Re: Support for N synchronous standby servers - take 2

On Thu, Apr 7, 2016 at 11:56 AM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>
> On Thu, Apr 7, 2016 at 2:48 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
wrote:
> > On Thu, Apr 7, 2016 at 10:02 AM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
wrote:
> >>
> >> On Thu, Apr 7, 2016 at 1:22 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
> >> wrote:
> >> >
> >> > But for that, I think we don't need to do anything extra. I mean
> >> > write_nondefault_variables() will automatically write the non-default
> >> > value
> >> > of variable and then during backend initialization, it will call
> >> > read_nondefault_variables which will call set_config_option for
> >> > non-default
> >> > parameters and that should set the required value if we have assign_*
> >> > function defined for the variable.
> >>
> >> Yes if the variable that we'd like to pass to a backend is BOOL, INT,
> >> REAL, STRING or ENUM. But SyncRepConfig variable is a bit more
> >> complicated.
> >>
> >
> > SyncRepConfig is a parsed result of SyncRepStandbyNames, why you want to
> > pass that? I assume that current non-default value of
SyncRepStandbyNames
> > will be passed via write_nondefault_variables(), so we can use that to
> > regenerate SyncRepConfig.
>
> Yes, so SyncRepUpdateConfig() needs to be called by a backend after fork,
> to regenerate SyncRepConfig from the passed value of SyncRepStandbyNames.
> This is the approach of (2) which I explained upthread. assign_XXX
function
> doesn't seem to be helpful for this case.
>

Then where do you want to call it? Also, this is only required for
EXEC_BACKEND builds.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com