Clarify old WAL files cannot be removed until they are summarized

Started by Fujii Masaoover 1 year ago5 messagesdocs
Jump to latest
#1Fujii Masao
masao.fujii@gmail.com

Hi,

The documentation in wal.sgml explains that old WAL files cannot be
removed or recycled until they are archived (when WAL archiving is used)
or replicated (when using replication slots). However, it did not
mention that, similarly, old WAL files are also kept until they are summarized
if WAL summarization is enabled. Attached patch adds that clarification to
the documentation. Thought?

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

Attachments:

v1-0001-doc-Clarify-old-WAL-files-are-kept-until-they-are.patchtext/plain; charset=UTF-8; name=v1-0001-doc-Clarify-old-WAL-files-are-kept-until-they-are.patchDownload+2-1
#2Michael Paquier
michael@paquier.xyz
In reply to: Fujii Masao (#1)
Re: Clarify old WAL files cannot be removed until they are summarized

On Fri, Oct 18, 2024 at 02:25:15AM +0900, Fujii Masao wrote:

The documentation in wal.sgml explains that old WAL files cannot be
removed or recycled until they are archived (when WAL archiving is used)
or replicated (when using replication slots). However, it did not
mention that, similarly, old WAL files are also kept until they are summarized
if WAL summarization is enabled. Attached patch adds that clarification to
the documentation. Thought?

@@ -643,6 +643,8 @@
until the situation is resolved. A slow or failed standby server that
uses a replication slot will have the same effect (see
<xref linkend="streaming-replication-slots"/>).
+   Similarly, if WAL summarization is enabled, old segments are kept
+   until they are summarized.
</para>

Sounds like a good idea to me. I'd suggest to add a link to
runtime-config-wal-summarization as it is the first reference to WAL
summarization in this file.
--
Michael

#3Fujii Masao
masao.fujii@gmail.com
In reply to: Michael Paquier (#2)
Re: Clarify old WAL files cannot be removed until they are summarized

On 2024/12/11 9:18, Michael Paquier wrote:

On Fri, Oct 18, 2024 at 02:25:15AM +0900, Fujii Masao wrote:

The documentation in wal.sgml explains that old WAL files cannot be
removed or recycled until they are archived (when WAL archiving is used)
or replicated (when using replication slots). However, it did not
mention that, similarly, old WAL files are also kept until they are summarized
if WAL summarization is enabled. Attached patch adds that clarification to
the documentation. Thought?

@@ -643,6 +643,8 @@
until the situation is resolved. A slow or failed standby server that
uses a replication slot will have the same effect (see
<xref linkend="streaming-replication-slots"/>).
+   Similarly, if WAL summarization is enabled, old segments are kept
+   until they are summarized.
</para>

Sounds like a good idea to me. I'd suggest to add a link to
runtime-config-wal-summarization as it is the first reference to WAL
summarization in this file.

Yes, that sounds like a good idea. I've updated the patch accordingly.

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

Attachments:

v2-0001-doc-Clarify-old-WAL-files-are-kept-until-they-are.patchtext/plain; charset=UTF-8; name=v2-0001-doc-Clarify-old-WAL-files-are-kept-until-they-are.patchDownload+3-1
#4Michael Paquier
michael@paquier.xyz
In reply to: Fujii Masao (#3)
Re: Clarify old WAL files cannot be removed until they are summarized

On Fri, Dec 13, 2024 at 12:08:06AM +0900, Fujii Masao wrote:

Yes, that sounds like a good idea. I've updated the patch accordingly.

LGTM.
--
Michael

#5Fujii Masao
masao.fujii@gmail.com
In reply to: Michael Paquier (#4)
Re: Clarify old WAL files cannot be removed until they are summarized

On 2024/12/13 9:12, Michael Paquier wrote:

On Fri, Dec 13, 2024 at 12:08:06AM +0900, Fujii Masao wrote:

Yes, that sounds like a good idea. I've updated the patch accordingly.

LGTM.

Pushed. Thanks!

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION