Hi, I've been working on developing a pacemaker resource-agent for mariadb semi-sync replication. There is a pull request here on github: https://github.com/ClusterLabs/resource-agents/pull/929 I would be very happy for some review (and even testing) of this resource-agent from somebody with expertise in mariadb replication. The general idea is to select the master at startup and failure as the node with the highest GTID. AFTER_SYNC is used to ensure at least one slave will have all the updates. mariadb is started with --log-slave-updates to ensure that slaves log all events, so the binary log on each node should always be complete. The parameter set on each node is as follows: SET GLOBAL rpl_semi_sync_slave_enabled='ON', \ rpl_semi_sync_master_enabled='ON', \ rpl_semi_sync_master_wait_point='AFTER_SYNC', \ gtid_strict_mode='ON', \ sync_binlog=1, \ sync_master_info=1, \ sync_relay_log=1, \ sync_relay_log_info=1; I suspect this may be overkill, but I don't have the competence to judge. I have also found that calling "SHOW SLAVE STATUS;" may take a long time to display data when the slave is very busy (typically replicating after a failure). Is there any way to make sure it doesn't block? All feedback very welcome. Best Regards, Nils Carlson