Re: Introduce XID age and inactive timeout based replication slot invalidation

On Mon, Jan 27, 2025 at 11:00 AM Nisha Moond <nisha.moond412@gmail.com> wrote:
>
> I discussed the above comments further with Peter off-list, and here
> are the v63 patches with the following changes:
>  patch-001: The Assert and related comments have been updated for clarity.
>

The 0001 patch should be discussed in a separate thread as those are
general improvements that are useful even without the main patch we
are trying to achieve in this thread. I suggest we break it into three
patches (a) Ensure the same inactive_since time for all slots, (b)
Raise an error for invalid slots during ReplicationSlotAcquire(); tell
in the commit message, without this patch when such an ERROR would
have otherwise occurred, and (c) Changes in
InvalidatePossiblyObsoleteSlot(), I suggest to leave this change for
later as this impacts the core logic of invalidation.

*
@@ -812,7 +823,7 @@ ReplicationSlotAlter(const char *name, const bool *failover,
  Assert(MyReplicationSlot == NULL);
  Assert(failover || two_phase);

- ReplicationSlotAcquire(name, false);
+ ReplicationSlotAcquire(name, false, false);

Why don't we want to give ERROR during Alter? I think it is okay to
not give ERROR for invalid slots during Drop as we are anyway removing
such slots.

--
With Regards,
Amit Kapila.