Example project showcasing a resilient multi-region app on SAP BTP powered by globally distributed Azure Cosmos DB. App was built upon the SAP Developer tutorial Create a Node.js Application via Cloud Foundry Command Line Interface and the SAP Private Link for Cosmos DB. It relies on Fastify instead of Express for a leaner setup.

This repos and associated 📝blog post shed light on the private connectivity aspect. To complete your resiliency journey, have a look at intelligent routing in this joint Microsoft+SAP Discovery Center mission and this blog post.

Create SampleDB from Quick Launch wizard in Cosmos DB on the Azure portal.

Create a SAP Private Link for Cosmos DB named cosmos-pls or rename service in manifest.yml

Run SAP Business Application Stuido or compatible IDE of your choice (I like GitHub Codespaces for ready to run environments).

git clone https://github.com/MartinPankraz/sap-nodejs-on-cosmosdb-app.git
cp templates/.env app

Maintain your cosmos credentials in the .env file. From Cosmos DB UI navigate to Settings -> Keys -> read-write Keys -> Primary Key.

cd app
npm install
npm start

Navigate to the addresses tab and enjoy the private response from Cosmos🪐☄️

Warning - when executing locally you need a connection to your SAP Private Link service (remember Cosmos is not publicly reachable!). Have a look here how to use ssh with cf.

Adjust route in manifest.yml as per SAP's recommendation in step 2.

cf push

This repos sheds light on the private connectivity aspect only. Learn more about intelligent routing in this joint Microsoft+SAP Discovery Center mission and this blog post.

Above architecture can be considered a mix of high-availability and failover concepts. How so? The SAP Private Link in each BTP CloudFoundry space is configured to be able to reach both Cosmos regions and the app layer responds to the end-user as per the intelligent routing setting (fastest, closest etc.).

Learn more about Azure IoT and Cosmos DB here.

Consider the ABAP SDK for Azure for additional interaction scenarios with Cosmos DB.

Note - Primary purpose of this Database comparison is to fuel your own investigation with no ambition to be extensive.

Lear more about choosing an API for Azure Cosmos DB here.

¹ General Purpose, Gen5 2 vCore

² Request Units need to be understood for a proper comparison. Also paritioning strategy impacting number of requests.

Note: Check the SAP Estimator and Azure Pricing Calculator to get a ballpark overview on pricing details.

As you can see there is a variety of choice of data bases for your BTP app with different capabilities and implications. The associated blog post and prototype use Azure Cosmos DB for NoSQL in a multi-region setup with provisioned throughput.

Follow this thread to stay up to date with CDS for Azure CosmosDB and SAP CAP driven by the amazing SAP Mentors. Feel free to comment under the associated blog posts or create issues here on GitHub.