Multi-AZ deployment
If you deploy the DB instance in a Multi-AZ configuration, AWS will set up a standby database in a different availability zone. The standby instance will have synchronous updates from the primary instance. A standby instance is created and maintained by AWS. You do not have any control over the functioning of the standby database. Synchronization and automatic failover is part of the service. It is always recommended to deploy the DB instances in a Multi-AZ configuration to achieve high availability. This is one of the attractive out-of-the-box solutions that AWS provides to the customer.
To deploy a DB instance in a Multi-AZ configuration, you simply add a switch called MultiAZ with New-RDSDBInstance, as shown following:
PS C:\>New-RDSDBInstance -DBInstanceIdentifier "mywebappprd" -DBName "mywebappprd" -MultiAZ $true -StorageType gp2 -AllocatedStorage 10 -AutoMinorVersionUpgrade $true -DBInstanceClass db.t2.large -DBParameterGroupName "mywebappprd" -OptionGroupName...
