Re: pg_receivewal documentation

[Jesper Pedersen]

Hi,

On 7/10/19 10:24 AM, Alvaro Herrera wrote:

+1 to document this caveat.

How about
         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> if 
<application>pg_receivewal</application>
         is the only synchronous standby.
?

Sure.

Best regards,
 Jesper

>From cc51d52b2f67b33cd0faba1a74e05e93fc859011 Mon Sep 17 00:00:00 2001
From: jesperpedersen <jesper.peder...@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.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Authors: Álvaro Herrera, Laurenz Albe and Jesper Pedersen
Review-by: Álvaro Herrera, Laurenz Albe and Jesper Pedersen
---
 doc/src/sgml/ref/pg_receivewal.sgml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/doc/src/sgml/ref/pg_receivewal.sgml b/doc/src/sgml/ref/pg_receivewal.sgml
index 0506120c00..16f9c41ff1 100644
--- a/doc/src/sgml/ref/pg_receivewal.sgml
+++ b/doc/src/sgml/ref/pg_receivewal.sgml
@@ -207,6 +207,14 @@ 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> if <application>pg_receivewal</application>
+        is the only synchronous standby.
+       </para>
       </listitem>
      </varlistentry>
 
-- 
2.21.0