Bug#15851528 DUPLICATE KEY ERROR ON AUTO-INC PK WITH MIXED AUTO_INCREMENT_INCREMENT CLIENTS

Problem: Clients running different values for auto_increment_increment
and doing concurrent inserts leads to "Duplicate key error" in one of them.

Analysis:
When auto_increment_increment value is reduced in a session,
InnoDB uses last auto_increment_increment value
to recalculate the autoinc value.
In case, some other session has inserted a value
with different auto_increment_increment, InnoDB recalculate
autoinc values based on current session previous auto_increment_increment
instead of considering the auto_increment_increment used for last insert
across all session

Fix:
revert 7acdf29c
a.k.a. 7c12a9e5
as it causing the bug.

Reviewed By:
Bin <bin.x.su@oracle.com>
Kevin <kevin.lewis@oracle.com>
RB#21777

Note: In MariaDB Server, earlier changes in
ae5bc059
for MDEV-533 require that the original test in
mysql/mysql-server@1ccd472d63a042d3237a55f5827239164219ef7e
be adjusted for MariaDB.

Also, ef47b625 (MDEV-8827)
had to be reverted after the upstream fix had been backported.

mysql-test/suite/innodb/r/innodb-autoinc.result

@@ -1340,11 +1340,139 @@ SELECT * FROM t;
 i
 1
 301
-351
+601
 SHOW CREATE TABLE t;
 Table	Create Table
 t	CREATE TABLE `t` (
   `i` int(11) NOT NULL AUTO_INCREMENT,
   KEY `i` (`i`)
-) ENGINE=InnoDB AUTO_INCREMENT=401 DEFAULT CHARSET=latin1
+) ENGINE=InnoDB AUTO_INCREMENT=651 DEFAULT CHARSET=latin1
+DROP TABLE t;
+#
+# Bug#15851528 DUPLICATE KEY ERROR ON AUTO-INC PK WITH MIXED AUTO_INCREMENT_INCREMENT CLIENTS
+#
+# This test shows that the next record to be inserted is not affected
+# by a change in auto_increment_increment.
+# In addition, current value of auto_increment_increment by the client
+# that uses the existing autoinc value with be used to set next autoinc
+# value, which will be used by next client reguardless of its own session
+# setting for auto_increment_increment.
+#
+# Client 1: Insert a record with auto_increment_increment=2
+CREATE TABLE t(
+a SERIAL PRIMARY KEY,
+b VARCHAR(200)) ENGINE=InnoDB;
+SET SESSION auto_increment_increment=2;
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`),
+  UNIQUE KEY `a` (`a`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+INSERT INTO t(b) VALUES('S1');
+SELECT a,b FROM t;
+a	b
+1	S1
+# Client 2: Insert records with auto_increment_increment 2,1
+SET SESSION auto_increment_increment=2;
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`),
+  UNIQUE KEY `a` (`a`)
+) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1
+INSERT INTO t(b) VALUES('S2');
+SELECT a,b FROM t;
+a	b
+1	S1
+3	S2
+SET SESSION auto_increment_increment=1;
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`),
+  UNIQUE KEY `a` (`a`)
+) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1
+INSERT INTO t(b) VALUES('S2');
+SELECT a,b FROM t;
+a	b
+1	S1
+3	S2
+5	S2
+# Client 1: Insert a record with auto_increment_increment=1
+SET SESSION auto_increment_increment=1;
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`),
+  UNIQUE KEY `a` (`a`)
+) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1
+INSERT INTO t(b) VALUES('S1');
+SELECT a,b FROM t;
+a	b
+1	S1
+3	S2
+5	S2
+6	S1
+DROP TABLE t;
+# Autoincrement behaviour with mixed insert.
+CREATE TABLE t(
+a TINYINT AUTO_INCREMENT PRIMARY KEY,
+b VARCHAR(200)) ENGINE=InnoDB;
+SET SESSION auto_increment_increment=10;
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` tinyint(4) NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+INSERT INTO t(b) VALUES('S0'),('S1');
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` tinyint(4) NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`)
+) ENGINE=InnoDB AUTO_INCREMENT=21 DEFAULT CHARSET=latin1
+INSERT INTO t(a,b) VALUES(28,'S2');
+SET SESSION auto_increment_increment=1;
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` tinyint(4) NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`)
+) ENGINE=InnoDB AUTO_INCREMENT=31 DEFAULT CHARSET=latin1
+INSERT INTO t(b) VALUES('S3');
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` tinyint(4) NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`)
+) ENGINE=InnoDB AUTO_INCREMENT=32 DEFAULT CHARSET=latin1
+INSERT INTO t(b) VALUES('S4');
+SELECT * FROM t;
+a	b
+1	S0
+11	S1
+28	S2
+31	S3
+32	S4
+SHOW CREATE TABLE t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` tinyint(4) NOT NULL AUTO_INCREMENT,
+  `b` varchar(200) DEFAULT NULL,
+  PRIMARY KEY (`a`)
+) ENGINE=InnoDB AUTO_INCREMENT=33 DEFAULT CHARSET=latin1
 DROP TABLE t;

mysql-test/suite/innodb/t/innodb-autoinc.test

@@ -680,3 +680,63 @@ INSERT INTO t VALUES (NULL);
 SELECT * FROM t;
 SHOW CREATE TABLE t;
 DROP TABLE t;
+
+--echo #
+--echo # Bug#15851528 DUPLICATE KEY ERROR ON AUTO-INC PK WITH MIXED AUTO_INCREMENT_INCREMENT CLIENTS
+--echo #
+--echo # This test shows that the next record to be inserted is not affected
+--echo # by a change in auto_increment_increment.
+--echo # In addition, current value of auto_increment_increment by the client
+--echo # that uses the existing autoinc value with be used to set next autoinc
+--echo # value, which will be used by next client reguardless of its own session
+--echo # setting for auto_increment_increment.
+--echo #
+
+--connection default
+--echo # Client 1: Insert a record with auto_increment_increment=2
+CREATE TABLE t(
+  a SERIAL PRIMARY KEY,
+  b VARCHAR(200)) ENGINE=InnoDB;
+SET SESSION auto_increment_increment=2;
+SHOW CREATE TABLE t;
+INSERT INTO t(b) VALUES('S1');
+SELECT a,b FROM t;
+--connect(con1,localhost,root,,)
+
+--connection con1
+--echo # Client 2: Insert records with auto_increment_increment 2,1
+SET SESSION auto_increment_increment=2;
+SHOW CREATE TABLE t;
+INSERT INTO t(b) VALUES('S2');
+SELECT a,b FROM t;
+SET SESSION auto_increment_increment=1;
+SHOW CREATE TABLE t;
+INSERT INTO t(b) VALUES('S2');
+SELECT a,b FROM t;
+disconnect con1;
+
+--connection default
+--echo # Client 1: Insert a record with auto_increment_increment=1
+SET SESSION auto_increment_increment=1;
+SHOW CREATE TABLE t;
+INSERT INTO t(b) VALUES('S1');
+SELECT a,b FROM t;
+DROP TABLE t;
+
+--echo # Autoincrement behaviour with mixed insert.
+CREATE TABLE t(
+  a TINYINT AUTO_INCREMENT PRIMARY KEY,
+  b VARCHAR(200)) ENGINE=InnoDB;
+SET SESSION auto_increment_increment=10;
+SHOW CREATE TABLE t;
+INSERT INTO t(b) VALUES('S0'),('S1');
+SHOW CREATE TABLE t;
+INSERT INTO t(a,b) VALUES(28,'S2');
+SET SESSION auto_increment_increment=1;
+SHOW CREATE TABLE t;
+INSERT INTO t(b) VALUES('S3');
+SHOW CREATE TABLE t;
+INSERT INTO t(b) VALUES('S4');
+SELECT * FROM t;
+SHOW CREATE TABLE t;
+DROP TABLE t;

storage/innobase/handler/ha_innodb.cc

 /*****************************************************************************
 
-Copyright (c) 2000, 2018, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2000, 2019, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, 2009 Google Inc.
 Copyright (c) 2009, Percona Inc.
+Copyright (c) 2010, 2019, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -10529,21 +10530,6 @@ ha_innobase::get_auto_increment(
 
 		current = *first_value;
 
-		/* If the increment step of the auto increment column
-		decreases then it is not affecting the immediate
-		next value in the series. */
-		if (prebuilt->autoinc_increment > increment) {
-
-			current = autoinc - prebuilt->autoinc_increment;
-
-			current = innobase_next_autoinc(
-				current, 1, increment, 1, col_max_value);
-
-			dict_table_autoinc_initialize(prebuilt->table, current);
-
-			*first_value = current;
-		}
-
 		/* Compute the last value in the interval */
 		next_value = innobase_next_autoinc(
 			current, *nb_reserved_values, increment, offset,

storage/xtradb/handler/ha_innodb.cc

 /*****************************************************************************
 
-Copyright (c) 2000, 2018, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2000, 2019, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, 2009 Google Inc.
 Copyright (c) 2009, Percona Inc.
+Copyright (c) 2010, 2019, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -11798,21 +11799,6 @@ ha_innobase::get_auto_increment(
 
 		current = *first_value;
 
-		/* If the increment step of the auto increment column
-		decreases then it is not affecting the immediate
-		next value in the series. */
-		if (prebuilt->autoinc_increment > increment) {
-
-			current = autoinc - prebuilt->autoinc_increment;
-
-			current = innobase_next_autoinc(
-				current, 1, increment, 1, col_max_value);
-
-			dict_table_autoinc_initialize(prebuilt->table, current);
-
-			*first_value = current;
-		}
-
 		/* Compute the last value in the interval */
 		next_value = innobase_next_autoinc(
 			current, *nb_reserved_values, increment, offset,