Expanding the Cloud: Enabling Globally Distributed Applications and Disaster Recovery

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As I discussed in my re:Invent keynote earlier this month, I am now happy to announce the immediate availability of Amazon RDS Cross Region Read Replicas, which is another important enhancement for our customers using or planning to use multiple AWS Regions to deploy their applications. Cross Region Read Replicas are available for MySQL 5.6 and enable you to maintain a nearly up-to-date copy of your master database in a different AWS Region. In case of a regional disaster, you can simply promote your read replica in a different region to a master and point your application to it to resume operations. Cross Region Read Replicas also enable you to serve read traffic for your global customer base from regions that are nearest to them.

About 5 years ago, I introduced you to AWS Availability Zones, which are distinct locations within a Region that are engineered to be insulated from failures in other Availability Zones and provide inexpensive, low latency network connectivity to other Availability Zones in the same region. Availability Zones have since become the foundational elements for AWS customers to create a new generation of highly available distributed applications in the cloud that are designed to be fault tolerant from the get go. We also made it easy for customers to leverage multiple Availability Zones to architect the various layers of their applications with a few clicks on the AWS Management Console with services such as Amazon Elastic Load Balancing, Amazon RDS and Amazon DynamoDB. In addition, Amazon S3 redundantly stores data in multiple facilities and is designed for 99.999999999% durability and 99.99% availability of objects over a given year. Our SLAs offer even more confidence to customers running applications across multiple Availability Zones. Amazon RDS offers a monthly uptime percentage SLA of 99.95% per Multi-AZ database instance. Amazon EC2 and EBS offer a monthly uptime percentage SLA of 99.95% for instances running across multiple Availability Zones.

As AWS expanded to 9 distinct AWS Regions and 25 Availability Zones across the world during the last few years, many of our customers started to leverage multiple AWS Regions to further enhance the reliability of their applications for disaster recovery. For example, when a disastrous earthquake hit Japan in March 2011, many customers in Japan came to AWS to take advantage of the multiple Availability Zones. In addition, they also backed up their data from the AWS Tokyo Region to AWS Singapore Region as an additional measure for business continuity. In a similar scenario here in the United States, Milind Borate, the CTO of Druva, an enterprise backup company using AWS told me that after hurricane Sandy, he got an enormous amount of interest from his customers in the North Eastern US region to replicate their data to other parts of the US for Disaster Recovery.

Up until AWS and the Cloud, reliable Disaster Recovery had largely remained cost prohibitive for most companies excepting for large enterprises. It traditionally involved the expense and headaches associated with procuring new co-location space, negotiating pricing with a new vendor, adding racks, setting up network links and encryption, taking backups, initiating a transfer and monitoring it until the operation complete. While the infrastructure costs for basic disaster recovery could have been very high, the associated system and database administration costs could be just as much or more. Despite incurring these costs, given the complexity, customers could have found themselves in a situation where the restoration process does not meet their recovery time objective and/or recovery point objective. AWS provides several easy to use and cost effective building blocks to make disaster recovery very accessible to customers. Using the S3 copy functionality, you can copy the objects/files that are used by your application from one AWS Region to another. You can use the EC2 AMI copy functionality to make your server images available in multiple AWS Regions. In the last 12 months, we launched EBS Snapshot Copy, RDS Snapshot Copy, DynamoDB Data Copy and Redshift Snapshot Copy, all of which help you to easily restore the full stack of your application environments in a different AWS Region for disaster recovery. Amazon RDS Cross Region Read Replica is another important enhancement for supporting these disaster recovery scenarios.

We have heard from Joel Callaway from Zoopla, a property listing and house prices website in UK that attracts over 20 million visits per month, that they are using the RDS Snapshot Copy feature to easily transfer hundreds of GB of their RDS databases from the US East Region to the EU West (Dublin) Region every week using a few simple API calls. Joel told us that prior to using this feature it used to take them several days and manual steps to set up a similar disaster recovery process. Joel also told us that he is looking forward to using Cross Region Read Replicas to further enhance their disaster recovery objectives.

AWS customers come from over 190 countries and a lot of them in turn have global customers. Cross Region Read Replicas also make it even easier for our global customers to scale database deployments to meet the performance demands of high-traffic, globally disperse applications. This feature enables our customers to better serve read-heavy traffic from an AWS Region closer to their end users to provide a faster response time. Medidata delivers cloud-based clinical trial solutions using AWS that enable physicians to look up patient records quickly and avoid prescribing treatments that might counteract the patient’s clinical trial regimen. Isaac Wong, VP of Platform Architecture with Medidata, told us that their clinical trial platform is global in scope and the ability to move data closer to the doctors and nurses participating in a trial anywhere in the world through Cross Region Read Replicas enables them to shorten read latencies and allows their health professionals to serve their patients better. Isaac also told us that using Cross Region Replication features of RDS, he is able to ensure that life critical services of their platform are not affected by regional disruption. These are great examples of how many of our customers are very easily and cost effectively able to implement disaster recovery solutions as well as design globally scalable web applications using AWS.

Note that building a reliable disaster recovery solution entails that every component of your application architecture, be it a web server, load balancer, application, cache or database server, is able to meet the recovery point and time objectives you have for your business. If you are going to take advantage of Cross Region Read Replicas of RDS, make sure to monitor the replication status through DB Event Notifications and the Replica Lag metric through CloudWatch to ensure that your read replica is always available and keeping up. Refer to the Cross Region Read Replica section of the Amazon RDS User Guide to learn more.