Note : S/4HANA Cloud supports debugging only for SAP Support (Internal and partners in support) with corresponding access rights .

What is SOAP service? What is OData service? What is the difference?
SOAP(Simple Object Access Protocol) is an XML based protocol. It is platform independent and language independent. By using SOAP, you will be able to interact with other programming language applications.
OData provides communication via RESTful(REpresentational State Transfer) APIs that relies on a stateless, client-server, cacheable communication protocol.

For differences between SOAP and OData services refer the link:
https://answers.sap.com/questions/12516400/odata-vs-web-services.html

Scenario:
This blog contains information with respect to debugging services (SOAP and OData) connecting the S/4HANA cloud environment with Ariba network (either direct connectivity or via Cloud Interface Gateway(CIG)), in the Cloud environment: 42K,1ZM,2NV.

Prerequisites:
1) Recognize the communication user
    Refer blog  : Understanding Communication user in Ariba integration with S/4HANA (1ZM,42K)

2) Recognize the SOAP or OData service responsible for the interaction
    Refer blogs: Tracking the OData services triggered from Ariba to S/4 HANA cloud system
                      :  Identify SOAP services responsible for interaction between Ariba and S4 HANA systems (1ZM ,2NV,42K scenarios)

Steps:

After recognizing the Communication user, SOAP and OData service, perform the following steps:

  1. Debugging SOAP service:
    1. Run T-code SE80 -> Enterprise Service Browser -> Open -> Web Service Definition tab -> Web service name

b.  Select Referenced Object -> Implementing Class -> Select the relevant method 

      c. Place an external breakpoint inside the method


After placing the breakpoint ,trigger the application that connects the S/4 system with Ariba for debugging.

  2. Debugging OData service :

    a) Run T-code /N/IWFND/MAINT_SERVICE -> Find the OData service name to be debugged -> Click on Service Implementation -> 

   b) Select Data Provider Class -> Based upon the activity being performed (CRUD) place the breakpoint in the relevant method .


 

Note:

It is mandatory to place breakpoint for the communication user and also switch on system Debugging to trigger the breakpoint from external sources .
 Go to Utilities -> Settings -> ABAP Editor -> Debugging -> Provide the Communication User ID and uncheck "Current application server only" and switch on system debugging

System Debugging :

To switch on System debugging

Run '/H' and press 'Enter' go to Settings->System Debugging On/Off


 

Debugging an interaction between S/4HANA and Ariba is useful to understand the services and the functionality behind every operation performed either on S/4 or Ariba end.