High-Availability Oracle Databases with Amazon RDS for Oracle

Amazon Relational Database Service (RDS) for Oracle makes it easy to set up, operate, and scale Oracle Database in the cloud. With Amazon RDS, you can deploy an Oracle database in minutes with cost-efficient and re-sizable hardware capacity. The Amazon RDS Multi-AZ feature provides an enterprise class High-Availability option for all Oracle database versions and editions running in the AWS cloud.     
Multi-AZ in Amazon RDS for Oracle utilizes synchronous physical replication to keep data on a standby database up-to-date with the primary. Amazon RDS automates monitoring the primary database and protects against DB instance failures and Availability Zone (AZ) disruptions. The standby is created in a separate AZ  in the AWS region specified, giving additional protection against Data Center-wide interruptions. In the event of a planned or unplanned DB instance outage, Amazon RDS switches to the standby replica running in another AZ. Applications reconnect after Amazon RDS automatically changes the DNS record of the DB instance and the database finishes crash recovery, typically in less than 60-120 seconds.
Multi-AZ does not use Data Guard Redo Apply, so it is available for all Oracle editions, including Standard Edition, Standard Edition One, and Standard Edition Two. You can still run Multi-AZ RDS Oracle databases with Enterprise Edition (EE), but if your application does not need other EE features, you can enjoy enterprise class High-Availability at standard edition prices with Amazon RDS Multi-AZ. AWS provides low cost and up-front pricing in a pay-as-you-go-model. If you’re new to AWS, try out Amazon RDS for Oracle!
Amazon RDS Single-AZ and Multi-AZ databases can be created in 12 different AWS regions, with 5 more regions coming online in the next 12 months. Every AWS region  has at least two physically separate Availability Zones for in-region Disaster Recovery (DR). By staying in-region after failures with Multi-AZ, applications avoid a complicated and lengthy cross-region DR failover of the entire application stack. While traditional cross-region DR is available in RDS, In-region failovers allow customers to maintain their low-latency access to their applications, prevent the double-failover downtime to get back to the original region, and avoid potential data loss from Asynchronous data replication.  

This article appeared in IOUG Cloud Strategies E-Briefing, an information resource prepared by Database Trends and Applications Magazine and published in cooperation with the Independent Oracle Users Group. To subscribe, click here.