This lab is similar to lab-009 with the addition of a read replica RDS instance, a read-only copy of the database.

 

Architecture Diagram

Overview

Follow the steps described in lab-009 with the following changes when creating the RDS instance:

• Templates: Dev/Test (free-tier won't work this time)
• DB instance identifier: lab011
• DB instance size: select Burstable classes and pick the db.t2.small
• Connectivity: set your custom VPC to be the one where your RDS instance will run; in the additional connectivity configuration - VPC security group, choose Create new and name it lab011sg; finally for the availability zone choose the one suffixed with 1a (or the first option that appears to you)
• Additional configurations: set the initial database name to lab011 and make sure automatic backups is enabled.

Step 1 - Create Read Replica

Select Actions - Create read replica.

Create the replica in a different AZ. Also, have it in the same security group lab011sg. For the DB instance identifier choose the name lab011ro. After a few minutes you should be able to see your read replica instance created.

Test and Validation

Have the phpMyAdmin configuration to first connect to the primary (master) database instance. Create a table (or modify and existing one). You should be able to do it.

Then try to connect to the read replica instead. Note that the read replica cluster has a different endpoint. You should be able to see the table modification that you did previously. Now try to modify the database (create a table or modify an existing one). You should not be able to do that now as the database is running in read-only mode.