Applications that are mission-critical to the business need to be available all the time, as even a minor outage can impact the business. To provide high availability, SAP BTP services such as SAP Launchpad service support Availability Zones (AZ) with multiple instances of an application deployed in multiple AZs, and if there is an issue in one AZ, the other AZ serves the users. But this is bounded to a single region and might not be enough in case of planned outages like major application upgrades or unplanned outages such as a region-wide outage due to a natural disaster.
This can be addressed by implementing the multi-region architecture where a service can be deployed across multiple regions. With the help of a DNS-based load balancer such as Azure Traffic Manager, the health of the services can be monitored, and the requests can be routed to the healthy service. So, if one region’s launchpad service is down, the other region’s launchpad service will be served to the users.
Check the blog post for an overview of ‘SAP BTP Multi-Region reference architectures for High Availability and Resiliency‘.
Multi-region High Availability for the SAP Launchpad service
SAP Launchpad service is a central point of access to applications from SAP systems such as SAP S/4HANA, SAP Ariba or other 3rd party systems for the end-users. As this is the only point of access to the business users, an outage might cause an impact on the customer’s business. Hence it is crucial to provide high availability (HA) for this service using multi-region architecture to have uninterrupted access with fewer to no outages.
In this setup, you must subscribe to the SAP Launchpad service in two subaccounts from different regions and are mapped to a custom domain URL, e.g., ‘https://launchpad.customdomain.com’ using SAP BTP Custom Domain service. Azure Traffic manager plays an important role in monitoring the health of these two Launchpad services and routes the user’s requests to the healthy Launchpad service. In such a setup, if one region’s Launchpad service is unavailable, the other region’s launchpad service will be served to the users.
High-level Implementation Steps
- SAP Launchpad service subscription in two subaccounts from different regions.
- Custom domain URL as the single point of access to the SAP Launchpad service
- Configure & map the custom domain to the Launchpad service routes using SAP BTP Custom Domain service.
- Azure Traffic Manager as the intelligent component to monitor the health of the services and route the user requests in the event of failover to the available service in another region.
- SAP Launchpad services can be synchronized automatically leveraging SAP BTP Cloud Transport Management service. (Transport Fiori Launchpad sites on SAP BTP using SAP Cloud Transport Management service | SAP Blogs)
While implementing this architecture, consider the subscription costs for the two SAP Launchpad services and ensure that the applications are always in sync in the two subaccounts. Applications deployed on SAP BTP also need to be available in other subaccounts. If they have DB access specific to the subaccount, they might not work out-of-the-box but will work well without additional developments with the federated sources such as SAP S/4HANA. For a seamless switch in failover scenarios, it is required to configure SSO.
We have detailed step-by-step documentation for this scenario if you want to try it.
You can watch this demo that showcases the failover scenario for the SAP BTP Launchpad service with multi-region architecture.
I hope this has helped to understand how to implement the multi-region high availability for your SAP BTP Launchpad service. You can use this same setup to route traffic based on the geographical location to reduce the latency or to show region-specific content, or you could simply use this as a load balancer to distribute the increased traffic across regions.
Let us know if you have tried a similar setup in your landscape or would like to learn more about this to implement in your landscape.
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