Re: wake up logical workers after ALTER SUBSCRIPTION

Nathan Bossart <nathandbossart(at)gmail(dot)com> writes:
> On Tue, Jan 10, 2023 at 10:59:14AM +0530, Amit Kapila wrote:
>> I haven't looked in detail but isn't it better to explain somewhere in
>> the comments that it achieves to rate limit the restart of workers in
>> case of error and allows them to restart immediately in case of
>> subscription parameter change?

> I expanded one of the existing comments to make this clear.

I pushed v17 with some mostly-cosmetic changes, including more comments.

> Of course, if the launcher restarts, then the notify_pid will no longer be
> accurate. However, I see that workers also register a before_shmem_exit
> callback that will send SIGUSR1 to the launcher_pid currently stored in
> shared memory. (I wonder if there is a memory ordering bug here.)

I think it's all close enough in reality. There are other issues in
this code, and I'm about to start a new thread about one I identified
while testing this patch, but I think we're in good shape on this
particular point. I've marked the CF entry as committed.

regards, tom lane