Re: wake up logical workers after ALTER SUBSCRIPTION

On Thu, Dec 15, 2022 at 4:47 AM Nathan Bossart <nathandbossart@gmail.com> wrote:
>
> On Wed, Dec 14, 2022 at 02:02:58PM -0500, Tom Lane wrote:
> > Maybe we could have workers that are exiting for that reason set a
> > flag saying "please restart me without delay"?
>
> That helps a bit, but there are still delays when starting workers for new
> subscriptions.  I think we'd need to create a new array in shared memory
> for subscription OIDs that need their workers started immediately.
>

That would be tricky because the list of subscription OIDs can be
longer than the workers. Can't we set a boolean variable
(check_immediate or something like that) in LogicalRepCtxStruct and
use that to traverse the subscriptions? So, when any worker will
restart because of a parameter change, we can set the variable and
send a signal to the launcher. The launcher can then check this
variable to decide whether to start the missing workers for enabled
subscriptions.

-- 
With Regards,
Amit Kapila.