On Mon, Jul 7, 2025 at 11:22 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > > Dilip Kumar <dilipbal...@gmail.com> writes: > >> IMHO we can just query the 'max_slot_wal_keep_size' after > >> start_postmaster() and check what is the final resultant value. So now > >> we will only throw an error if the final value is not -1. And we can > >> remove the hook from the server all together. Thoughts? > > > I could come up with an attachment patch. > > I don't love this patch. It's adding more cycles and more complexity > to pg_upgrade, when there is a simpler and more direct solution: > re-order the construction of the postmaster command line in > start_postmaster() so that our "-c max_slot_wal_keep_size" will > override anything the user supplies.
Yeah that's right, one of the purposes of this change was to keep all logic at the pg_upgrade itself and remove the server hook altogether. But I think it was not a completely successful attempt to do that because still there was some awareness of this InvalidatePossiblyObsoleteSlot(). And I agree it would add an extra call in pg_upgrade. > There's a bigger picture here, though. The fundamental thing that > I find wrong with the current code is that knowledge of and > responsibility for this max_slot_wal_keep_size hack is spread across > both pg_upgrade and the server. It would be better if it were on > just one side. Now, unless we want to change that Assert that > 8bfb231b4 put into InvalidatePossiblyObsoleteSlot(), the server side > is going to be aware of this decision. So I'm inclined to think > that we should silently enforce max_slot_wal_keep_size = -1 in > binary-upgrade mode in the server's GUC check hook, and then remove > knowledge of it from pg_upgrade altogether. Maybe the same for > idle_replication_slot_timeout, which really has got the same issue > that we don't want users overriding that choice. Yeah this change makes sense, currently we are anyway trying to force this to be -1 from pg_upgrade and server is also trying to validate if anything else is set during binary upgrade, so better to keep logic at one place. I will work on this patch, thanks. -- Regards, Dilip Kumar Google
