Hi All, I've recently had an issue when I've needed to add <resource_name>_mysql_master_IP to hosts in a MySQL HA cluster as I needed to move a running cluster onto a VPN.
It seems <resource_name>_REPL_INFO is only set when a resource is promoted, so as a test, I: * Put the system in maintenance mode * Manually removed the <resource_name>_REPL_INFO from the CIB * Added the appropriate <resource_name>_mysql_master_IP attributes for each node. * Manually configured MySQL to be using IP based replication * Then took the cluster out of maintenance mode. The replication continued ok, but as predicted the <resource_name>_REPL_INFO was not populated. When putting the current master into standby, the slave was promoted correctly and the <resource_name>_REPL_INFO populated correctly. HOWEVER, while doing this, I noticed in the code, if the master hostname changes, the replication for the slave is restarted at the master position, not the slave position. See: https://github.com/ClusterLabs/resource-agents/blob/master/heartbeat/mysql#L535 Why on earth would we ever do this? This seems rife for a disaster of lost writes. I feel we should only ever be using the current slave position as the start position for a CHANGE MASTER command. Can somebody set me straight on this matter? I feel maybe I'm missing something significant. Cheers, Les _______________________________________________ Users mailing list: Users@clusterlabs.org http://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
