Reply-To: jesper.pedersen@redhat.com
Subject: Re: pg_receivewal documentation
To: Michael Paquier <michael@paquier.xyz>
Cc: Laurenz Albe <laurenz.albe@cybertec.at>,
 Alvaro Herrera <alvherre@2ndquadrant.com>,
 PostgreSQL-development <pgsql-hackers@postgresql.org>
References: <20190710142421.GA28387@alvherre.pgsql>
 <54779de5-f922-c0cf-629d-b582eded7265@redhat.com>
 <20190716050555.GA1439@paquier.xyz>
 <ebed4b9043b222d486ea3f0e44e7dcd242a80781.camel@cybertec.at>
 <65c3ecdf-8995-34cb-83c4-50068877e632@redhat.com>
 <20190717013835.GA2130@paquier.xyz>
 <44e51f9f60abb872854879c91da0ed3b67a6ba95.camel@cybertec.at>
 <20190717080424.GB20614@paquier.xyz>
 <7eaf748c-3f40-c994-0eb3-7d87709588d0@redhat.com>
 <184780f1f90a31c4c8b53f0e6328bf5aaae4f786.camel@cybertec.at>
 <20190718052909.GF1416@paquier.xyz>
From: Jesper Pedersen <jesper.pedersen@redhat.com>
Organization: Red Hat
Message-ID: <fd10372f-1cc9-3068-8088-c5da27a28bf7@redhat.com>
Date: Thu, 18 Jul 2019 08:40:36 -0400
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Hi,

On 7/18/19 1:29 AM, Michael Paquier wrote:
> Or more simply like that?
> "Note that while WAL will be flushed with this setting,
> pg_receivewal never applies it, so synchronous_commit must not be set
> to remote_apply if pg_receivewal is a synchronous standby, be it a
> member of a priority-based (FIRST) or a quorum-based (ANY) synchronous
> replication setup."

Yeah, better.

Best regards,
  Jesper


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From 2bcb8d6376d94a265a598f552eed3915b980aa94 Mon Sep 17 00:00:00 2001
From: jesperpedersen <jesper.pedersen@redhat.com>
Date: Tue, 9 Jul 2019 13:14:25 -0400
Subject: [PATCH] Highlight that pg_receivewal doesn't apply WAL, and as such
 synchronous-commit needs to be remote_write or lower.
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Authors: Michael Paquier, Álvaro Herrera, Laurenz Albe and Jesper Pedersen
Review-by: Michael Paquier, Álvaro Herrera, Laurenz Albe and Jesper Pedersen
---
 doc/src/sgml/ref/pg_receivewal.sgml | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/doc/src/sgml/ref/pg_receivewal.sgml b/doc/src/sgml/ref/pg_receivewal.sgml
index 0506120c00..e96d753955 100644
--- a/doc/src/sgml/ref/pg_receivewal.sgml
+++ b/doc/src/sgml/ref/pg_receivewal.sgml
@@ -207,6 +207,16 @@ PostgreSQL documentation
         server as a synchronous standby, to ensure that timely feedback is
         sent to the server.
        </para>
+
+       <para>
+        Note that while WAL will be flushed with this setting,
+        <application>pg_receivewal</application> never applies it,
+        so <xref linkend="guc-synchronous-commit"/> must not be set
+        to <literal>remote_apply</literal> or <literal>on</literal> if
+        <application>pg_receivewal</application> is a synchronous standby, be it a
+        member of a priority-based (<literal>FIRST</literal>) or a
+        quorum-based (<literal>ANY</literal>) synchronous replication setup.
+       </para>
       </listitem>
      </varlistentry>
 
-- 
2.21.0


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