How to add development server to running maxscale configuration with auto failover?

Question

I have two MariaDB 10.4.28 servers A and B that run under the control of Maxscale in auto-failover, auto-rejoin mode. I need to add a third, development, server C, which should always be in slave mode, regardless of the state of A and B, and in which, nevertheless, some data may change, and this changed data should in no case fall into on A and B. How can this be implemented?

Answer 1

You can use the servers_no_promotion parameter of the mariadbmon module to prevent some servers from being ever promoted to the Master status.

To do this at runtime, you can use maxctrl:

maxctrl link monitor <monitor-name> <server-C-name>
maxctrl alter monitor <monitor-name> servers_no_promotion=<server-C-name>