На пт, 12.09.2025 г. в 3:37 Michael Paquier <[email protected]> написа:
> Okay, the bit about the cascading standby is a useful piece of > information. Do you have some data about the relation reported in the > error message this is choking on based on its OID? Is this actively > used in read-only workloads, with the relation looked at in the > cascading standby? This objoid=767325170 is non-existent, nor was it present in the previous shutdown (objoid=4169049057). So I guess it is something quasi-temporary that has been dropped afterwards. > Is hot_standby_feedback enabled in the cascading > standby? Yes, hot_standby_feedback = on. > With which process has this cascading standby been created? > Does the workload of the primary involve a high consumption of OIDs > for relations, say many temporary tables? > Yes, we have around 150 entries added and deleted per second in pg_class, and around 800 in pg_attribute. So something is actively creating and dropping tables all the time. > > Another thing that may help is the WAL record history. Are you for > example seeing attempts to drop twice the same pgstats entry in WAL > records? Perhaps the origin of the problem is in this area. A > refcount of 2 is relevant, of course. > How could we dig into this, i.e. inspecting such attempts in the WAL records? > > I have looked a bit around but nothing has popped up here, so as far > as I know you seem to be the only one impacted by that. > > 1d6a03ea4146 and dc5f9054186a are in 17.3, so perhaps something is > still off with the drop when applied to cascading standbys. A vital > piece of information may also be with "generation", which would show > up in the error report thanks to bdda6ba30cbe, and that's included in > 17.6. A first thing would be to update to 17.6 and see how things > go for these cascading setups. If it takes a couple of weeks to have > one report, we have a hunt that may take a few months at least, except > if somebody is able to find out the race condition here, me or someone > else. > > Is it enough to upgrade the replicas or we need to upgrade the primary as well? -- Kouber
