Re: New trigger option of pg_standby

Hi,

On Mon, Apr 13, 2009 at 2:52 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> But, a lookahead nextWALfile seems to work fine.
>
> if (triggered)
> {
>    if (smartMode && nextWALfile exists)
>        exit(0)
>    else
>    {
>        delete trigger file
>        exit(1)
>    }
> }

Umm... in this algorithm, the trigger file remains after failover
if the nextWALfile has the invalid record which means the end
of WAL files.

I'd like to propose another simple idea; pg_standby deletes the
trigger file *whenever* the nextWALfile is a timeline history file.
A timeline history file is restored at the end of recovery, so it's
guaranteed that the trigger file is deleted whether nextWALfile
exists or not.

A timeline history file is restored also at the beginning of
recovery, so the accidentally remaining trigger file is deleted
in early warm-standby as a side-effect of this idea.

How does that sound?

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center