Test replay of regression tests.

Add a new TAP test under src/test/recovery to run the standard
regression tests while a streaming replica replays the WAL.  This
provides a basic workout for WAL decoding and redo code, and compares
the replicated result.

Optionally, enable (expensive) wal_consistency_checking if listed in
the env variable PG_TEST_EXTRA.

Reviewed-by: 綱川 貴之 (Takayuki Tsunakawa) <tsunakawa.takay@fujitsu.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Anastasia Lubennikova <lubennikovaav@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA%2BhUKGKpRWQ9SxdxxDmTBCJoR0YnFpMBe7kyzY8SUQk%2BHeskxg%40mail.gmail.com

doc/src/sgml/regress.sgml

@@ -289,6 +289,17 @@ make check-world PG_TEST_EXTRA='kerberos ldap ssl'
       </para>
      </listitem>
     </varlistentry>
+
+    <varlistentry>
+     <term><literal>wal_consistency_checking</literal></term>
+     <listitem>
+      <para>
+       Uses <literal>wal_consistency_checking=all</literal> while running
+       certain tests under <filename>src/test/recovery</filename>.  Not
+       enabled by default because it is resource intensive.
+      </para>
+     </listitem>
+    </varlistentry>
    </variablelist>
 
    Tests for features that are not supported by the current build

src/test/recovery/Makefile

@@ -15,10 +15,14 @@ subdir = src/test/recovery
 top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
-# required for 017_shm.pl
+# required for 017_shm.pl and 027_stream_regress.pl
 REGRESS_SHLIB=$(abs_top_builddir)/src/test/regress/regress$(DLSUFFIX)
 export REGRESS_SHLIB
 
+# required for 027_stream_regress.pl
+REGRESS_OUTPUTDIR=$(abs_top_builddir)/src/test/recovery
+export REGRESS_OUTPUTDIR
+
 check:
 	$(prove_check)
 

src/test/recovery/t/027_stream_regress.pl

@@ -0,0 +1,80 @@
+# Run the standard regression tests with streaming replication
+use strict;
+use warnings;
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More tests => 4;
+use File::Basename;
+
+# Initialize primary node
+my $node_primary = PostgreSQL::Test::Cluster->new('primary');
+$node_primary->init(allows_streaming => 1);
+$node_primary->adjust_conf('postgresql.conf', 'max_connections', '25', 1);
+$node_primary->append_conf('postgresql.conf', 'max_prepared_transactions = 10');
+
+# WAL consistency checking is resource intensive so require opt-in with the
+# PG_TEST_EXTRA environment variable.
+if ($ENV{PG_TEST_EXTRA} &&
+	$ENV{PG_TEST_EXTRA} =~ m/\bwal_consistency_checking\b/) {
+	$node_primary->append_conf('postgresql.conf',
+		'wal_consistency_checking = all');
+}
+
+$node_primary->start;
+is( $node_primary->psql(
+        'postgres',
+        qq[SELECT pg_create_physical_replication_slot('standby_1');]),
+    0,
+    'physical slot created on primary');
+my $backup_name = 'my_backup';
+
+# Take backup
+$node_primary->backup($backup_name);
+
+# Create streaming standby linking to primary
+my $node_standby_1 = PostgreSQL::Test::Cluster->new('standby_1');
+$node_standby_1->init_from_backup($node_primary, $backup_name,
+	has_streaming => 1);
+$node_standby_1->append_conf('postgresql.conf',
+    "primary_slot_name = standby_1");
+$node_standby_1->start;
+
+my $dlpath = PostgreSQL::Test::Utils::perl2host(dirname($ENV{REGRESS_SHLIB}));
+my $outputdir = PostgreSQL::Test::Utils::perl2host($ENV{REGRESS_OUTPUTDIR});
+
+# Run the regression tests against the primary.
+my $extra_opts = $ENV{EXTRA_REGRESS_OPTS} || "";
+system_or_bail($ENV{PG_REGRESS} . " " .
+			   "--dlpath=\"$dlpath\" " .
+			   "--bindir= " .
+			   "--port=" . $node_primary->port . " " .
+			   "--schedule=../regress/parallel_schedule " .
+			   "--max-concurrent-tests=20 " .
+			   "--inputdir=../regress " .
+			   "--outputdir=\"$outputdir\" " .
+			   $extra_opts);
+
+# Clobber all sequences with their next value, so that we don't have
+# differences between nodes due to caching.
+$node_primary->psql('regression',
+	"select setval(seqrelid, nextval(seqrelid)) from pg_sequence");
+
+# Wait for standby to catch up
+$node_primary->wait_for_catchup($node_standby_1, 'replay',
+	$node_primary->lsn('insert'));
+
+# Perform a logical dump of primary and standby, and check that they match
+command_ok(
+	[ 'pg_dumpall', '-f', $outputdir . '/primary.dump', '--no-sync',
+	  '-p', $node_primary->port ],
+	'dump primary server');
+command_ok(
+	[ 'pg_dumpall', '-f', $outputdir . '/standby.dump', '--no-sync',
+	  '-p', $node_standby_1->port ],
+	'dump standby server');
+command_ok(
+	[ 'diff', $outputdir . '/primary.dump', $outputdir . '/standby.dump' ],
+	'compare primary and standby dumps');
+
+$node_standby_1->stop;
+$node_primary->stop;

src/tools/msvc/vcregress.pl

@@ -536,6 +536,8 @@ sub recoverycheck
 {
 	InstallTemp();
 
+	$ENV{REGRESS_OUTPUTDIR} = "$topdir/src/test/recovery";
+
 	my $mstat  = 0;
 	my $dir    = "$topdir/src/test/recovery";
 	my $status = tap_check($dir);