Re: Introduce XID age and inactive timeout based replication slot invalidation
От | Bharath Rupireddy |
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Тема | Re: Introduce XID age and inactive timeout based replication slot invalidation |
Дата | |
Msg-id | CALj2ACU-sJdiLfAcWd+8hnt4HSojH0UWFGnaGr9gxb2bYzYYSA@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: Introduce XID age and inactive timeout based replication slot invalidation (Amit Kapila <amit.kapila16@gmail.com>) |
Ответы |
Re: Introduce XID age and inactive timeout based replication slot invalidation
(Amit Kapila <amit.kapila16@gmail.com>)
|
Список | pgsql-hackers |
On Mon, Mar 11, 2024 at 11:26 AM Amit Kapila <amit.kapila16@gmail.com> wrote: > > > Hm. I get the concern. Are you okay with having inavlidation_reason > > separately for both logical and physical slots? In such a case, > > logical slots that got invalidated on the standby will have duplicate > > info in conflict_reason and invalidation_reason, is this fine? > > > > If we have duplicate information in two columns that could be > confusing for users. BTW, isn't the recovery conflict occur only > because of rows_removed and wal_level_insufficient reasons? The > wal_removed or the new reasons you are proposing can't happen because > of recovery conflict. Am, I missing something here? My understanding aligns with yours that the rows_removed and wal_level_insufficient invalidations can occur only upon recovery conflict. FWIW, a test named 'synchronized slot has been invalidated' in 040_standby_failover_slots_sync.pl inappropriately uses conflict_reason = 'wal_removed' logical slot on standby. As per the above understanding, it's inappropriate to use conflict_reason here because wal_removed invalidation doesn't conflict with recovery. > > Another idea is to make 'conflict_reason text' as a 'conflicting > > boolean' again (revert 007693f2a3), and have 'invalidation_reason > > text' for both logical and physical slots. So, whenever 'conflicting' > > is true, one can look at invalidation_reason for the reason for > > conflict. How does this sound? > > > > So, does this mean that conflicting will only be true for some of the > reasons (say wal_level_insufficient, rows_removed, wal_removed) and > logical slots but not for others? I think that will also not eliminate > the duplicate information as user could have deduced that from single > column. So, how about we turn conflict_reason to only report the reasons that actually cause conflict with recovery for logical slots, something like below, and then have invalidation_cause as a generic column for all sorts of invalidation reasons for both logical and physical slots? ReplicationSlotInvalidationCause cause = slot_contents.data.invalidated; if (slot_contents.data.database == InvalidOid || cause == RS_INVAL_NONE || cause != RS_INVAL_HORIZON || cause != RS_INVAL_WAL_LEVEL) { nulls[i++] = true; } else { Assert(cause == RS_INVAL_HORIZON || cause == RS_INVAL_WAL_LEVEL); values[i++] = CStringGetTextDatum(SlotInvalidationCauses[cause]); } -- Bharath Rupireddy PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com
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