From 18115d392fda06bf90635caaca5801d2ecffdefb Mon Sep 17 00:00:00 2001
From: ParadoxV5 <paradox.ver5@gmail.com>
Date: Thu, 27 Mar 2025 18:27:44 -0600
Subject: [PATCH] MDEV-35304 fixup: Timing-independent MTR test

Improve the `multi_source.connects_tried` feature test:
* Replace the main course from
  *checking `Connect_Tried` after sleeping a specific time* to
  *checking the duration after reaching a minimum `Connect_Tried`*
  * Not using a specific SLEEP eliminates the possibility (of failure)
    that it awakens before the `Connects_Tried` counter increments.
* In replacement-based tests of conventional views (SHOW & variants),
  assert the parallel values without distinguishing which is which
  * There were rare cases where both values end up equal (even though
    one was configured to tick more frequently than the other).
* Comment touchups

Reviewed-by: Kristian Nielsen <knielsen@knielsen-hq.org>
---
 .../suite/multi_source/connects_tried.result  | 39 ++++++++------
 .../suite/multi_source/connects_tried.test    | 53 ++++++++++++-------
 2 files changed, 57 insertions(+), 35 deletions(-)

diff --git a/mysql-test/suite/multi_source/connects_tried.result b/mysql-test/suite/multi_source/connects_tried.result
index beb08754338..cf2069a864f 100644
--- a/mysql-test/suite/multi_source/connects_tried.result
+++ b/mysql-test/suite/multi_source/connects_tried.result
@@ -3,35 +3,40 @@ include/master-slave.inc [rpl_server_count=3]
 include/rpl_stop_server.inc [server_number=1]
 include/rpl_stop_server.inc [server_number=3]
 connection slave;
-CHANGE MASTER TO master_connect_retry=1;
-CHANGE MASTER 'named' TO master_host='127.0.0.1', master_port=SERVER_MYPORT_3, master_user='root', master_ssl_verify_server_cert=0, master_connect_retry=2;
+CHANGE MASTER TO master_connect_retry=2;
+CHANGE MASTER 'named' TO master_host='127.0.0.1', master_port=SERVER_MYPORT_3, master_user='root', master_ssl_verify_server_cert=0, master_connect_retry=1;
 # `Connects_Tried` is 0 before connections begin.
 SELECT Connection_name, Connects_Tried FROM information_schema.SLAVE_STATUS;
 Connection_name	Connects_Tried
 	0
 named	0
 START ALL SLAVES;
+SET @time_begin= CURRENT_TIMESTAMP(1);
 SET @@SESSION.default_master_connection= 'named';
 include/wait_for_slave_io_error.inc [errno=2003]
 SET @@SESSION.default_master_connection= '';
 include/wait_for_slave_io_error.inc [errno=2003]
 CREATE TEMPORARY TABLE status_begin AS
 SELECT Connection_name, Connects_Tried FROM information_schema.SLAVE_STATUS;
-# `Connects_Tried` is 1 immediately after connections begin.
+# `Connects_Tried` is 1 immediately after connection begins.
 SELECT Connection_name, Connects_Tried
 FROM status_begin
 WHERE Connects_Tried <= 0;
 Connection_name	Connects_Tried
-DO SLEEP(3);
-# `Connects_Tried` increments (at least) 3 for connection '' and 1 for 'named'.
-CREATE TEMPORARY TABLE status_sleep AS
-SELECT Connection_name, Connects_Tried FROM information_schema.SLAVE_STATUS;
-SELECT *
-FROM status_begin JOIN status_sleep USING(Connection_name)
-WHERE status_sleep.Connects_Tried - status_begin.Connects_Tried <
-IF(LENGTH(Connection_name), 1, 3);
-Connection_name	Connects_Tried	Connects_Tried
-# Boot replication up and assert final count
+# `Connects_Tried` takes (at least) 2s to increment for connection '' and 1s for 'named'.
+SET @@SESSION.default_master_connection= 'named';
+include/wait_for_slave_param.inc [Connects_Tried]
+SELECT @time_begin, CURRENT_TIMESTAMP(1)
+WHERE TIMESTAMPDIFF(SECOND, @time_begin, CURRENT_TIMESTAMP(1)) < 1;
+@time_begin	CURRENT_TIMESTAMP(1)
+CREATE TEMPORARY TABLE status_sleep AS SELECT 'named' Connection_name, Connects_Tried Connects_Tried;
+SET @@SESSION.default_master_connection= '';
+include/wait_for_slave_param.inc [Connects_Tried]
+SELECT @time_begin, CURRENT_TIMESTAMP(1)
+WHERE TIMESTAMPDIFF(SECOND, @time_begin, CURRENT_TIMESTAMP(1)) < 2;
+@time_begin	CURRENT_TIMESTAMP(1)
+INSERT INTO status_sleep SET Connection_name= '', Connects_Tried= Connects_Tried;
+# Boot replication up and compare the final counts
 include/rpl_start_server.inc [server_number=1]
 include/rpl_start_server.inc [server_number=3]
 connection slave;
@@ -58,11 +63,11 @@ Connection_name	Connects_Tried	Connects_Tried
 SELECT * FROM status_end;
 Connection_name	Connects_Tried
 	connects_tried
-named	connects_tried_named
+named	connects_tried
 SELECT * FROM status_end;
 Connection_name	Connects_Tried
 	connects_tried
-named	connects_tried_named
+named	connects_tried
 STOP ALL SLAVES;
 SET @@SESSION.default_master_connection= 'named';
 include/wait_for_slave_to_stop.inc
@@ -83,7 +88,7 @@ SELECT Connection_name, Connects_Tried FROM information_schema.SLAVE_STATUS;
 SELECT *
 FROM status_restart JOIN status_stop USING(Connection_name)
 WHERE status_restart.Connects_Tried NOT BETWEEN IF(
-LENGTH(Connection_name), status_stop.Connects_Tried, 1
+Connection_name = '', 1, status_stop.Connects_Tried
 ) AND status_stop.Connects_Tried;
 Connection_name	Connects_Tried	Connects_Tried
 STOP SLAVE;
@@ -95,7 +100,7 @@ SELECT Connection_name, Connects_Tried FROM information_schema.SLAVE_STATUS;
 SELECT *
 FROM status_reset JOIN status_restart USING(Connection_name)
 WHERE status_reset.Connects_Tried <>
-IF(LENGTH(Connection_name), status_restart.Connects_Tried, 0);
+IF(Connection_name = '', 0, status_restart.Connects_Tried);
 Connection_name	Connects_Tried	Connects_Tried
 # Cleanup
 RESET SLAVE 'named' ALL;
diff --git a/mysql-test/suite/multi_source/connects_tried.test b/mysql-test/suite/multi_source/connects_tried.test
index dd4a70552fd..27f47966979 100644
--- a/mysql-test/suite/multi_source/connects_tried.test
+++ b/mysql-test/suite/multi_source/connects_tried.test
@@ -4,7 +4,7 @@
 # separate counters in parallel multi-source (SHOW SLAVE [name] STATUS).
 #
 # Note: nearly all SELECT results are timing-sensitive,
-# they therefore list unexpected rows because.
+# therefore, they only list unexpected rows.
 
 --source include/have_binlog_format_mixed.inc # The test is agnostic of binlog formats.
 # `rpl_*.inc` (still) expects `server_1` be `master` and `server_2` be `slave`.
@@ -17,14 +17,16 @@
 --source include/rpl_stop_server.inc
 
 --connection slave
-CHANGE MASTER TO master_connect_retry=1;
+CHANGE MASTER TO master_connect_retry=2;
 --replace_result $SERVER_MYPORT_3 SERVER_MYPORT_3
---eval CHANGE MASTER 'named' TO master_host='127.0.0.1', master_port=$SERVER_MYPORT_3, master_user='root', master_ssl_verify_server_cert=0, master_connect_retry=2
+--eval CHANGE MASTER 'named' TO master_host='127.0.0.1', master_port=$SERVER_MYPORT_3, master_user='root', master_ssl_verify_server_cert=0, master_connect_retry=1
 --echo # `Connects_Tried` is 0 before connections begin.
 SELECT Connection_name, Connects_Tried FROM information_schema.SLAVE_STATUS;
 
 --disable_warnings
 START ALL SLAVES; # will fail because the masters are down
+SET @time_begin= CURRENT_TIMESTAMP(1);
+--enable_warnings
 # CR_CONN_HOST_ERROR
 --let $slave_io_errno= 2003
 --let $slave_io_error_is_nonfatal= 1
@@ -33,25 +35,39 @@ SET @@SESSION.default_master_connection= 'named';
 --let $slave_io_error_is_nonfatal= 1
 SET @@SESSION.default_master_connection= '';
 --source include/wait_for_slave_io_error.inc
---enable_warnings
 
 CREATE TEMPORARY TABLE status_begin AS
   SELECT Connection_name, Connects_Tried FROM information_schema.SLAVE_STATUS;
---echo # `Connects_Tried` is 1 immediately after connections begin.
+--echo # `Connects_Tried` is 1 immediately after connection begins.
+# (Though it might have ticked additional reconnects by now if stress-testing.)
 SELECT Connection_name, Connects_Tried
   FROM status_begin
   WHERE Connects_Tried <= 0;
 
-DO SLEEP(3);
---echo # `Connects_Tried` increments (at least) 3 for connection '' and 1 for 'named'.
-CREATE TEMPORARY TABLE status_sleep AS
-  SELECT Connection_name, Connects_Tried FROM information_schema.SLAVE_STATUS;
-SELECT *
-  FROM status_begin JOIN status_sleep USING(Connection_name)
-  WHERE status_sleep.Connects_Tried - status_begin.Connects_Tried <
-    IF(LENGTH(Connection_name), 1, 3);
+--echo # `Connects_Tried` takes (at least) 2s to increment for connection '' and 1s for 'named'.
+--let $slave_param= Connects_Tried
+--let $slave_param_comparison= >
 
---echo # Boot replication up and assert final count
+SET @@SESSION.default_master_connection= 'named';
+--let $slave_param_value= `SELECT Connects_Tried FROM status_begin WHERE Connection_name = ''`
+--source include/wait_for_slave_param.inc
+SELECT @time_begin, CURRENT_TIMESTAMP(1)
+  WHERE TIMESTAMPDIFF(SECOND, @time_begin, CURRENT_TIMESTAMP(1)) < 1;
+--replace_result $_show_slave_status_value Connects_Tried
+--eval CREATE TEMPORARY TABLE status_sleep AS SELECT 'named' Connection_name, $_show_slave_status_value Connects_Tried
+
+SET @@SESSION.default_master_connection= '';
+--let $slave_param_value= `SELECT Connects_Tried FROM status_begin WHERE Connection_name <> ''`
+--source include/wait_for_slave_param.inc
+SELECT @time_begin, CURRENT_TIMESTAMP(1)
+  WHERE TIMESTAMPDIFF(SECOND, @time_begin, CURRENT_TIMESTAMP(1)) < 2;
+--replace_result $_show_slave_status_value Connects_Tried
+--eval INSERT INTO status_sleep SET Connection_name= '', Connects_Tried= $_show_slave_status_value
+
+--echo # Boot replication up and compare the final counts
+# (In an ideal environment, the 'named' connection that reconnects
+#  more frequently would have a `Connects_Tried` ahead of the '' one.
+#  In stress-testing, it instead depends on the thread timing and scheduling.)
 --let $rpl_server_number= 1
 --source include/rpl_start_server.inc
 --let $rpl_server_number= 3
@@ -60,6 +76,7 @@ SELECT *
 # `wait_for_slave_io_to_start.inc` fails if the IO thread has an error.
 --let $slave_param= Slave_IO_Running
 --let $slave_param_value= Yes
+--let $slave_param_comparison= =
 SET @@SESSION.default_master_connection= 'named';
 --source include/wait_for_slave_param.inc
 SET @@SESSION.default_master_connection= '';
@@ -83,11 +100,11 @@ SELECT *
 --echo # Conventional views
 --let $connects_tried= query_get_value("SHOW SLAVE STATUS", Connects_Tried, 1)
 --let $connects_tried_named= query_get_value("SHOW SLAVE 'named' STATUS", Connects_Tried, 1)
---replace_result $connects_tried connects_tried $connects_tried_named connects_tried_named
+--replace_result $connects_tried connects_tried $connects_tried_named connects_tried
 SELECT * FROM status_end;
 --let $connects_tried= query_get_value("SHOW ALL SLAVES STATUS", Connects_Tried, 1)
 --let $connects_tried_named= query_get_value("SHOW ALL SLAVES STATUS", Connects_Tried, 2)
---replace_result $connects_tried connects_tried $connects_tried_named connects_tried_named
+--replace_result $connects_tried connects_tried $connects_tried_named connects_tried
 SELECT * FROM status_end;
 
 --disable_warnings
@@ -113,7 +130,7 @@ CREATE TEMPORARY TABLE status_restart AS
 SELECT *
   FROM status_restart JOIN status_stop USING(Connection_name)
   WHERE status_restart.Connects_Tried NOT BETWEEN IF(
-    LENGTH(Connection_name), status_stop.Connects_Tried, 1
+    Connection_name = '', 1, status_stop.Connects_Tried
   ) AND status_stop.Connects_Tried;
 
 STOP SLAVE;
@@ -125,7 +142,7 @@ CREATE TEMPORARY TABLE status_reset AS
 SELECT *
   FROM status_reset JOIN status_restart USING(Connection_name)
   WHERE status_reset.Connects_Tried <>
-    IF(LENGTH(Connection_name), status_restart.Connects_Tried, 0);
+    IF(Connection_name = '', 0, status_restart.Connects_Tried);
 
 --echo # Cleanup
 RESET SLAVE 'named' ALL;