connection node_2;
connection node_1;
show variables like 'auto_increment%';
Variable_name	Value
auto_increment_increment	3
auto_increment_offset	3
create table t4 (c1 int primary key auto_increment) engine=innodb;
show variables like 'auto_increment%';
Variable_name	Value
auto_increment_increment	3
auto_increment_offset	3
alter table t4 add (c2 varchar(50));
show variables like 'auto_increment%';
Variable_name	Value
auto_increment_increment	3
auto_increment_offset	3
DROP TABLE t4;