Read-only Instance

Last Updated：2021-04-30

Overview

The RDS read-only instance is tailored to the read/write scenario that has a multitude of read requests rather than the write requests from the database. By creating multiple read-only instances for standard instance, it grants standard instance elastic read capacity expansion, which in turn raises the user‘s throughput capacity. The RDS read-only instance is subordinate to the RDS standard instance, and they belong to a leader-follower relationship. You must create the master instance before the creation of a read-only instance. Also, the subordinate read-only instance is automatically released if the master instance is released.

Presently, only the instance of MySQL Version supports the read/write splitting feature for this feature must be used together with the read-only instance. Both master instance and read-only instance have independent connection address, which can be automatically configured by the application, leading to splitting of data reading and writing operations. See Read-only Instance for the detailed creation of Read-only instance.

Notes:

Read-only instance keeps consistent with the master instance in version and region.

After the purchase of a read-only instance, the users need to enable read traffic undertaking feature manually. You may set enabling in your service code, or purchase Proxy Instance for enabling. Meanwhile, you may set read traffic weights for master instance and read-only instance via the two modes. See Cluster Management for details.

Read-only instance only supports “Postpaid” rather than “Prepaid”, and its billing mode may differ from the master instance.

Up to 5 master instances can be created for one master instance. If more read-only instances are needed for service, submit the Ticket.

Architecture Diagram

Master instance data are automatically synchronized to the read-only instance. Master instance may deal with the read/write requests, but read-only instance only receives read requests.

Applicable Scenarios

The read-only instance needs to be used together with a master instance, and it is applicable to the read/write scenarios (like website and Internet) in which the database has massive read requests rather than massive write requests.

Supported Database Engine

Presently, support creation of read-only instance for Baidu AI Cloud database RDS for MySQL (MySQL 5.6 and MySQL 5.7 supported)

Supported Regions

North China-Beijing, North China -Baoding, East China-Suzhou, South China-Guangzhou, Financial Central China-Wuhan, Financial East China-Shanghai, Hong Kong, Singapore.