On Tue, May 25, 2021 at 9:16 PM Robert Haas <robertmh...@gmail.com> wrote:
> use FindBin;
>
> and then use $FindBin::RealBin to construct a path name to the executable,
> e.g.
>
> $node_primary->append_conf(
> 'postgresql.conf', qq(
> archive_command = '"$FindBin::RealBin/skip_cp" "%p" "$archivedir_primary/%f"'
> ));
>
> This avoids issues such as: leaving behind files if the script is
> terminated, needing the current working directory to be writable,
> possible permissions issues with the new file under Windows or
> SE-Linux.
Done
> The restore_command needs to be "cp" on Linux but "copy" on Windows.
> Maybe you can use PostgresNode.pm's enable_restoring? Or if that
> doesn't work, then you need to mimic the logic, as
> src/test/recovery/t/020_archive_status.pl does for archive_command.
Done
> Why do you set log_line_prefix? Is that needed?
No, it was not, removed
> Why are the nodes called standby_1 and cascade? Either use standby and
> cascade or standby_1 and standby_2.
Fixed
> There is a comment that says "Create some content on primary and check
> its presence in standby 1" but it only creates the content, and does
> not check anything. I think we don't really need to do any of this,
> but at least the code and the comment have to match.
I think we need to create some content on promoted standby and check
whether the cascade standby is able to get that or not, that will
guarantee that it is actually following the promoted standby, I have
added the test for that so that it matches the comments.
> Let's not call the command skip_cp. It's not very descriptive. If you
> don't like recalcitrant_cp, then maybe something like cp_history_files
> or so.
Done
--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com
From 0c9235f77fa9c75b1957810aa88a2572ed4ac1dc Mon Sep 17 00:00:00 2001
From: Dilip Kumar <dilipkumar@localhost.localdomain>
Date: Sun, 23 May 2021 21:27:58 +0530
Subject: [PATCH v2] Test for new standby not following promoted standby
---
src/test/recovery/t/025_timeline_issue.pl | 84 +++++++++++++++++++++++++++++++
src/test/recovery/t/cp_history_files | 8 +++
2 files changed, 92 insertions(+)
create mode 100644 src/test/recovery/t/025_timeline_issue.pl
create mode 100755 src/test/recovery/t/cp_history_files
diff --git a/src/test/recovery/t/025_timeline_issue.pl b/src/test/recovery/t/025_timeline_issue.pl
new file mode 100644
index 0000000..9031354
--- /dev/null
+++ b/src/test/recovery/t/025_timeline_issue.pl
@@ -0,0 +1,84 @@
+
+# Copyright (c) 2021, PostgreSQL Global Development Group
+
+# Testing streaming replication where standby is promoted and a new cascade
+# standby (without WAL) is connected to the promoted standby. Both archiving
+# and streaming are enabled but it should only get the history files from the
+# archive but not the WAL files so that it has to get the checkpoint record
+# from the promoted standby through streaming. Test that the cascade standby
+# should be able to follow the new primary (promoted standby).
+use strict;
+use warnings;
+use PostgresNode;
+use TestLib;
+use FindBin;
+use Test::More tests => 1;
+
+# Initialize primary node
+my $node_primary = get_new_node('primary');
+
+# Set archive command using 'cp_history_files' (custom command). The command
+# will only copy the history file and ignore all other WAL files. This is
+# required to reproduce the scenario where history files reach the archive
+# but not the WAL files when standby try to restore it from the archive so that
+# it needs to stream the checkpoint record from the primary.
+$node_primary->init(allows_streaming => 1, has_archiving => 1);
+my $archivedir_primary = $node_primary->archive_dir;
+$node_primary->append_conf(
+ 'postgresql.conf', qq(
+archive_command = '"$FindBin::RealBin/cp_history_files" "%p" "$archivedir_primary/%f"'
+));
+$node_primary->start;
+
+my $backup_name = 'my_backup';
+
+# Take backup from primary
+$node_primary->backup($backup_name);
+
+# Create streaming standby linking to primary
+my $node_standby = get_new_node('standby');
+$node_standby->init_from_backup($node_primary, $backup_name,
+ allows_streaming => 1, has_streaming => 1, has_archiving => 1);
+$node_standby->start;
+
+# Take backup of standby, use -Xnone so that pg_wal is empty.
+$node_standby->backup($backup_name, backup_options => ['-Xnone']);
+
+# Create cascading standby but don't start it yet.
+# Must set up both streaming and archiving.
+my $node_cascade = get_new_node('cascade');
+$node_cascade->init_from_backup($node_standby, $backup_name,
+ has_streaming => 1);
+
+# Setup restore command
+my $copy_command =
+ $TestLib::windows_os ? 'copy' : 'cp';
+
+$node_cascade->append_conf(
+ 'postgresql.conf', qq(
+restore_command = '$copy_command "$archivedir_primary/%f" "%p"'
+));
+
+# Promote the standby.
+$node_standby->psql('postgres', 'SELECT pg_promote()');
+
+# Start cascade node
+$node_cascade->start;
+
+# Create some content on promoted standby and check its presence in cascade standby
+$node_standby->safe_psql('postgres', "CREATE TABLE tab_int AS SELECT 1 AS a");
+
+# Wait for standbys to catch up
+$node_standby->wait_for_catchup($node_cascade, 'replay',
+ $node_standby->lsn('replay'));
+
+# Check cascade standby is able to follow the new primary
+my $result =
+ $node_cascade->safe_psql('postgres', "SELECT count(*) FROM tab_int");
+print "cascade: $result\n";
+is($result, qq(1), 'check streamed content on cascade standby');
+
+# clean up
+$node_primary->teardown_node;
+$node_standby->teardown_node;
+$node_cascade->teardown_node;
diff --git a/src/test/recovery/t/cp_history_files b/src/test/recovery/t/cp_history_files
new file mode 100755
index 0000000..8dfe019
--- /dev/null
+++ b/src/test/recovery/t/cp_history_files
@@ -0,0 +1,8 @@
+#!/usr/bin/perl
+
+use File::Copy;
+
+die "wrong number of arguments" if @ARGV != 2;
+my ($source, $target) = @ARGV;
+return if $source !~ /history/;
+copy($source, $target) or die "couldn't copy $source to $target: $!";
--
1.8.3.1
