High availability of AWS RDS services

As a PAAS service of AWS, RDS has been well developed, basically covering all OLTP RDBMS databases.

As a cloud service provider, PAAS service has a great advantage in the convenience of using the database. It can be deployed in 10 minutes according to your own needs with the click of a mouse.

However, for the stability of the service, PAAS has more restrictions on the operation and management of many databases than self-installed databases.

Today we mainly list the support of several RDS in Multi-AZ (available in multiple regions) and Multi-Region (disaster recovery across regions).

This test is only for Beijing region and Ningxia region of China.

1. Currently available RDBMS database in Ningxia region.

2. Postgresql can support Multi-AZ setting.

3. Postgresql can also support the creation of Replica slave across Region

4. SQL Server can use Multi-AZ, which is based on SQL Server's Always On. This requires that the Region contains three availability zones AZ before it can be created. Ningxia region can be created, but Beijing has only two AZ, so it is impossible to create Multi-AZ.

5. SQL Server does not support cross-region replication.

6. Oracle can also be Multi-AZ

7. Oracle can create replica, that is, Dataguard, but does not support cross-Region DG.

8. As the representative of open source database, Mysql,AWS naturally supports Multi-AZ and Multi-Region.

9. Cross-region replica

10. Aurora can create Replica. Since Aurora is a concept of shared storage between master and slave nodes, replica across Region is naturally not supported.

11. Aurora's Multi-AZ is highly available based on replica. When something goes wrong with Master, replica will take over the Master service. Not the slave concept of Mysql's Multi-AZ.

Note: there is no direct connection between Beijing region and Ningxia region, that is, cross-Region data synchronization of customers' EC2 or other services can only be transmitted through the public network or their own direct connect. But inside AWS, dedicated lines are provided for the master-slave synchronization of RDS and the Cross Region Replication function of S3, and a certain amount of bandwidth is provided for each account. In normal business scenarios, this bandwidth is sufficient. If you have special bandwidth requirements, you can contact AWS Support for assistance.