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

On Wed, Sep 4, 2024 at 2:49 PM shveta malik <shveta.malik@gmail.com> wrote:
>
> On Wed, Sep 4, 2024 at 9:17 AM shveta malik <shveta.malik@gmail.com> wrote:
> >
> > On Tue, Sep 3, 2024 at 3:01 PM shveta malik <shveta.malik@gmail.com> wrote:
> > >
> > >
>
>
> 1)
> It is related to one of my previous comments (pt 3 in [1]) where I
> stated that inactive_since should not keep on changing once a slot is
> invalidated.
>

Agreed. Updating the inactive_since for a slot that is already invalid
is misleading.

>
>
> 2)
> One more issue in this message is, once I set
> replication_slot_inactive_timeout to a bigger value, it becomes more
> misleading. This is because invalidation was done in the past using
> previous value while message starts showing new value:
>
> ALTER SYSTEM SET replication_slot_inactive_timeout TO '36h';
>
> --see 129600 secs in DETAIL and the current time.
> postgres=# SELECT * FROM pg_replication_slot_advance('mysubnew1_1',
> pg_current_wal_lsn());
> ERROR:  can no longer get changes from replication slot "mysubnew1_1"
> DETAIL:  The slot became invalid because it was inactive since
> 2024-09-04 10:06:38.980939+05:30, which is more than 129600 seconds
> ago.
> postgres=# select now();
>                now
> ----------------------------------
>  2024-09-04 10:07:35.201894+05:30
>
> I feel we should change this message itself.
>

+1.

--
With Regards,
Amit Kapila.