From ca3ecfd7ae8c63f3b8c6f7fa78ace36c4ffc10c5 Mon Sep 17 00:00:00 2001
From: Bo Peng <pengbo@sraoss.co.jp>
Date: Wed, 3 Apr 2024 16:18:17 +0900
Subject: [PATCH] Doc: enhance "Upstream server connection" documentation.

---
 doc.ja/src/sgml/watchdog.sgml        | 26 +++++++++++++++++++++++---
 doc/src/sgml/watchdog.sgml           | 15 ++++++++++++++-
 src/sample/pgpool.conf.sample-stream |  2 +-
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/doc.ja/src/sgml/watchdog.sgml b/doc.ja/src/sgml/watchdog.sgml
index 01562f12e..fae4f98cf 100644
--- a/doc.ja/src/sgml/watchdog.sgml
+++ b/doc.ja/src/sgml/watchdog.sgml
@@ -286,7 +286,24 @@
   <!--
   <title>Upstream server connection</title>
   -->
-  <title>上流サーバへの接続</title>
+  <title>上位サーバへの接続</title>
+
+  <para>
+   <!--
+   Upstream servers are the clients (DB clients) served by
+   <productname>Pgpool-II</productname>.
+   Even if <productname>Pgpool-II</productname> is alive and
+   connected to <productname>PostgreSQL</productname>, 
+   if the link with the upstream server is broken,
+   <productname>Pgpool-II</productname> cannot provide services.
+   Therefore, the watchdog also monitors connections to upstream servers
+   from the <productname>Pgpool-II</productname>.
+   -->
+   <productname>Pgpool-II</productname>のサービス提供先（DB クライアント）のサーバを上位サーバと呼びます。 
+   <productname>Pgpool-II</productname>が生きていて<productname>PostgreSQL</productname>と繋がっている場合でも、
+   上位サーバとのリンクが切れていれば、<productname>Pgpool-II</productname>はサービスを提供できません。
+   そのため、watchdogは上位サーバとのリンクが繋がっているかどうかも監視します。
+  </para>
 
   <variablelist>
 
@@ -302,7 +319,9 @@
     <listitem>
      <para>
       <!--
-      Specifies the list of trusted servers to check the up stream connections.
+      Specifies the list of trusted servers to check the upstream connections.
+      For example, a list of upstream servers or routers between
+      <productname>Pgpool-II</productname> and upstream servers.
       Each server in the list is required to respond to ping.
       Specify a comma separated list of servers such as
       <literal>"hostA,hostB,hostC"</literal>.
@@ -311,7 +330,8 @@
       Therefore, it is recommended to specify multiple servers.
       Please note that you should not assign PostgreSQL servers to this parameter.
       -->
-      上位接続を確認するための信頼できるサーバのリストを指定します。
+      上位サーバとの接続を確認するための信頼できるサーバのリストを指定します。
+      例えば、上位サーバ、あるいは上位サーバへの経路上にあるルーターのリストを指定します。
       リスト中の各サーバは、pingの応答に答える必要があります。
       <literal>"hostA,hostB,hostC"</literal>のようにカンマで区切って複数のサーバを指定できます。
       全てのサーバに到達できなくなると、watchdogは<productname>Pgpool-II</productname>に障害が発生したと判断します。
diff --git a/doc/src/sgml/watchdog.sgml b/doc/src/sgml/watchdog.sgml
index 5f8512a21..4c85dbec0 100644
--- a/doc/src/sgml/watchdog.sgml
+++ b/doc/src/sgml/watchdog.sgml
@@ -207,6 +207,17 @@ pgpool_port2 = 9999
  <sect2 id="config-watchdog-upstream-connections">
   <title>Upstream server connection</title>
 
+  <para>
+   Upstream servers are the clients (DB clients) served by
+   <productname>Pgpool-II</productname>.
+   Even if <productname>Pgpool-II</productname> is alive and
+   connected to <productname>PostgreSQL</productname>, 
+   if the link with the upstream server is broken,
+   <productname>Pgpool-II</productname> cannot provide services.
+   Therefore, the watchdog also monitors connections to upstream servers
+   from the <productname>Pgpool-II</productname>.
+  </para>
+
   <variablelist>
 
    <varlistentry id="guc-trusted-servers" xreflabel="trusted_servers">
@@ -217,7 +228,9 @@ pgpool_port2 = 9999
     </term>
     <listitem>
      <para>
-      Specifies the list of trusted servers to check the up stream connections.
+      Specifies the list of trusted servers to check the upstream connections.
+      For example, the list of upstream servers or routers between
+      <productname>Pgpool-II</productname> and upstream servers.
       Each server in the list is required to respond to ping.
       Specify a comma separated list of servers such as
       <literal>"hostA,hostB,hostC"</literal>.
diff --git a/src/sample/pgpool.conf.sample-stream b/src/sample/pgpool.conf.sample-stream
index fbe7fc827..1b0756172 100644
--- a/src/sample/pgpool.conf.sample-stream
+++ b/src/sample/pgpool.conf.sample-stream
@@ -694,7 +694,7 @@ backend_clustering_mode = 'streaming_replication'
                                     # Activates watchdog
                                     # (change requires restart)
 
-# -Connection to up stream servers -
+# -Connection to upstream servers -
 
 #trusted_servers = ''
                                     # trusted server list which are used
-- 
2.39.5