postgres.git / summary / log / commit / refs

commit    f0b0b1ddb53a66e57404cd1bfa4aa2944c3e77c6
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Thu Jan 20 22:28:07 2022 +0000
First released in: 15.0, 10.20, 11.15, 12.10, 13.6, 14.2

    Tighten TAP tests' tracking of postmaster state some more.
    
    Commits 6c4a8903b et al. had a couple of deficiencies:
    
    * The logic I added to Cluster::start to see if a PID file is present
    could be fooled by a stale PID file left over from a previous
    postmaster.  To fix, if we're not sure whether we expect to find a
    running postmaster or not, validate the PID using "kill 0".
    
    * 017_shm.pl has a loop in which it just issues repeated Cluster::start
    calls; this will fail if some invocation fails but leaves self->_pid
    set.  Per buildfarm results, the above fix is not enough to make this
    safe: we might have "validated" a PID for a postmaster that exits
    immediately after we look.  Hence, match each failed start call with
    a stop call that will get us back to the self->_pid == undef state.
    Add a fail_ok option to Cluster::stop to make this work.
    
    Discussion: https://postgr.es/m/CA+hUKGKV6fOHvfiPt8=dOKzvswjAyLoFoJF1iQXMNpi7+hD1JQ@mail.gmail.com


 src/test/perl/PostgresNode.pm  | 40 ++++++++++++++++++++++++++++++++++------
 src/test/recovery/t/017_shm.pl |  3 +++
 2 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/src/test/perl/PostgresNode.pm b/src/test/perl/PostgresNode.pm
index a5720963539..cb8a6423f43 100644
--- a/src/test/perl/PostgresNode.pm
+++ b/src/test/perl/PostgresNode.pm
@@ -826,20 +826,37 @@ Note: if the node is already known stopped, this does nothing.
 However, if we think it's running and it's not, it's important for
 this to fail.  Otherwise, tests might fail to detect server crashes.
 
+With optional extra param fail_ok => 1, returns 0 for failure
+instead of bailing out.
+
 =cut
 
 sub stop
 {
-	my ($self, $mode) = @_;
-	my $port   = $self->port;
+	my ($self, $mode, %params) = @_;
 	my $pgdata = $self->data_dir;
 	my $name   = $self->name;
+	my $ret;
 	$mode = 'fast' unless defined $mode;
-	return unless defined $self->{_pid};
+	return 1 unless defined $self->{_pid};
+
 	print "### Stopping node \"$name\" using mode $mode\n";
-	TestLib::system_or_bail('pg_ctl', '-D', $pgdata, '-m', $mode, 'stop');
+	$ret = TestLib::system_log('pg_ctl', '-D', $pgdata,
+		'-m', $mode, 'stop');
+
+	if ($ret != 0)
+	{
+		print "# pg_ctl stop failed: $ret\n";
+
+		# Check to see if we still have a postmaster or not.
+		$self->_update_pid(-1);
+
+		BAIL_OUT("pg_ctl stop failed") unless $params{fail_ok};
+		return 0;
+	}
+
 	$self->_update_pid(0);
-	return;
+	return 1;
 }
 
 =pod
@@ -1038,9 +1055,20 @@ sub _update_pid
 	if (open my $pidfile, '<', $self->data_dir . "/postmaster.pid")
 	{
 		chomp($self->{_pid} = <$pidfile>);
-		print "# Postmaster PID for node \"$name\" is $self->{_pid}\n";
 		close $pidfile;
 
+		# If we aren't sure what to expect, validate the PID using kill().
+		# This protects against stale PID files left by crashed postmasters.
+		if ($is_running == -1 && kill(0, $self->{_pid}) == 0)
+		{
+			print
+			  "# Stale postmaster.pid file for node \"$name\": PID $self->{_pid} no longer exists\n";
+			$self->{_pid} = undef;
+			return;
+		}
+
+		print "# Postmaster PID for node \"$name\" is $self->{_pid}\n";
+
 		# If we found a pidfile when there shouldn't be one, complain.
 		BAIL_OUT("postmaster.pid unexpectedly present") if $is_running == 0;
 		return;
diff --git a/src/test/recovery/t/017_shm.pl b/src/test/recovery/t/017_shm.pl
index 70d6015fd40..01772186754 100644
--- a/src/test/recovery/t/017_shm.pl
+++ b/src/test/recovery/t/017_shm.pl
@@ -196,6 +196,9 @@ sub poll_start
 		# Wait 0.1 second before retrying.
 		usleep(100_000);
 
+		# Clean up in case the start attempt just timed out or some such.
+		$node->stop('fast', fail_ok => 1);
+
 		$attempts++;
 	}
 


[parent: 22d8c2570fea]