On Wed, Mar 9, 2016 at 12:14 AM, Alvaro Herrera
<alvhe...@2ndquadrant.com> wrote:
> Is there anything we can do to short-circuit the wait in the case that
> replication happens promptly?  A one-minute wait would be acceptable we
> terminate it early by checking every second.

After sleeping (best debugger ever) on that, actually a way popped up
in my mind, and I propose the attached, which refactors a bit 005 and
checks that the LSN position of master has been applied on standby
after at least the delay wanted. A maximum delay of 90s is authorized,
like poll_query_until.
diff --git a/src/test/recovery/t/005_replay_delay.pl b/src/test/recovery/t/005_replay_delay.pl
index 986851b..f95b5ab 100644
--- a/src/test/recovery/t/005_replay_delay.pl
+++ b/src/test/recovery/t/005_replay_delay.pl
@@ -3,7 +3,7 @@ use strict;
 use warnings;
 use PostgresNode;
 use TestLib;
-use Test::More tests => 2;
+use Test::More tests => 1;
 # Initialize master node
 my $node_master = get_new_node('master');
@@ -32,18 +32,30 @@ $node_standby->start;
 # depending on the delay of 2s applied above.
 	"INSERT INTO tab_int VALUES (generate_series(11,20))");
-sleep 1;
-# Here we should have only 10 rows
-my $result = $node_standby->safe_psql('postgres', "SELECT count(*) FROM tab_int");
-is($result, qq(10), 'check content with delay of 1s');
-# Now wait for replay to complete on standby
+# Now wait for replay to complete on standby. We check if the current
+# LSN of master has been applied after at least 2s.
 my $until_lsn =
   $node_master->safe_psql('postgres', "SELECT pg_current_xlog_location();");
-my $caughtup_query =
-  "SELECT '$until_lsn'::pg_lsn <= pg_last_xlog_replay_location()";
-$node_standby->poll_query_until('postgres', $caughtup_query)
-  or die "Timed out while waiting for standby to catch up";
-$result = $node_standby->safe_psql('postgres', "SELECT count(*) FROM tab_int");
-is($result, qq(20), 'check content with delay of 2s');
+my $max_attempts = 90;
+my $attempts     = 0;
+while ($attempts < $max_attempts)
+	my $replay_status =
+	  $node_standby->safe_psql('postgres',
+		"SELECT (pg_last_xlog_replay_location() - '$until_lsn'::pg_lsn) >= 0");
+	# Leave now if standby has replayed at least up to the point of
+	# master.
+	last if $replay_status eq 't';
+	sleep 1;
+	$attempts++;
+die "Maximum number of attempts reached" if $attempts >= $max_attempts;
+# This test is valid only if LSN has been applied with at least
+# the minimum apply delay expected.
+ok($attempts >= 2, 'Check if LSN is applied on standby after 2s');
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