Date: Wed, 14 Sep 2022 14:09:33 -0700
From: Nathan Bossart <nathandbossart@gmail.com>
To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Cc: Michael Paquier <michael@paquier.xyz>,
	Robert Haas <robertmhaas@gmail.com>,
	"Bossart, Nathan" <bossartn@amazon.com>,
	David Steele <david@pgmasters.net>,
	Fujii Masao <masao.fujii@oss.nttdata.com>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>,
	Magnus Hagander <magnus@hagander.net>,
	Stephen Frost <sfrost@snowman.net>
Subject: Re: archive modules
Message-ID: <20220914210933.GB2984249@nathanxps13>
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On Wed, Sep 14, 2022 at 09:31:04PM +0200, Peter Eisentraut wrote:
> Here is a patch that addresses this.

My intent was to present archive_command as the built-in archive library,
but I can see how this might cause confusion, so this change seems
reasonable to me.

> +   <para>
> +    It is important that the archive command return zero exit status if and
> +    only if it succeeds.  Upon getting a zero result,
> +    <productname>PostgreSQL</productname> will assume that the file has been
> +    successfully archived, and will remove or recycle it.  However, a nonzero
> +    status tells <productname>PostgreSQL</productname> that the file was not archived;
> +    it will try again periodically until it succeeds.
> +   </para>
> +
> +   <para>
> +    When the archive command is terminated by a signal (other than
> +    <systemitem>SIGTERM</systemitem> that is used as part of a server
> +    shutdown) or an error by the shell with an exit status greater than
> +    125 (such as command not found), the archiver process aborts and gets
> +    restarted by the postmaster. In such cases, the failure is
> +    not reported in <xref linkend="pg-stat-archiver-view"/>.
> +   </para>

This wording is very similar to the existing wording in the archive library
section below it.  I think the second paragraph covers the shell command case
explicitly, too.  Perhaps these should be combined.

> +        <varname>archive_mode</varname> and <varname>archive_command</varname> are
> +        separate variables so that <varname>archive_command</varname> can be
> +        changed without leaving archiving mode.

I believe this applies to archive_library, too.

> -   for segments to complete like <xref linkend="guc-archive-library"/> does.
> +   for segments to complete like <xref linkend="guc-archive-command"/> and
> +   <xref linkend="guc-archive-library"/> does.

nitpick: s/does/do

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com