Re: Slot's restart_lsn may point to removed WAL segment after hard restart unexpectedly

Masahiko Sawada <sawada.mshk@gmail.com>

From: Masahiko Sawada <sawada.mshk@gmail.com>

To: Alexander Korotkov <aekorotkov@gmail.com>

Cc: Vitaly Davydov <v.davydov@postgrespro.ru>, pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2025-04-29T01:02:55Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Update comment for ReplicationSlot.last_saved_restart_lsn
- 0810fbb02dbe 19 (unreleased) landed
Fix CheckPointReplicationSlots() with max_replication_slots == 0
- 7195c804bd12 18.0 landed
Remove excess assert from InvalidatePossiblyObsoleteSlot()
- 70d8a91f82f1 18.0 landed
Improve runtime and output of tests for replication slots checkpointing.
- 5ed50f9386f0 17.6 landed
- 4464fddf7b50 18.0 landed
Keep WAL segments by slot's last saved restart LSN
- ca307d5cec90 18.0 landed
Fix an assert in CheckPointReplicationSlots().
- d1ffcc7fa3c5 17.0 cited

On Mon, Apr 28, 2025 at 8:17 AM Alexander Korotkov <aekorotkov@gmail.com> wrote:
>
> > I have a question - is there any interest to backport the solution into
> > existing major releases?
>
> As long as this is the bug, it should be backpatched to all supported
> affected releases.

Yes, but I think we cannot back-patch the proposed fix to back
branches as it changes the ReplicationSlot struct defined in slot.h,
which breaks ABI compatibility.

Regards,

-- 
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com