## 2.2.4  Resilience, High Availability, and Disaster Recovery
SAP has a number of processes in place to support resilience in SAP BTP, and provides different offerings so that you can support the high availability of your applications.
## How SAP Provides Resilience
SAP applies resilience principles when developing, updating, and deploying our SAP BTP applications and services.
SAP BTP provides resilience through the following:
| Processes and Offerings    | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Availability Zones         | To achieve better fault-tolerance, we deploy our services across multiple availability zones (AZs), which improves the availability of a service if there are issues with the infrastructure of one AZ. Both Kyma and Cloud Foundry utilize multiple AZs provided by the cloud providers to ensure high availability of the platform. For more information on AZs, see: • Cloud Foundry runtime: Availability Zones in the Cloud Foundry Environment [page 61]. • Kyma runtime: Standard: Amazon Web Services, Google Cloud, and Microsoft Azure. In addition to what SAP BTP offers, you can follow the Best Practices for Resilient Applications [page 54] to ensure high availability of your applications. |
| Backups                    | SAP provides platform-level backups for some foundation services. However, for most of the services, managing backups is the customers' responsibility. For more information on backups, see SAP BTP Service Configuration Backups Managed by Customers and Data Backups Managed by SAP.                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Disaster Recovery          | The SAP BTP Disaster Recovery (DR) Plan is part of the overall SAP BTP Business Continuity Plan, which includes crisis management and process continuity activities that are triggered by a declared disaster. For more information, see Disaster Recov- ery as Part of the Business Continuity Plan [page 55].                                                                                                                                                                                                                                                                                                                                                                                                |
| In-Metro Disaster Recovery | In-Metro DRis a disaster recovery solution that utilizes synchronous data replica- tion. It has been designed to protect our customers from the impact of local disas- ters that may affect a single availability zone (AZ). By deploying services across multiple AZs within a single region, In-Metro DRensures that if a disaster occurs in one AZ, the issue is contained within that zone. Meanwhile, the other unaffected AZs continue to function normally, efficiently handling incoming requests. For more information, see Disaster Recovery as Part of the Business Continuity Plan [page 55].                                                                                                      |
## Best Practices for Resilient Applications
In addition to the services offered by SAP BTP, you can follow our best practices for developing and deploying applications, which allow you to make your application running on SAP BTP stable and highly available.
## · Develop Resilient Applications
When developing your applications, apply the principles and patterns of resilient software design that fit your use case. For more information, see Developing Resilient Apps on SAP BTP. For information specifically about developing applications in the Kyma runtime, see Develop Resilient Applications in the Kyma Runtime. For situations where the load is highly available and where applications need to react by scaling, consider using Application Autoscaler. For more information, see What Is Application Autoscaler?
## · Working with Availability Zones
To benefit from the high availability mechanisms in Cloud Foundry, set up your applications with multiple instances. For more information, see Developing Resilient Applications.