> >
>> > i want to setup a warm standby that listens 24/7 but only syncs when
>> > told to (ie only when i am ok with the database updates, will i
>> > trigger the sync).
>> > can i?
>> >
>> > i don't want to manually backup and restore like i do now.
>>
>> That's what pause_at_recovery_target is aimed for:
>> http://www.postgresql.org/docs/devel/static/recovery-target-settings.html
>> Simply set up the recovery target you want to check, and use
>> pause_at_recovery_target to put the standby in a latent state you can
>> check. If the state of your server does not satisfy your needs,
>> shutdown the server and change the target. Note that operations are
>> not backward btw.
>
>
> If you were using hot-standby, you could have used pg_pause_recovery() /
> pg_resume_recovery()
>
> To pause when needed and continue later. e.g. when you are doing bulk loads
> or during a window when you see network congestion.
>
>
> Best Regards,
>
> Sameer Kumar | Database Consultant
>
> ASHNIK PTE. LTD.
>
> 101 Cecil Street, #11-11 Tong Eng Building, Singapore 069533
>
> M: +65 8110 0350 T: +65 6438 3504 | www.ashnik.com
>
>
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I have never heard of pg_pause_recovery() or pg_resume_recovery().
However, you can use pg_xlog_replay_pause() and
pg_xlog_replay_resume() to pause and resume recovery. As Sameer
mentioned, they require the system to be in hot standby mode to use
them.