From b88b929a707145964b707257049f8dbfd58f0da5 Mon Sep 17 00:00:00 2001
From: Magnus Hagander <magnus@hagander.net>
Date: Sat, 1 Apr 2017 17:20:05 +0200
Subject: [PATCH] Back-patch checkpoint clarification docs and pg_basebackup
 updates

This backpatches 51e26c9 and 7220c7b, including both documentation
updates clarifying the checkpoints at the beginning of base backups and
the messages in verbose and progress mdoe of pg_basebackup.

Author: Michael Banck
Discussion: https://postgr.es/m/21444.1488142764%40sss.pgh.pa.us
---
 doc/src/sgml/backup.sgml              |  3 ++-
 doc/src/sgml/ref/pg_basebackup.sgml   | 10 +++++++++-
 src/bin/pg_basebackup/pg_basebackup.c | 11 +++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
index 8c0bb1f6a20..03c0dbf1cd0 100644
--- a/doc/src/sgml/backup.sgml
+++ b/doc/src/sgml/backup.sgml
@@ -862,7 +862,8 @@ SELECT pg_start_backup('label', false, false);
      <xref linkend="guc-checkpoint-completion-target">).  This is
      usually what you want, because it minimizes the impact on query
      processing.  If you want to start the backup as soon as
-     possible, change the second parameter to <literal>true</>.
+     possible, change the second parameter to <literal>true</>, which will
+     issue an immediate checkpoint using as much I/O as available.
     </para>
 
     <para>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 95c801627b3..134b2982368 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -382,7 +382,7 @@ PostgreSQL documentation
       <term><option>--checkpoint=<replaceable class="parameter">fast|spread</replaceable></option></term>
       <listitem>
        <para>
-        Sets checkpoint mode to fast or spread (default) (see <xref linkend="backup-lowlevel-base-backup">).
+        Sets checkpoint mode to fast (immediate) or spread (default) (see <xref linkend="backup-lowlevel-base-backup">).
        </para>
       </listitem>
      </varlistentry>
@@ -589,6 +589,14 @@ PostgreSQL documentation
  <refsect1>
   <title>Notes</title>
 
+  <para>
+   At the beginning of the backup, a checkpoint needs to be written on the
+   server the backup is taken from.  Especially if the option
+   <literal>--checkpoint=fast</literal> is not used, this can take some time
+   during which <application>pg_basebackup</application> will be appear
+   to be idle.
+  </para>
+
   <para>
    The backup will include all files in the data directory and tablespaces,
    including the configuration files and any additional files placed in the
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index a5bc3225337..613f2e159c3 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -1661,6 +1661,14 @@ BaseBackup(void)
 	if (maxrate > 0)
 		maxrate_clause = psprintf("MAX_RATE %u", maxrate);
 
+	if (verbose)
+		fprintf(stderr,
+				_("%s: initiating base backup, waiting for checkpoint to complete\n"),
+				progname);
+
+	if (showprogress && !verbose)
+		fprintf(stderr, "waiting for checkpoint\r");
+
 	basebkp =
 		psprintf("BASE_BACKUP LABEL '%s' %s %s %s %s %s %s",
 				 escaped_label,
@@ -1698,6 +1706,9 @@ BaseBackup(void)
 
 	strlcpy(xlogstart, PQgetvalue(res, 0, 0), sizeof(xlogstart));
 
+	if (verbose)
+		fprintf(stderr, _("%s: checkpoint completed\n"), progname);
+
 	/*
 	 * 9.3 and later sends the TLI of the starting point. With older servers,
 	 * assume it's the same as the latest timeline reported by
-- 
2.39.5