High availability for the SnapCenter MySQL repository
MySQL replication is a feature of MySQL Server that enables you to replicate data from one MySQL database server (master) to another MySQL database server (slave). SnapCenter supports MySQL replication for high availability only on two Network Load Balancing-enabled (NLB-enabled) nodes.
SnapCenter performs read or write operations on the master repository and routes its connection to the slave repository when there is a failure on the master repository. The slave repository then becomes the master repository. SnapCenter also supports reverse replication, which is enabled only during failover.
If you want to use the MySQL high availability (HA) feature, you must configure Network Load Balancer (NLB) on the first node. The MySQL repository is installed on this node as part of the installation. While installing SnapCenter on the second node, you must join to the F5 of the first node and create a copy of the MySQL repository on the second node.
SnapCenter provides the Get-SmRepositoryConfig and Set-SmRepositoryConfig PowerShell cmdlets to manage MySQL replication.
The information regarding the parameters that can be used with the cmdlet and their descriptions can be obtained by running Get-Help command_name. Alternatively, you can also refer to the SnapCenter Software Cmdlet Reference Guide.
You must be aware of the limitations related to the MySQL HA feature:
NLB and MySQL HA are not supported beyond two nodes.
Switching from a SnapCenter standalone installation to an NLB installation or vice versa and switching from a MySQL standalone setup to MySQL HA are not supported.
Automatic failover is not supported if the slave repository data is not synchronized with the master repository data.
You can initiate a forced failover by using the Set-SmRepositoryConfig cmdlet.
When failover is initiated, jobs that are running might fail.
If failover happens because MySQL Server or SnapCenter Server is down, then any jobs that are running might fail. After failing over to the second node, all subsequent jobs run successfully.
For information about configuring high availability, see How to configure NLB and ARR with SnapCenter.