Re: speed up a logical replica setup

On Wed, Nov 1, 2023 at 7:10 PM Ashutosh Bapat
 wrote:
>
> I noticed some differences between this and a similar utility
> https://github.com/2ndQuadrant/pglogical/blob/REL2_x_STABLE/pglogical_create_subscriber.c.
> I will be reviewing these differences next to see if we are missing
> anything here.

Some more missing things to discuss

Handling signals - The utility cleans up left over objects on exit.
But default signal handlers will make the utility exit without a
proper cleanup [1]. The signal handlers may clean up the objects
themselves or at least report the objects that need tobe cleaned up.

Idempotent behaviour - Given that the utility will be used when very
large amount of data is involved, redoing everything after a network
glitch or a temporary failure should be avoided. This is true when the
users start with base backup. Again, I don't think we should try to be
idempotent in v1 but current design shouldn't stop us from doing so. I
didn't find anything like that in my review. But something to keep in
mind.

That finishes my first round of review. I will wait for your updated
patches before the next round.

[1] NOTEs section in man atexit().


--
Best Wishes,
Ashutosh Bapat