Why?
Read Replica provides you extra read-only power, so you can direct your heavy load SELECT (OLAP) queries to the read replica, while the main RDS cluster can serve your critical OLTP transactions.
How?
To create a MySQL read replica in Amazon Web Services (AWS) using Amazon Relational Database Service (RDS), you can follow these steps:
- Sign in to the AWS Management Console and navigate to the RDS dashboard.
- In the navigation pane, click on the "Instances" menu item.
- Select the instance that you want to use as the source for the read replica.
- From the "Actions" dropdown menu, select "Create read replica".
- In the "Create Read Replica" dialogue box that appears, you can specify the following options:
- The instance identifier for the read replica. This should be unique within your AWS account.
- The instance class for the read replica. You can choose from a range of instance sizes based on your performance and capacity needs.
- The storage type and size for the read replica. You can choose between magnetic and SSD storage, and specify the size in gigabytes.
- The availability zone for the read replica. This determines the geographical region where the read replica will be located.
- The security group and VPC for the read replica. You can use the same security group and VPC as the source instance, or choose different ones.
- Click "Create read replica" to create the read replica. It will be created as a new RDS instance, and will be automatically replicating data from the source instance.
You can monitor the progress of the read replica creation process by checking the "Status" column on the RDS dashboard. When the status of the read replica changes to "available", it is ready to use.
Keep in mind that read replicas are designed to be used for read-only workloads, and you cannot write to them directly. Any writes to the source instance will be replicated to the read replica, but you cannot write directly to the read replica.
Keep Performing, Moshe Kaplan
