Bug #20989615 INNODB AUTO_INCREMENT PRODUCES SAME VALUE TWICE

Problem:
=======
Autoincrement value gives duplicate values because of the following reasons.

(1) In InnoDB handler function, current autoincrement value is not changed
based on newly set auto_increment_increment or auto_increment_offset variable.

(2) Handler function does the rounding logic and changes the current
autoincrement value and InnoDB doesn't aware of the change in current
autoincrement value.

Solution:
========
Fix the problem(1), InnoDB always respect the auto_increment_increment
and auto_increment_offset value in case of current autoincrement value.
By fixing the problem (2), handler layer won't change any current
autoincrement value.
Reviewed-by: Jimmy Yang <jimmy.yang@oracle.com>
RB: 13748

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

+CREATE TABLE t1 (id INT AUTO_INCREMENT PRIMARY KEY)ENGINE=INNODB;
+# SETTING auto_increment_increment IN CONNECTION DEFAULT
+SET AUTO_INCREMENT_INCREMENT = 1;
+INSERT INTO t1 VALUES(NULL);
+SELECT * FROM t1;
+id
+1
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1
+# SETTING auto_increment_increment IN CONNECTION1
+SET AUTO_INCREMENT_INCREMENT = 2;
+SET DEBUG_SYNC= 'ib_after_row_insert SIGNAL opened WAIT_FOR flushed1';
+INSERT INTO t1 VALUES(NULL);
+SET AUTO_INCREMENT_INCREMENT = 2;
+SET DEBUG_SYNC= 'now WAIT_FOR opened';
+SET DEBUG_SYNC= 'ib_after_row_insert_step SIGNAL flushed1 WAIT_FOR opened1';
+insert into t1 values(NULL);
+# CONNECTION default
+SELECT * FROM t1;
+id
+1
+3
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=latin1
+SET DEBUG_SYNC= 'now SIGNAL opened1';
+# CONNECTION con1
+SELECT * FROM t1;
+id
+1
+3
+5
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CREATE TABLE t1(id INT AUTO_INCREMENT PRIMARY KEY)ENGINE=INNODB;
+# SETTING auto_increment_increment IN CONNECTION DEFAULT
+SET AUTO_INCREMENT_INCREMENT = 1;
+INSERT INTO t1 VALUES(NULL);
+SELECT * FROM t1;
+id
+1
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1
+SET DEBUG_SYNC = 'now SIGNAL flushed';
+# SETTING auto_increment_increment in connection1
+SET AUTO_INCREMENT_INCREMENT = 2;
+SET DEBUG_SYNC= 'now WAIT_FOR flushed';
+SET DEBUG_SYNC= 'ib_after_row_insert SIGNAL opened WAIT_FOR flushed1';
+INSERT INTO t1 values(NULL);
+# CONNECTION DEFAULT
+SET DEBUG_SYNC= 'now WAIT_FOR opened';
+SET DEBUG_SYNC= 'ib_after_row_insert_step SIGNAL flushed1 WAIT_FOR opened1';
+INSERT INTO t1 VALUES(NULL);
+# CONNECTION con1
+SELECT * FROM t1;
+id
+1
+3
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1
+SET DEBUG_SYNC= 'now SIGNAL opened1';
+# CONNECTION default
+SELECT * FROM t1;
+id
+1
+3
+5
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1
+SET DEBUG_SYNC= 'RESET';
+DROP TABLE t1;

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

+--source include/have_innodb.inc
+--source include/have_debug.inc
+--source include/have_debug_sync.inc
+--source include/not_embedded.inc
+
+# Two parallel connection with autoinc column after restart.
+
+CREATE TABLE t1 (id INT AUTO_INCREMENT PRIMARY KEY)ENGINE=INNODB;
+
+--echo # SETTING auto_increment_increment IN CONNECTION DEFAULT
+SET AUTO_INCREMENT_INCREMENT = 1;
+INSERT INTO t1 VALUES(NULL);
+SELECT * FROM t1;
+SHOW CREATE TABLE t1;
+
+--source include/restart_mysqld.inc
+
+--echo # SETTING auto_increment_increment IN CONNECTION1
+SET AUTO_INCREMENT_INCREMENT = 2;
+
+SET DEBUG_SYNC= 'ib_after_row_insert SIGNAL opened WAIT_FOR flushed1';
+
+SEND INSERT INTO t1 VALUES(NULL);
+
+connect(con1, localhost, root,,);
+SET AUTO_INCREMENT_INCREMENT = 2;
+SET DEBUG_SYNC= 'now WAIT_FOR opened';
+SET DEBUG_SYNC= 'ib_after_row_insert_step SIGNAL flushed1 WAIT_FOR opened1';
+send insert into t1 values(NULL);
+
+--echo # CONNECTION default
+connection default;
+reap;
+SELECT * FROM t1;
+SHOW CREATE TABLE t1;
+SET DEBUG_SYNC= 'now SIGNAL opened1';
+
+--echo # CONNECTION con1
+connection con1;
+reap;
+SELECT * FROM t1;
+SHOW CREATE TABLE t1;
+connection default;
+disconnect con1;
+
+DROP TABLE t1;
+
+# Two parallel connection with autoinc column without restart.
+
+CREATE TABLE t1(id INT AUTO_INCREMENT PRIMARY KEY)ENGINE=INNODB;
+
+--echo # SETTING auto_increment_increment IN CONNECTION DEFAULT
+SET AUTO_INCREMENT_INCREMENT = 1;
+INSERT INTO t1 VALUES(NULL);
+SELECT * FROM t1;
+SHOW CREATE TABLE t1;
+SET DEBUG_SYNC = 'now SIGNAL flushed';
+
+connect(con1, localhost, root,,);
+
+--echo # SETTING auto_increment_increment in connection1
+SET AUTO_INCREMENT_INCREMENT = 2;
+
+SET DEBUG_SYNC= 'now WAIT_FOR flushed';
+SET DEBUG_SYNC= 'ib_after_row_insert SIGNAL opened WAIT_FOR flushed1';
+
+send INSERT INTO t1 values(NULL);
+
+--echo # CONNECTION DEFAULT
+connection default;
+
+SET DEBUG_SYNC= 'now WAIT_FOR opened';
+SET DEBUG_SYNC= 'ib_after_row_insert_step SIGNAL flushed1 WAIT_FOR opened1';
+
+send INSERT INTO t1 VALUES(NULL);
+
+--echo # CONNECTION con1
+connection con1;
+reap;
+SELECT * FROM t1;
+SHOW CREATE TABLE t1;
+SET DEBUG_SYNC= 'now SIGNAL opened1';
+
+--echo # CONNECTION default
+connection default;
+reap;
+SELECT * FROM t1;
+SHOW CREATE TABLE t1;
+disconnect con1;
+SET DEBUG_SYNC= 'RESET';
+DROP TABLE t1;

storage/innobase/handler/ha_innodb.cc

@@ -5350,6 +5350,7 @@ ha_innobase::write_row(
 	innodb_srv_conc_enter_innodb(prebuilt->trx);
 
 	error = row_insert_for_mysql((byte*) record, prebuilt);
+	DEBUG_SYNC(user_thd, "ib_after_row_insert");
 
 	/* Handle duplicate key errors */
 	if (auto_inc_used) {
@@ -10461,6 +10462,37 @@ ha_innobase::get_auto_increment(
 	ulonglong	col_max_value = innobase_get_int_col_max_value(
 		table->next_number_field);
 
+	/** The following logic is needed to avoid duplicate key error
+	for autoincrement column.
+
+	(1) InnoDB gives the current autoincrement value with respect
+	to increment and offset value.
+
+	(2) Basically it does compute_next_insert_id() logic inside InnoDB
+	to avoid the current auto increment value changed by handler layer.
+
+	(3) It is restricted only for insert operations. */
+
+	if (increment > 1 && thd_sql_command(user_thd) != SQLCOM_ALTER_TABLE
+	    && autoinc < col_max_value) {
+
+		ulint	prev_auto_inc = autoinc;
+
+		autoinc = ((autoinc - 1) + increment - offset)/ increment;
+
+		autoinc = autoinc * increment + offset;
+
+		/* If autoinc exceeds the col_max_value then reset
+		to old autoinc value. Because in case of non-strict
+		sql mode, boundary value is not considered as error. */
+
+		if (autoinc >= col_max_value) {
+			autoinc = prev_auto_inc;
+		}
+
+		ut_ad(autoinc > 0);
+	}
+
 	/* Called for the first time ? */
 	if (trx->n_autoinc_rows == 0) {
 

storage/innobase/row/row0mysql.c

@@ -1241,6 +1241,8 @@ row_insert_for_mysql(
 
 	row_ins_step(thr);
 
+	DEBUG_SYNC_C("ib_after_row_insert_step");
+
 	err = trx->error_state;
 
 	if (err != DB_SUCCESS) {

storage/xtradb/handler/ha_innodb.cc

@@ -11731,6 +11731,37 @@ ha_innobase::get_auto_increment(
 	ulonglong	col_max_value = innobase_get_int_col_max_value(
 		table->next_number_field);
 
+	/** The following logic is needed to avoid duplicate key error
+	for autoincrement column.
+
+	(1) InnoDB gives the current autoincrement value with respect
+	to increment and offset value.
+
+	(2) Basically it does compute_next_insert_id() logic inside InnoDB
+	to avoid the current auto increment value changed by handler layer.
+
+	(3) It is restricted only for insert operations. */
+
+	if (increment > 1 && thd_sql_command(user_thd) != SQLCOM_ALTER_TABLE
+	    && autoinc < col_max_value) {
+
+		ulint	prev_auto_inc = autoinc;
+
+		autoinc = ((autoinc - 1) + increment - offset)/ increment;
+
+		autoinc = autoinc * increment + offset;
+
+		/* If autoinc exceeds the col_max_value then reset
+		to old autoinc value. Because in case of non-strict
+		sql mode, boundary value is not considered as error. */
+
+		if (autoinc >= col_max_value) {
+			autoinc = prev_auto_inc;
+		}
+
+		ut_ad(autoinc > 0);
+	}
+
 	/* Called for the first time ? */
 	if (trx->n_autoinc_rows == 0) {
 

storage/xtradb/row/row0mysql.c

@@ -1254,6 +1254,8 @@ row_insert_for_mysql(
 
 	row_ins_step(thr);
 
+	DEBUG_SYNC_C("ib_after_row_insert_step");
+
 	err = trx->error_state;
 
 	if (err != DB_SUCCESS) {