Readiness check in ARC
With readiness check in Amazon Application Recovery Controller (ARC), you can gain insights into whether your applications and resources are prepared for recovery. After you model your AWS application in ARC and create readiness checks, the checks continually monitor information about your application, such as AWS resource quotas, capacity, and network routing policies. Then, you can choose to be notified about changes that would affect your ability to fail over to a replica of your application, to recover from an event. Readiness checks help make sure, on an ongoing basis, that you can maintain your multi-Region applications in a state that is scaled and configured to handle failover traffic.
This chapter explains how to model your application in ARC to set up the structure that enables readiness checks to work, by creating a recovery group and cells that describe your application. Then, you can follow the steps to add readiness checks and readiness scopes so that ARC can audit readiness for your application.
After you create readiness checks, you can monitor the readiness status of your resources. Readiness checks help you to ensure that a standby application replica and its resources match your production replica on an ongoing basis, reflecting the capacity, routing policies, and other configuration details of your production application. If the replica doesn't match, you can add capacity or change a configuration so that your application replicas are aligned again.
Important
Readiness checks are most useful for verifying, on an ongoing basis, that application replica configurations and runtime states are aligned. Readiness checks shouldn't be used to indicate whether your production replica is healthy, nor should you rely on readiness checks as a primary trigger for failover during a disaster event.
Set up a resilient recovery process for your application
To use Amazon Application Recovery Controller (ARC) with AWS applications that are in multiple AWS Regions, there are guidelines to follow to set up your applications for resilience, so that you can support recovery readiness effectively. Then, you can create readiness checks for your application and set up routing controls to reroute traffic for failover. You can also review the recommendations ARC provides to about your application's architecture that can improve resiliency.
Note
If you have an application that is siloed by Availability Zones, consider using zonal shift or zonal autoshift for failover recovery. No setup is required to use zonal shift or zonal autoshift to reliably recover applications from Availability Zone impairments.
To move traffic away from an Availability Zone for load balancer resources, start a zonal shift in the ARC console or in the Elastic Load Balancing console. Or, you can use the AWS Command Line Interface or AWS SDK with zonal shift API actions. For more information, see Zonal shift in ARC.
To learn more about getting started with resilient failover configurations, see Getting started with multi-Region recovery in Amazon Application Recovery Controller (ARC).