Horton

Re: Race condition in recovery?

Andrew Dunstan <andrew@dunslane.net>

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From: Andrew Dunstan <andrew@dunslane.net>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Michael Paquier <michael@paquier.xyz>, Dilip Kumar <dilipbalaut@gmail.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-06-14T19:46:57Z
Lists: pgsql-hackers 
On 6/14/21 3:32 PM, Andrew Dunstan wrote:
> On 6/14/21 1:50 PM, Andrew Dunstan wrote:
>> On 6/14/21 1:11 PM, Robert Haas wrote:
>>> On Mon, Jun 14, 2021 at 12:56 PM Andrew Dunstan <andrew@dunslane.net> wrote:
>>>> $^X is not at all broken.
>>>>
>>>> The explanation here is pretty simple - the argument to perl2host is
>>>> meant to be a directory. If we're going to accomodate plain files then
>>>> we have some more work to do in TestLib.
>>> This explanation seems to contradict the documentation in TestLib.pm,
>>> which makes no mention of any such restriction.
>> Heres a snippet:
>>
>>
>>     sub perl2host
>>     {
>>         my ($subject) = @_;
>>         ...
>>         if (chdir $subject)
>>      
>>
>> Last time I looked you can't chdir to anything except a directory.
>
>
> Actually, I take it back, it does work for a file. I'll change it. I
> probably did this when something else wasn't working.




So, will you feel happier with this applied? I haven't tested it yet but
I'm confident it will work.


diff --git a/src/test/recovery/t/025_stuck_on_old_timeline.pl b/src/test/recovery/t/025_stuck_on_old_timeline.pl
index e4e58cb8ab..3e19bc4c50 100644
--- a/src/test/recovery/t/025_stuck_on_old_timeline.pl
+++ b/src/test/recovery/t/025_stuck_on_old_timeline.pl
@@ -24,11 +24,11 @@ my $node_primary = get_new_node('primary');
 # the timeline history file reaches the archive but before any of the WAL files
 # get there.
 $node_primary->init(allows_streaming => 1, has_archiving => 1);
-my $perlbin = $^X;
-if ($^O eq 'msys')
-{
-   $perlbin = TestLib::perl2host(dirname($^X)) . '\\' . basename($^X);
-}
+
+# Note: consistent use of forward slashes here avoids any escaping problems
+# that arise from use of backslashes. That means we need to double-quote all
+# the paths in the archive_command
+my $perlbin = TestLib::perl2host(^X);
 $perlbin =~ s!\\!/!g if $TestLib::windows_os;
 my $archivedir_primary = $node_primary->archive_dir;
 $archivedir_primary =~ s!\\!/!g if $TestLib::windows_os;
@@ -36,6 +36,8 @@ $node_primary->append_conf('postgresql.conf', qq(
 archive_command = '"$perlbin" "$FindBin::RealBin/cp_history_files" "%p" "$archivedir_primary/%f"'
 wal_keep_size=128MB
 ));
+# make sure that Msys perl doesn't complain about difficulty in setting locale
+# when called this way.
 local $ENV{PERL_BADLANG}=0;
 $node_primary->start;
 


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Commits

  1. Further refinement of stuck_on_old_timeline recovery test

  2. Adjust new test case to set wal_keep_segments.

  3. Adjust new test case to set wal_keep_size.

  4. Fix corner case failure of new standby to follow new primary.

  5. Back-port a few PostgresNode.pm methods.

  6. Allow PostgresNode.pm's backup method to accept backup_options.

  7. Add end-to-end testing of pg_basebackup's tar-format output.

  8. Allow PostgresNode.pm tests to wait for catchup

  9. Delay reading timeline history file until it's fetched from master.