Hi,
Am Dienstag, den 14.02.2017, 18:18 -0500 schrieb Robert Haas:
> On Tue, Feb 14, 2017 at 4:06 PM, Alvaro Herrera
> <alvhe...@2ndquadrant.com> wrote:
> > I'd rather have a --quiet mode instead. If you're running it by hand,
> > you're likely to omit the switch, whereas when writing the cron job
> > you're going to notice lack of switch even before you let the job run
> > once.
>
> Well, that might've been a better way to design it, but changing it
> now would break backward compatibility and I'm not really sure that's
> a good idea. Even if it is, it's a separate concern from whether or
> not in the less-quiet mode we should point out that we're waiting for
> a checkpoint on the server side.
ISTM the consensus is that there should be no output in regular mode,
but a message should be displayed in verbose and progress mode.
So I went forth and also added a message in progress mode (unless
verbose messages are requested anyway).
Regarding the documentation, I tried to clarify the difference between
the checkpoint types a bit more, but I think any further action is
probably a larger rewrite of the documentation on this topic.
So attached are two patches, I've split it up in the documentation and
the code output part. I'll add it as one commitfest entry in the
"Clients" section though, as it's not really a big patch, unless
somebody thinks it should have a secon entry in "Documentation"?
Michael
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Michael Banck
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Tel.: +49 2166 9901-171
Fax: +49 2166 9901-100
Email: michael.ba...@credativ.de
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From bcbe19855f9f94eadf9e47a7f3b9a920a7f2a616 Mon Sep 17 00:00:00 2001
From: Michael Banck <michael.ba...@credativ.de>
Date: Sun, 26 Feb 2017 18:06:40 +0100
Subject: [PATCH 1/2] Documentation updates regarding checkpoints for
basebackups.
Mention that fast and immediate checkpoints are the same, and add a paragraph to
the pg_basebackup documentation about the checkpoint taken on the remote server.
---
doc/src/sgml/backup.sgml | 3 ++-
doc/src/sgml/ref/pg_basebackup.sgml | 10 +++++++++-
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
index 5f009ee..9485d87 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 possible.
</para>
<para>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index c9dd62c..c197630 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -419,7 +419,7 @@ 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>
@@ -660,6 +660,14 @@ PostgreSQL documentation
<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 idle on the
+ server it is running on.
+ </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
directory by third parties, except certain temporary files managed by
--
2.1.4
From 1e4051dff9710382b6b4f63373a304c6ce70c4ac Mon Sep 17 00:00:00 2001
From: Michael Banck <michael.ba...@credativ.de>
Date: Sun, 26 Feb 2017 20:23:21 +0100
Subject: [PATCH 2/2] Mention initial checkpoint in pg_basebackup for
verbose/progess output.
Before the actual data directory contents are streamed, a checkpoint is
taken on the remote server. Especially if no fast checkpoint is
requested, this can take quite a while during which the pg_basebackup
command apparently sits idle doing nothing.
To alert the user that work is being done on the remote server, mention
the checkpoint if verbose or progress output has been requested. As
pg_basebackup does not output anything during regular operation, no
additional output is printed in this case.
Also harmonize some other verbose messages in passing.
---
src/bin/pg_basebackup/pg_basebackup.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index bc997dc..4b75e76 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -1753,6 +1753,14 @@ 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\n");
+
basebkp =
psprintf("BASE_BACKUP LABEL '%s' %s %s %s %s %s %s",
escaped_label,
@@ -1790,6 +1798,9 @@ 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
@@ -1803,8 +1814,8 @@ BaseBackup(void)
MemSet(xlogend, 0, sizeof(xlogend));
if (verbose && includewal != NO_WAL)
- fprintf(stderr, _("transaction log start point: %s on timeline %u\n"),
- xlogstart, starttli);
+ fprintf(stderr, _("%s: transaction log start point: %s on timeline %u\n"),
+ progname, xlogstart, starttli);
/*
* Get the header
@@ -1906,7 +1917,7 @@ BaseBackup(void)
}
strlcpy(xlogend, PQgetvalue(res, 0, 0), sizeof(xlogend));
if (verbose && includewal != NO_WAL)
- fprintf(stderr, "transaction log end point: %s\n", xlogend);
+ fprintf(stderr, _("%s: transaction log end point: %s\n"), progname, xlogend);
PQclear(res);
res = PQgetResult(conn);
@@ -2047,7 +2058,7 @@ BaseBackup(void)
}
if (verbose)
- fprintf(stderr, "%s: base backup completed\n", progname);
+ fprintf(stderr, _("%s: base backup completed\n"), progname);
}
--
2.1.4
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