pgpool2.git / summary / log / commit / refs
commit ba1e5ff4f276199ef5ab32ac318d8ea52626cd8f
Author: Tatsuo Ishii <ishii@sraoss.co.jp>
Date: Tue Nov 22 11:39:21 2022 +0000
Doc: enhance restrictions section.
Mention that failover_on_backend_shutdown can be used to avoid
unwanted failover caused by pg_terminate_backend.
doc.ja/src/sgml/restrictions.sgml | 16 +++++++++++-----
doc/src/sgml/restrictions.sgml | 13 +++++++++----
2 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/doc.ja/src/sgml/restrictions.sgml b/doc.ja/src/sgml/restrictions.sgml
index ff00f0b7c..7dced19de 100644
--- a/doc.ja/src/sgml/restrictions.sgml
+++ b/doc.ja/src/sgml/restrictions.sgml
@@ -18,26 +18,32 @@
<!--
<term>Functionality of PostgreSQL</term>
-->
- <term>PostgreSQLの機能</term>
+ <term>pg_terminate_backendの利用</term>
<listitem>
<para>
<!--
- If you use <function>pg_terminate_backend()</function> to stop
- a backend, this will trigger a failover. The reason why this
+ If you use <function>pg_terminate_backend()</function> to stop a
+ backend, this will trigger a failover. The reason why this
happens is that <productname>PostgreSQL</productname> sends
exactly the same message for a terminated backend as for a full
postmaster shutdown. There is no workaround prior of version
3.6. From version 3.6, this limitation has been mitigated. If
the argument to the function (that is a process id) is a
constant, you can safely use the function. In extended protocol
- mode, you cannot use the function though.
+ mode, you cannot use the function though. In 4.3 or later you
+ can completely prevent the failover caused
+ by <function>pg_terminate_backend()</function> by
+ setting <literal>off</literal>
+ to <xref linkend="guc-failover-on-backend-shutdown">, this will
+ prevent failover caused by termination of postmaster.
-->
<function>pg_terminate_backend()</function>を使ってバックエンドを停止すると、フェイルオーバが起こります。
これは、<productname>PostgreSQL</productname>が、postmasterの停止と全く同じメッセージをバックエンド停止時に送るためです。
- 3.6より前のバージョンには回避策はありません。
+ <productname>Pgpool-II</productname> 3.6より前のバージョンには回避策はありません。
3.6以降では、この制限は緩和されています。
その関数の引数（プロセスIDです）が定数なら、その関数を使っても安全です。
しかし、拡張プロトコルでは、その関数は使えません。
+ 4.3以降では、<xref linkend="guc-failover-on-backend-shutdown">を<literal>off</literal>にすることで、<function>pg_terminate_backend()</function>によるフェイルオーバを完全に回避できますが、その代わりpostmasterの停止によるフェイルオーバも起きなくなります。
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/restrictions.sgml b/doc/src/sgml/restrictions.sgml
index 6383d4549..e6b968b78 100644
--- a/doc/src/sgml/restrictions.sgml
+++ b/doc/src/sgml/restrictions.sgml
@@ -9,18 +9,23 @@
<variablelist>
<varlistentry>
- <term>Functionality of PostgreSQL</term>
+ <term>Using pg_terminate_backend</term>
<listitem>
<para>
- If you use <function>pg_terminate_backend()</function> to stop
- a backend, this will trigger a failover. The reason why this
+ If you use <function>pg_terminate_backend()</function> to stop a
+ backend, this will trigger a failover. The reason why this
happens is that <productname>PostgreSQL</productname> sends
exactly the same message for a terminated backend as for a full
postmaster shutdown. There is no workaround prior of version
3.6. From version 3.6, this limitation has been mitigated. If
the argument to the function (that is a process id) is a
constant, you can safely use the function. In extended protocol
- mode, you cannot use the function though.
+ mode, you cannot use the function though. In 4.3 or later you
+ can completely prevent the failover caused
+ by <function>pg_terminate_backend()</function> by
+ setting <literal>off</literal>
+ to <xref linkend="guc-failover-on-backend-shutdown">, this will
+ prevent failover caused by termination of postmaster though.
</para>
</listitem>
</varlistentry>
[parent: 1087ea8a4062]