On 2025/06/26 15:43, Hayato Kuroda (Fujitsu) wrote:
Dear Fujii-san,
The pg_replication_slots documentation mentions only max_slot_wal_keep_size
as a condition under which the wal_status column can show unreserved or lost.
However, since commit ac0e33136ab, idle_replication_slot_timeout can also
cause this behavior when it is set. This has not been documented yet.
https://www.postgresql.org/docs/devel/view-pg-replication-slots.html
Oh, I feel the doc should be also updated.
Thanks for the review!
So, how about updating the documentation to also mention
idle_replication_slot_timeout as a factor that can cause wal_status to
become unreserved or lost? Patch attached.
One comment:
```
<para>
<literal>lost</literal> means that some required WAL files have
been removed and this slot is no longer usable.
</para>
```
IIUC, there is a case that status is "lost" but the required WALs have not been
dropped yet if the slot was invalidated due to the timeout. How about removing
the
first part:
```
<literal>lost</literal> means that this slot is no longer usable.
```
Agreed. Attached is the updated version of the patch.
Regards,
--
Fujii Masao
NTT DATA Japan Corporation
From a730908764b2255fd7ab36441417bddc643d4a5e Mon Sep 17 00:00:00 2001
From: Fujii Masao <fu...@postgresql.org>
Date: Thu, 26 Jun 2025 16:49:59 +0900
Subject: [PATCH v2] doc: Mention idle_replication_slot_timeout in
pg_replication_slots docs.
The pg_replication_slots documentation previously mentioned only
max_slot_wal_keep_size as a condition under which the wal_status column
can show unreserved or lost. However, since commit ac0e33136ab,
idle_replication_slot_timeout can also cause this behavior when it is set.
This was not documented.
This commit updates the documentation to also mention
idle_replication_slot_timeout as a factor that can cause wal_status
to become unreserved or lost.
Author: Fujii Masao <masao.fu...@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hay...@fujitsu.com>
Reviewed-by: Nisha Moond <nisha.moond...@gmail.com>
Discussion:
https://postgr.es/m/78b34e84-2195-4f28-a151-5d204a382...@oss.nttdata.com
---
doc/src/sgml/system-views.sgml | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml
index 986ae1f543d..308e5dabf3b 100644
--- a/doc/src/sgml/system-views.sgml
+++ b/doc/src/sgml/system-views.sgml
@@ -2825,15 +2825,15 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts
ppx
</listitem>
<listitem>
<para>
- <literal>lost</literal> means that some required WAL files have
- been removed and this slot is no longer usable.
+ <literal>lost</literal> means that this slot is no longer usable.
</para>
</listitem>
</itemizedlist>
The last two states are seen only when
<xref linkend="guc-max-slot-wal-keep-size"/> is
- non-negative. If <structfield>restart_lsn</structfield> is NULL, this
- field is null.
+ non-negative and/or <xref linkend="guc-idle-replication-slot-timeout"/>
+ is greater than zero. If <structfield>restart_lsn</structfield> is NULL,
+ this field is null.
</para></entry>
</row>
--
2.49.0
