mysql - auto_increment jumps by 3 and not 1

Question

I have noticed that in my mysql server, the auto_increment setting increments by 3, for example 3 6 9 12 15 etc.

All the tables in the database are having the same problem.

I'm using mariadb 10.5 on debian 10.

Could it be because of having a 3 vps galley cluster?

MariaDB [(none)]> SHOW VARIABLES LIKE 'auto_inc%';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| auto_increment_increment | 3     |
| auto_increment_offset    | 1     |
+--------------------------+-------+
2 rows in set (0.002 sec)

Answer 1

他们把它设计成那样。你可以说这是使用 Galera 的一个限制。他们这样做是为了解决在多主集群中插入期间生成序列号作为主键时的冲突问题。

https://mariadb.org/auto-increments-in-galera/

Answer 2

如果您实际使用 Galera，则auto_increment_increment需要 3 个（或者集群中有许多节点（服务器））。

SHOW VARIABLES LIKE 'wsrep%';