MDEV-28461 semisync-slave server recovery fails to rollback prepared …

…transaction

that is not in binlog.

Post-crash recovery of --rpl-semi-sync-slave-enabled server
failed to recognize a transaction in-doubt that needed rolled back.
A prepared-but-not-in-binlog transaction gets committed instead
to possibly create inconsistency with a master (e.g the way it was observed
in the bug report).

The semisync recovery is corrected now with initializing binlog coordinates
of any transaction in-doubt to the maximum offset which is
unreachable.
In effect when a prepared transaction that is not found in binlog
it will be decided to rollback because it's guaranteed to reside
in a truncated tail area of binlog.

Mtr tests are reinforced to cover the described scenario.

mysql-test/suite/binlog/r/binlog_truncate_active_log.result

@@ -4,11 +4,13 @@ RESET MASTER;
 SET @@global.sync_binlog=1;
 CREATE TABLE t (f INT) ENGINE=INNODB;
 CREATE TABLE t2 (f INT) ENGINE=INNODB;
+CREATE TABLE t4 (f INT) ENGINE=INNODB;
 CREATE TABLE tm (f INT) ENGINE=Aria;
 # Case A.
 connect master1,localhost,root,,;
 connect master2,localhost,root,,;
 connect master3,localhost,root,,;
+connect master4,localhost,root,,;
 connection default;
 INSERT INTO t  VALUES (10);
 INSERT INTO tm VALUES (10);
@@ -23,14 +25,23 @@ connection master3;
 SET DEBUG_SYNC= "now WAIT_FOR master2_ready";
 SELECT @@global.gtid_binlog_pos as 'Before the crash';
 Before the crash
-0-1-7
+0-1-8
+connection master4;
+SET DEBUG_SYNC= "ha_commit_trans_before_log_and_order SIGNAL master4_ready WAIT_FOR signal_never_arrives";
+INSERT INTO t4  VALUES (13);
+connection master3;
+SET DEBUG_SYNC= "now WAIT_FOR master4_ready";
+SELECT @@global.gtid_binlog_pos as 'Before the crash and never logged trx';
+Before the crash and never logged trx
+0-1-8
 connection default;
 # Kill the server
 disconnect master1;
 disconnect master2;
 disconnect master3;
-# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1
-FOUND 1 /Successfully truncated.*to remove transactions starting from GTID 0-1-6/ in mysqld.1.err
+disconnect master4;
+# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1 --log-warnings=3
+FOUND 1 /Successfully truncated.*to remove transactions starting from GTID 0-1-7/ in mysqld.1.err
 Pre-crash binlog file content:
 include/show_binlog_events.inc
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
@@ -39,6 +50,8 @@ master-bin.000001	#	Query	#	#	use `test`; CREATE TABLE t (f INT) ENGINE=INNODB
 master-bin.000001	#	Gtid	#	#	GTID #-#-#
 master-bin.000001	#	Query	#	#	use `test`; CREATE TABLE t2 (f INT) ENGINE=INNODB
 master-bin.000001	#	Gtid	#	#	GTID #-#-#
+master-bin.000001	#	Query	#	#	use `test`; CREATE TABLE t4 (f INT) ENGINE=INNODB
+master-bin.000001	#	Gtid	#	#	GTID #-#-#
 master-bin.000001	#	Query	#	#	use `test`; CREATE TABLE tm (f INT) ENGINE=Aria
 master-bin.000001	#	Gtid	#	#	BEGIN GTID #-#-#
 master-bin.000001	#	Query	#	#	use `test`; INSERT INTO t  VALUES (10)
@@ -48,16 +61,20 @@ master-bin.000001	#	Query	#	#	use `test`; INSERT INTO tm VALUES (10)
 master-bin.000001	#	Query	#	#	COMMIT
 SELECT @@global.gtid_binlog_pos as 'After the crash';
 After the crash
-0-1-5
+0-1-6
 "One row should be present in table 't'"
 SELECT * FROM t;
 f
 10
+"No row should be present in table 't4'"
+SELECT * FROM t4;
+f
 DELETE FROM t;
 # Case B.
 connect master1,localhost,root,,;
 connect master2,localhost,root,,;
 connect master3,localhost,root,,;
+connect master4,localhost,root,,;
 connection default;
 INSERT INTO t  VALUES (10);
 INSERT INTO tm VALUES (10);
@@ -72,14 +89,23 @@ connection master3;
 SET DEBUG_SYNC= "now WAIT_FOR master2_ready";
 SELECT @@global.gtid_binlog_pos as 'Before the crash';
 Before the crash
-0-1-10
+0-1-11
+connection master4;
+SET DEBUG_SYNC= "ha_commit_trans_before_log_and_order SIGNAL master4_ready WAIT_FOR signal_never_arrives";
+INSERT INTO t4  VALUES (13);
+connection master3;
+SET DEBUG_SYNC= "now WAIT_FOR master4_ready";
+SELECT @@global.gtid_binlog_pos as 'Before the crash and never logged trx';
+Before the crash and never logged trx
+0-1-11
 connection default;
 # Kill the server
 disconnect master1;
 disconnect master2;
 disconnect master3;
-# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1
-FOUND 1 /Successfully truncated.*to remove transactions starting from GTID 0-1-10/ in mysqld.1.err
+disconnect master4;
+# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1 --log-warnings=3
+FOUND 1 /Successfully truncated.*to remove transactions starting from GTID 0-1-11/ in mysqld.1.err
 Pre-crash binlog file content:
 include/show_binlog_events.inc
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
@@ -97,11 +123,14 @@ master-bin.000002	#	Query	#	#	use `test`; DELETE FROM t2 WHERE f = 0
 master-bin.000002	#	Query	#	#	COMMIT
 SELECT @@global.gtid_binlog_pos as 'After the crash';
 After the crash
-0-1-9
+0-1-10
 "One row should be present in table 't'"
 SELECT * FROM t;
 f
 10
+"No row should be present in table 't4'"
+SELECT * FROM t4;
+f
 DELETE FROM t;
 # Case C.
 CREATE PROCEDURE sp_blank_xa()
@@ -114,6 +143,7 @@ END|
 connect master1,localhost,root,,;
 connect master2,localhost,root,,;
 connect master3,localhost,root,,;
+connect master4,localhost,root,,;
 connection default;
 INSERT INTO t  VALUES (10);
 INSERT INTO tm VALUES (10);
@@ -128,14 +158,23 @@ connection master3;
 SET DEBUG_SYNC= "now WAIT_FOR master2_ready";
 SELECT @@global.gtid_binlog_pos as 'Before the crash';
 Before the crash
-0-1-15
+0-1-16
+connection master4;
+SET DEBUG_SYNC= "ha_commit_trans_before_log_and_order SIGNAL master4_ready WAIT_FOR signal_never_arrives";
+INSERT INTO t4  VALUES (13);
+connection master3;
+SET DEBUG_SYNC= "now WAIT_FOR master4_ready";
+SELECT @@global.gtid_binlog_pos as 'Before the crash and never logged trx';
+Before the crash and never logged trx
+0-1-16
 connection default;
 # Kill the server
 disconnect master1;
 disconnect master2;
 disconnect master3;
-# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1
-FOUND 1 /Successfully truncated.*to remove transactions starting from GTID 0-1-14/ in mysqld.1.err
+disconnect master4;
+# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1 --log-warnings=3
+FOUND 1 /Successfully truncated.*to remove transactions starting from GTID 0-1-15/ in mysqld.1.err
 Pre-crash binlog file content:
 include/show_binlog_events.inc
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
@@ -158,11 +197,14 @@ master-bin.000003	#	Query	#	#	use `test`; INSERT INTO tm VALUES (10)
 master-bin.000003	#	Query	#	#	COMMIT
 SELECT @@global.gtid_binlog_pos as 'After the crash';
 After the crash
-0-1-13
+0-1-14
 "One row should be present in table 't'"
 SELECT * FROM t;
 f
 10
+"No row should be present in table 't4'"
+SELECT * FROM t4;
+f
 DELETE FROM t;
 DROP PROCEDURE sp_blank_xa;
 # Case D.
@@ -176,6 +218,7 @@ END|
 connect master1,localhost,root,,;
 connect master2,localhost,root,,;
 connect master3,localhost,root,,;
+connect master4,localhost,root,,;
 connection default;
 INSERT INTO t  VALUES (10);
 INSERT INTO tm VALUES (10);
@@ -190,14 +233,23 @@ connection master3;
 SET DEBUG_SYNC= "now WAIT_FOR master2_ready";
 SELECT @@global.gtid_binlog_pos as 'Before the crash';
 Before the crash
-0-1-20
+0-1-21
+connection master4;
+SET DEBUG_SYNC= "ha_commit_trans_before_log_and_order SIGNAL master4_ready WAIT_FOR signal_never_arrives";
+INSERT INTO t4  VALUES (13);
+connection master3;
+SET DEBUG_SYNC= "now WAIT_FOR master4_ready";
+SELECT @@global.gtid_binlog_pos as 'Before the crash and never logged trx';
+Before the crash and never logged trx
+0-1-21
 connection default;
 # Kill the server
 disconnect master1;
 disconnect master2;
 disconnect master3;
-# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1
-FOUND 1 /Successfully truncated.*to remove transactions starting from GTID 0-1-20/ in mysqld.1.err
+disconnect master4;
+# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1 --log-warnings=3
+FOUND 1 /Successfully truncated.*to remove transactions starting from GTID 0-1-21/ in mysqld.1.err
 Pre-crash binlog file content:
 include/show_binlog_events.inc
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
@@ -226,11 +278,14 @@ master-bin.000004	#	Query	#	#	XA END X'786964',X'',1
 master-bin.000004	#	XA_prepare	#	#	XA PREPARE X'786964',X'',1
 SELECT @@global.gtid_binlog_pos as 'After the crash';
 After the crash
-0-1-19
+0-1-20
 "One row should be present in table 't'"
 SELECT * FROM t;
 f
 10
+"No row should be present in table 't4'"
+SELECT * FROM t4;
+f
 DELETE FROM t;
 DROP PROCEDURE sp_xa;
 # Cleanup

mysql-test/suite/binlog/r/binlog_truncate_multi_log.result

@@ -22,6 +22,11 @@ SET DEBUG_SYNC= "commit_before_get_LOCK_commit_ordered SIGNAL master2_ready WAIT
 INSERT INTO ti VALUES (3, "not gonna survive");
 connection default;
 SET DEBUG_SYNC= "now WAIT_FOR master2_ready";
+connect master3,localhost,root,,;
+SET DEBUG_SYNC= "ha_commit_trans_before_log_and_order SIGNAL master3_ready WAIT_FOR master3_go_never_arrives";
+INSERT INTO ti VALUES (4, "not gonna be log therefore survive"),(5, "ditto");
+connection default;
+SET DEBUG_SYNC= "now WAIT_FOR master3_ready";
 "List of binary logs before crash"
 show binary logs;
 Log_name	File_size
@@ -36,7 +41,8 @@ connection default;
 # Kill the server
 disconnect master1;
 disconnect master2;
-# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1
+disconnect master3;
+# restart: --rpl-semi-sync-slave-enabled=1 --sync-binlog=1 --log-warnings=3
 FOUND 1 /truncated binlog file:.*master.*000002/ in mysqld.1.err
 "One record should be present in table"
 SELECT * FROM ti;

mysql-test/suite/binlog/t/binlog_truncate_active_log.inc

@@ -1,6 +1,7 @@
 connect(master1,localhost,root,,);
 connect(master2,localhost,root,,);
 connect(master3,localhost,root,,);
+connect(master4,localhost,root,,);
 
 --connection default
 
@@ -22,16 +23,26 @@ SET DEBUG_SYNC= "commit_before_get_LOCK_after_binlog_sync SIGNAL master2_ready";
 SET DEBUG_SYNC= "now WAIT_FOR master2_ready";
 SELECT @@global.gtid_binlog_pos as 'Before the crash';
 
+--connection master4
+# Simulate prepared & not-logged trx; it will never recover.
+SET DEBUG_SYNC= "ha_commit_trans_before_log_and_order SIGNAL master4_ready WAIT_FOR signal_never_arrives";
+--send INSERT INTO t4  VALUES (13)
+
+--connection master3
+SET DEBUG_SYNC= "now WAIT_FOR master4_ready";
+SELECT @@global.gtid_binlog_pos as 'Before the crash and never logged trx';
+
 --connection default
 --source include/kill_mysqld.inc
 --disconnect master1
 --disconnect master2
 --disconnect master3
+--disconnect master4
 
 #
 # Server restart
 #
---let $restart_parameters= --rpl-semi-sync-slave-enabled=1 --sync-binlog=1
+--let $restart_parameters= --rpl-semi-sync-slave-enabled=1 --sync-binlog=1 --log-warnings=3
 --source include/start_mysqld.inc
 
 # Check error log for a successful truncate message.
@@ -49,6 +60,8 @@ SELECT @@global.gtid_binlog_pos as 'Before the crash';
 SELECT @@global.gtid_binlog_pos as 'After the crash';
 --echo "One row should be present in table 't'"
 SELECT * FROM t;
+--echo "No row should be present in table 't4'"
+SELECT * FROM t4;
 
 # prepare binlog file index for the next test
 --inc $binlog_file_index

mysql-test/suite/binlog/t/binlog_truncate_active_log.test

@@ -25,6 +25,7 @@ RESET MASTER;
 SET @@global.sync_binlog=1;
 CREATE TABLE t (f INT) ENGINE=INNODB;
 CREATE TABLE t2 (f INT) ENGINE=INNODB;
+CREATE TABLE t4 (f INT) ENGINE=INNODB;
 CREATE TABLE tm (f INT) ENGINE=Aria;
 
 # Old (pre-crash) binlog file index initial value.
@@ -42,14 +43,14 @@ CREATE TABLE tm (f INT) ENGINE=Aria;
 # 'query1' onwards will be removed from the binary log.
 # Show-binlog-events is to prove that.
 
---let $truncate_gtid_pos = 0-1-6
+--let $truncate_gtid_pos = 0-1-7
 --let $query1 = INSERT INTO t VALUES (20)
 --let $query2 = DELETE FROM t2 WHERE f = 0 /* no such record */
 --source binlog_truncate_active_log.inc
 
 --echo # Case B.
 # The inverted sequence ends up to truncate starting from $query2
---let $truncate_gtid_pos = 0-1-10
+--let $truncate_gtid_pos = 0-1-11
 --let $query1 = DELETE FROM t2 WHERE f = 0
 --let $query2 = INSERT INTO t VALUES (20)
 --source binlog_truncate_active_log.inc
@@ -68,7 +69,7 @@ delimiter ;|
 
 # The same as in A with $query2 being the zero-engine XA transaction.
 # Both $query1 and $query2 are going to be truncated.
---let $truncate_gtid_pos = 0-1-14
+--let $truncate_gtid_pos = 0-1-15
 --let $query1 = INSERT INTO t VALUES (20)
 --let $query2 = CALL sp_blank_xa
 --source binlog_truncate_active_log.inc
@@ -89,7 +90,7 @@ delimiter ;|
 
 # The same as in B with $query1 being the prepared XA transaction.
 # Truncation must occurs at $query2.
---let $truncate_gtid_pos = 0-1-20
+--let $truncate_gtid_pos = 0-1-21
 --let $query1 = CALL sp_xa
 --let $query2 = INSERT INTO t2 VALUES (20)
 --source binlog_truncate_active_log.inc

mysql-test/suite/binlog/t/binlog_truncate_multi_log.test

@@ -40,6 +40,15 @@ SET DEBUG_SYNC= "commit_before_get_LOCK_commit_ordered SIGNAL master2_ready WAIT
 
 --connection default
 SET DEBUG_SYNC= "now WAIT_FOR master2_ready";
+
+connect(master3,localhost,root,,);
+# The 3nd trx for recovery, it won't get into binlog nor therefore recover
+SET DEBUG_SYNC= "ha_commit_trans_before_log_and_order SIGNAL master3_ready WAIT_FOR master3_go_never_arrives";
+--send INSERT INTO ti VALUES (4, "not gonna be log therefore survive"),(5, "ditto")
+
+--connection default
+SET DEBUG_SYNC= "now WAIT_FOR master3_ready";
+
 --echo "List of binary logs before crash"
 --source include/show_binary_logs.inc
 --echo # The gtid binlog state prior the crash will be truncated at the end of the test
@@ -49,11 +58,12 @@ SELECT @@global.gtid_binlog_state;
 --source include/kill_mysqld.inc
 --disconnect master1
 --disconnect master2
+--disconnect master3
 
 #
 # Server restart
 #
---let $restart_parameters= --rpl-semi-sync-slave-enabled=1 --sync-binlog=1
+--let $restart_parameters= --rpl-semi-sync-slave-enabled=1 --sync-binlog=1 --log-warnings=3
 --source include/start_mysqld.inc
 
 # Check error log for a successful truncate message.

sql/handler.h

@@ -963,6 +963,7 @@ typedef struct xid_t XID;
 */
 typedef uint Binlog_file_id;
 const Binlog_file_id MAX_binlog_id= UINT_MAX;
+const my_off_t       MAX_off_t    = (~(my_off_t) 0);
 /*
   Compound binlog-id and byte offset of transaction's first event
   in a sequence (e.g the recovery sequence) of binlog files.
@@ -977,14 +978,22 @@ struct xid_recovery_member
   my_xid xid;
   uint in_engine_prepare;  // number of engines that have xid prepared
   bool decided_to_commit;
-  Binlog_offset binlog_coord; // semisync recovery binlog offset
+  /*
+    Semisync recovery binlog offset. It's initialized with the maximum
+    unreachable offset. The max value will remain for any transaction
+    not found in binlog to yield its rollback decision as it's guaranteed
+    to be within a truncated tail part of the binlog.
+  */
+  Binlog_offset binlog_coord;
   XID *full_xid;           // needed by wsrep or past it recovery
   decltype(::server_id) server_id;         // server id of orginal server
 
   xid_recovery_member(my_xid xid_arg, uint prepare_arg, bool decided_arg,
                       XID *full_xid_arg, decltype(::server_id) server_id_arg)
     : xid(xid_arg), in_engine_prepare(prepare_arg),
-      decided_to_commit(decided_arg), full_xid(full_xid_arg) , server_id(server_id_arg) {};
+      decided_to_commit(decided_arg),
+      binlog_coord(Binlog_offset(MAX_binlog_id, MAX_off_t)),
+      full_xid(full_xid_arg), server_id(server_id_arg) {};
 };
 
 /* for recover() handlerton call */