Implementing resilience in SAP Cloud SDK application
In this exercise, you will learn how to implement resilience in SAP Cloud SDK application. We will use the Mock Server instead of the actual SAP S/4HANA Cloud.
Prerequisites
For the complete execution of current exercise, you must execute the following activities first:
- Execute the following exercises:
- Creating your Pay-As-You-Go Account in SAP BTP
- Run the Mock Server on port 8081
- Complete the exercise Querying Business Partner API of SAP S/4HANA Cloud
Steps
Checkout the branch tsnestjs_v2.0_resilience in SAP Business Application Studio
Open SAP Business Application Studio.
Run the following commands in the terminal. Make sure current working directory is /home/user/projects/cloud-sdk-learning-journey.
Build and run the project
Run the application by executing the following commands in the terminal
Query the Business Partner API of SAP S/4HANA Cloud
Open the requests.http file
Click on Send Request in the requests.http file to submit the GET request for business partners
Verify that the list of business partners are returned from the Mock Server. Note: If the Mock Server is not running, make sure to run the Mock Server on port 8081 by following the prerequisites at the top
Stop the Mock Server by pressing Ctrl + C in the Mock Server project terminal
Click on Send Request in the requests.http file to submit the GET request for business partners
Start the Mock Server within 30 seconds. Notice that the resilience configuration allows the application to keep retrying with a time out of 30 seconds. Verify that the list of business partners are returned from the Mock Server since the Mock Server was started within 30 seconds
Optional: Review code in the following source files
Note
Check out the SAP Cloud SDK documentation on Executing an OData GET request using SAP Cloud SDK for JavaScript. https://sap.github.io/cloud-sdk/docs/js/tutorials/getting-started/execute-an-odata-requestCode walk-through
File name Comments on code changes business-partner.service.ts Code logic is as follows...
- Import resilience from the @sap-cloud-sdk/resilience module
- Use the middleware function to build a resilience middleware. In our example, we will use the following values
- timeout: 30 seconds
- circuitBreaker: true
- retry: true
package.json New SAP Cloud SDK modules have been installed for the project requests.http Provides various HTTP requests that can be submitted to query the Business Partner API commands.txt Provides various commands that can be run on the terminal
Optional: Manually create the project
Create or update the following files in the table below
File name Type Contents business-partner.service.ts Path: ~/projects/cloudsdk_bp_ts/src/business-partner
Modified Copy contents from here...