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

Alexander Korotkov <aekorotkov@gmail.com>

From: Alexander Korotkov <aekorotkov@gmail.com>

To: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>

Cc: Tom Lane <tgl@sss.pgh.pa.us>, Alexander Lakhin <exclusion@gmail.com>, Vitaly Davydov <v.davydov@postgrespro.ru>, Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, Masahiko Sawada <sawada.mshk@gmail.com>, "tomas@vondra.me" <tomas@vondra.me>

Date: 2025-06-16T11:16:42Z

Lists: pgsql-hackers

Commits

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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

Attachments

v3-0001-Improve-runtime-and-output-of-tests-for-replicati.patch (application/octet-stream) patch v3-0001

Dear Kuroda-san,

On Mon, Jun 16, 2025 at 12:11 PM Hayato Kuroda (Fujitsu)
<kuroda.hayato@fujitsu.com> wrote:
> Thanks for pushing the fix patch! BTW, I have few comments for your commits.
> Can you check and include them if needed?
>
> 01.
> ```
> $node->append_conf('postgresql.conf',
>         "shared_preload_libraries = 'injection_points'");
> ```
>
> No need to set shared_preload_libraries in 046/047. ISTM it must be set when we
> enable the statistics.
>
> 02.
> We should also check whether the injection_points can be installed or not.
> You can check check_extension() and callers.

Thank you!  All of these totally make sense.  The updated patch is attached.

------
Regards,
Alexander Korotkov
Supabase