On Wed, Oct 05, 2022 at 07:55:58PM +0200, Peter Eisentraut wrote:
> Leaving archive_command empty is an intentional configuration choice.
>
> What we are talking about here is, arguably, a misconfiguration, so it
> should result in an error.
Okay. What do you think about something like the attached?
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index d750290f13..bb4d985f35 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -3597,9 +3597,11 @@ include_dir 'conf.d'
</para>
<para>
This parameter can only be set in the <filename>postgresql.conf</filename>
- file or on the server command line. It is ignored unless
+ file or on the server command line. It is only used if
<varname>archive_mode</varname> was enabled at server start and
- <varname>archive_library</varname> is set to an empty string.
+ <varname>archive_library</varname> is set to an empty string. If both
+ <varname>archive_command</varname> and <varname>archive_library</varname>
+ are set, archiving will fail.
If <varname>archive_command</varname> is an empty string (the default) while
<varname>archive_mode</varname> is enabled (and <varname>archive_library</varname>
is set to an empty string), WAL archiving is temporarily
@@ -3624,7 +3626,9 @@ include_dir 'conf.d'
<para>
The library to use for archiving completed WAL file segments. If set to
an empty string (the default), archiving via shell is enabled, and
- <xref linkend="guc-archive-command"/> is used. Otherwise, the specified
+ <xref linkend="guc-archive-command"/> is used. If both
+ <varname>archive_command</varname> and <varname>archive_library</varname>
+ are set, archiving will fail. Otherwise, the specified
shared library is used for archiving. For more information, see
<xref linkend="backup-archiving-wal"/> and
<xref linkend="archive-modules"/>.
diff --git a/src/backend/postmaster/pgarch.c b/src/backend/postmaster/pgarch.c
index 3868cd7bd3..56dcc0dce5 100644
--- a/src/backend/postmaster/pgarch.c
+++ b/src/backend/postmaster/pgarch.c
@@ -838,6 +838,12 @@ LoadArchiveLibrary(void)
memset(&ArchiveContext, 0, sizeof(ArchiveModuleCallbacks));
+ if (XLogArchiveLibrary[0] != '\0' && XLogArchiveCommand[0] != '\0')
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("both archive_command and archive_library specified"),
+ errdetail("Only one of archive_command, archive_library may be set.")));
+
/*
* If shell archiving is enabled, use our special initialization function.
* Otherwise, load the library and call its _PG_archive_module_init().
