Re: wake up logical workers after ALTER SUBSCRIPTION

On Tue, Jan 03, 2023 at 11:43:59AM +0530, Amit Kapila wrote:
> On Wed, Dec 7, 2022 at 11:42 PM Nathan Bossart <nathandbossart(at)gmail(dot)com> wrote:
>> After sleeping on this, I think we can do better. IIUC we can simply check
>> for AllTablesyncsReady() at the end of process_syncing_tables_for_apply()
>> and wake up the logical replication workers (which should just consiѕt of
>> setting the current process's latch) if we are ready for two_phase mode.
>
> How just waking up will help with two_phase mode? For that, we need to
> restart the apply worker as we are doing at the beginning of
> process_syncing_tables_for_apply().

Right. IIRC waking up causes the apply worker to immediately call
process_syncing_tables_for_apply() again, which will then proc_exit(0) as
appropriate. It might be possible to move the restart logic to the end of
process_syncing_tables_for_apply() to avoid this extra wakeup. WDYT?

--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com