Master_ master replication on Mariadb I have a nagios application running on 2 servers, i am planning to have have master-master replication for HA. for master-slave replication, slave should be read-only. in this manner is there any pre-req for master-master replication. while doing master-master replication i ran into a lot of duplicate as both the databases are auto-increment on their own and trying to replicate each other.

can some one please help to resolve the issue.

Thanks,
To avoid the issue with duplicate keys when using auto_increment PKs, you need to configure the system variables auto_increment_increment and auto_increment_offset.

From the MariaDB Knowledgebase: AUTO_INCREMENT:


  To make master-master or Galera safe to use AUTO_INCREMENT one should
  use the system variables auto_increment_increment and
  auto_increment_offset to generate unique values for each server.


So in other words, with two masters: On master1 set auto_increment_increment=2 and auto_increment_offset=1, and on master2 set auto_increment_increment=2 and auto_increment_offset=2.