Fujii-san,
I like the new patch using the content of the file to determine the
mode. Much easier to use at failover time.
On Fri, 2009-04-10 at 12:47 +0900, Fujii Masao wrote:
> > One problem with this patch is that in smart mode, the trigger file is not
> > deleted. That's different from current pg_standby behavior, and makes
> > accidental failovers after one failover more likely.
>
> Yes, it's because pg_standby cannot be sure when the trigger file
> can be removed in smart mode. If the trigger file is deleted as soon
> as it's found, just like in fast mode, pg_standby may keep waiting
> for WAL file again.
My understanding of smart mode is fairly simple:
if (triggered) {if (smartMode && nextWALfile+1 exists) exit(0);else{ delete trigger file exit(1);} }
If you perform a file lookahead (the +1) as shown above then you avoid
the problem Heikki observes.
-- Simon Riggs www.2ndQuadrant.comPostgreSQL Training, Services and Support