Many OpenStack services use MySQL as the default database server. Load balancing is necessary when any of the nodes is overloaded or fails due to some reason. To manage this failover situation, we need to exploit a solution called high availability as follows. To make this MySQL database server highly available, it requires configuring the distributed replicated block service as explained in the following sections.
Replications of data between disks are done with DRDB; in our case, the
/dev/sdb disk on
controller_2. We need to edit the configuration file of DRDB with the following command:
sudo gedit /etc/drbd.conf
The configuration file looks like the following: ...