On 2024/09/17 11:47, Fujii Masao wrote:
On 2024/09/16 23:30, Anton A. Melnikov wrote:
+1
This idea seems quite tenable to me.
There is a small clarification. Now if there were no skipped restartpoints then
restartpoints_done will be equal to restartpoints_timed + restartpoints_req.
Similar for checkpoints.
So i tried to introduce num_done counter for checkpoints in the patch attached.
Thanks for the patch! I believe this change is targeted for v18. For v17,
however,
we should update the description of num_timed in the documentation. Thought?
Here's a suggestion:
"Number of scheduled checkpoints due to timeout. Note that checkpoints may be
skipped if the server has been idle since the last one, and this value counts
both completed and skipped checkpoints."
Patch attached.
Unless there are any objections, I plan to commit this and back-patch it to v17.
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
From 96dd9e0f923aef44ee1d73ea2bafea8d9db805bf Mon Sep 17 00:00:00 2001
From: Fujii Masao <fu...@postgresql.org>
Date: Wed, 18 Sep 2024 19:03:53 +0900
Subject: [PATCH v1] docs: Improve the description of num_timed column in
pg_stat_checkpointer.
The previous documentation stated that num_timed reflects the number of
scheduled checkpoints performed. However, checkpoints may be skipped
if the server has been idle, and num_timed counts both skipped and completed
checkpoints. This commit clarifies the description to make it clear that
the counter includes both skipped and completed checkpoints.
Back-patch to v17 where pg_stat_checkpointer was added.
Discussion:
https://postgr.es/m/9ea77f40-818d-4841-9dee-158ac8f6e...@oss.nttdata.com
---
doc/src/sgml/monitoring.sgml | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 933de6fe07..a2fda4677d 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -3051,7 +3051,10 @@ description | Waiting for a newly initialized WAL file
to reach durable storage
<structfield>num_timed</structfield> <type>bigint</type>
</para>
<para>
- Number of scheduled checkpoints that have been performed
+ Number of scheduled checkpoints due to timeout.
+ Note that checkpoints may be skipped if the server has been idle
+ since the last one, and this value counts both completed and
+ skipped checkpoints
</para></entry>
</row>
--
2.45.2
