Re: Synchronizing slots from primary to standby

On Thu, Apr 4, 2024 at 2:59 PM shveta malik <shveta.malik@gmail.com> wrote:
>
>
> Prior to commit 2ec005b, this check was okay, as we did not expect
> restart_lsn of the synced slot to be ahead of remote since we were
> directly copying the lsns. But now when we use 'advance' to do logical
> decoding on standby, there is a possibility that restart lsn of the
> synced slot is ahead of remote slot, if there are running txns records
> found after reaching consistent-point while consuming WALs from
> restart_lsn till confirmed_lsn. In such a case, slot-sync's advance
> may end up serializing snapshots and setting restart_lsn to the
> serialized snapshot point, ahead of remote one.
>
> Fix:
> The sanity check needs to be corrected. Attached a patch to address the issue.

Please find v2 which has detailed commit-msg and some more comments in code.

thanks
Shveta