Call a Remote Function Module (RFC) From SAP Cloud Platform ABAP Environment – update 09/2020
As Blog Posts can’t be deleted once published and it might be – at least for the time being – good to see how an RFC call to On-Premise had to be implemented before mid Nov 2020 when the SAP Cloud NEO environment was put to rest, I’m not updating my old Blog Post, but rather write a new one.
Before I start, first some context …
SAP’s first Cloud presentation was with the NEO environment. This was SAP’s propriety Cloud runtime. Later SAP added Cloud Foundry which is an open source based industry standard platform. So we had 2 different platforms, providing different services. Before September 10, 2020, it was not possible to submit an RFC call from Cloud ABAP (Foundry based) without NEO. With NEO taken out of the picture, some NEO services were integrated into Foundry, others replaced (example: the NEO based WebIDE was replaced by the new Foundry based Business Application Studio, short BAS).
The good news is that the entire task of a Cloud ABAP RFC call got rid of several complications. Compare with my previous Blog Post and you can see that things are now almost intuitive (other than before!). An earlier prerequisite that you needed to have a Global Enterprise Account is gone as well. You can do all steps with a Trial account !
In addition you might want to check as well SAP’s updated documentation Integrating On-Premise Systems
In the following I will not use the term NEO and Foundry any more. As NEO is history, Foundry is now the one and only SAP Cloud Platform. (well, soon – after mid November 2020)
Ok – let’s start:
In a nutshell, there are the following steps to perform:
- Install SAP Cloud Connector
- Note: make sure that you have version 2.12.3 or higher installed !
- Configure your Cloud Connector to connect to your SAP Cloud Subaccount
- Grant RFC access in Cloud Connector to your on-premise SAP system(s)
- Install SAP Cloud Connector
SAP Cloud Subaccount
- Verify your active Cloud Connector connection to your On-Premise system
- Define your Destinations for the RFC call(s) in your Foundry Subaccount
Eclipse / ABAP Cloud Project
- Implement the required ABAP code to obtain the destination for your RFC call
I’m not going to cover the installation of the SAP Cloud Connector. I will just outline how to do the Cloud Connector configuration to connect to your SAP Cloud subaccount and how to add the connectivity to one on-premise SAP system with RFC.
- Add a new subaccount to the Cloud Connector
The necessary information for Region and Subaccount you can find in your Cloud Subaccount. In your Subaccount on the side menu choose Overview and find the following:
Subaccount user is the email address you use to log into the Cloud.
Description and Location ID is optional, but in case you have multiple Cloud Connector connected to your Cloud subaccount, you need to distinguish them by a Location ID. I choose SAP_FSD for Location ID and Karma as description (you will notice those names in my next screen shots)
- The result should look like this
Next select on the left menu the Cloud To On Premise to create the RFC
Follow the wizard and enter the following values:
- Back-end Type = ABAP System
- Protocol = RFC
- Connection Type – with or without load balancing (I choose without – this influences the next steps a little bit)
- Application Server and Instance number according to you backend system – check your SAP GUI for the correct values
- Virtual Application server and Virtual Instance Number – these values are defaulted from step 4. But I usually mask these values with a virtual name and instance. Later in the Cloud Subaccount your Cloud Connection overview will show the chosen virtual values
- Click Next until you reach the last step and Finish
- Now it should look like this
Click the + In the Resources section to add now the RFC function you want to make available. In the following dialog you can choose a single RFC or a generic pattern. I just make the RFC_SYSTEM_INFO available for now. Click Save and you will be here:
The On-Premise Cloud Connector configuration is completed !
Now switch to your SAP Cloud subaccount and find your connected On-Premise Cloud Connector in the Connectivity section. Notice that the Location ID is displayed in parenthesis after Master Instance and the exposed host is the masked virtual name from the above RFC config
Select New Destination and provide the data for your back end SAP system. The Proxy-Type needs to be set to OnPremise. Do not forget to maintain the Additional Properties (click New Property button in order to add/maintain)
- jco.client.ashost = < your on premise SAP host as defined in the Cloud Connector >
- jco.client.client = < SAP Client >
- jco.client.sysnr = < SAP System Instance >
If you used – as I did – a Location ID for your Cloud Connector do not forget to enter that as well.
After saving, select the Check Connection and you should see this:
The RFC connectivity is now established. Last thing to do is the ABAP code.
Go to Eclipse and create a new ABAP class and call the RFC_SYSTEM_INFO function module from the On-Premise system.
CLASS zcl_jm_rfc_sys_info DEFINITION PUBLIC FINAL CREATE PUBLIC . PUBLIC SECTION. INTERFACES if_oo_adt_classrun. PROTECTED SECTION. PRIVATE SECTION. ENDCLASS. CLASS zcl_jm_rfc_sys_info IMPLEMENTATION. METHOD if_oo_adt_classrun~main. DATA msg TYPE c LENGTH 255. DATA lv_result TYPE c LENGTH 200. TRY. DATA(lo_rfc_dest) = cl_rfc_destination_provider=>create_by_cloud_destination( i_name = |RFC_FSD| ). DATA(lv_rfc_dest) = lo_rfc_dest->get_destination_name( ). CALL FUNCTION 'RFC_SYSTEM_INFO' DESTINATION lv_rfc_dest IMPORTING rfcsi_export = lv_result EXCEPTIONS system_failure = 1 MESSAGE msg communication_failure = 2 MESSAGE msg OTHERS = 3. CASE sy-subrc. WHEN 0. out->write( lv_result ). WHEN 1. out->write( |EXCEPTION SYSTEM_FAILURE | && msg ). WHEN 2. out->write( |EXCEPTION COMMUNICATION_FAILURE | && msg ). WHEN 3. out->write( |EXCEPTION OTHERS| ). ENDCASE. CATCH cx_root INTO DATA(lx_root). out->write( lx_root->get_text( ) ). ENDTRY. ENDMETHOD. ENDCLASS.
That’s it – test your code in Eclipse with F9 and see in the Eclipse console the system info of your remote on-premise system.
Now you know how you can consume any RFC enabled On-Premise function out of your Cloud ABAP application.
One last word – as you probably agree after reading through this blog post, this is relatively simple and straight forward to enable RFC calls to an On-Premise system. And you might wonder why this blog post is here in the first place. Well, this is not the first place. See my previous blog post when NEO was around and you will agree that it used to be quite complicated (and not even possible with a Trial account). So this blog post is pretty much a follow up on the first. Not more and not less.
If you are interested in learning more about RAP (Restful ABAP Programming), then I can highly recommend the following Open SAP course: Building Apps with the ABAP RESTful Application Programming Model
thank you for the blog post! When using an Enterprise Account, I get the error message 'Destination service instance not found', although I have set up the destination in the subaccount. what could be the reason for this? Perhaps missing properties at the destination?
Hi Rouzbeh - sorry for my late reply ....
The thing is that after all this new feature was rolled out in waves. Please try again. By now it should be finally generally available
thank you! We opened an SAP ticket and were notified that our system is migrated to the new connectivity approach. Now we can connect to our backend system via an http destination but calling RFC destination always fails with the following error message:
"exception communication_failure Error when opening an RFC connection (Communication system error.)"
Since we could not find any log entries in the backend system and the cloud connector, we assume that there is a problem with initiating such a RFC call from ABAPonSCP. Any idea how to debug/fix this issue?
Thank you for this very helpful blog post. Perhaps one remark if you already used the old way.
Also, make sure that no communication arrangement to the deprecated communication scenario SAP_COM_0200 exists.
Otherwise the new scenario does not work.
is it possible to call the SAP which is deployed in cloud via RFC? Say from 3rd party software?
With the SAP Cloud Connector you can access as well RFCs in the cloud (I described the cloud to on-premise consumption. But the Cloud Connector works both ways). But the proper way - and state of the art - would be to consume/define an Odata service. Especially if data is to be made available to 3rd party consumers. The new ABAP Restful Programming model (i.e. ABAP in the cloud) allows you to define such service in a pretty simple and straight forward fashion
HI, Is there a way to connect Odata service from backend system instead of RFC FM?
of course - that is the classic (consuming RFC was a bit more complicated). You either consume the odata service via a public url:
or (preferred) you define a destination and use that one:
The rest is as usual:
Thanks for your response Jurgen. This was very helpful
Thanks Jurgen for sharing!
I am facing an error "RFC Destination S4H_RFC not found". I have setup the cloud connector and destination and the test connection is also successful . But getting error when executing the Class.
I am trying it in BTP trial account. I am not sure if it because of that or i missed something else. If you could please suggest.
Hello Jurgen Meinshausen
So I have been implementing RAP .
We have BTP as side by side with S/4 HANA On Prem .
Now it seems if we call an Odata to the on prem directly in "Create" implementation in the behavior pool it gives an error because of the "COMMIT WORK" statement somewhere in the standard code
This problem was discussed by
and the solution is to wrap the BAPI or Odata call in a RFC and call it with destination 'NONE'
So I decided to wrap my OData call in a FM and call it with destination NONE .
It gave me a dump . Screenshot below
I removed the NONE and it is working fine , rather it is going inside the FM . .
Now my question is :-
Is that adding 'NONE' -- A solution only for RAP on On-Prem , it cannot be applied to ABAP on cloud (BTP environment ) ?
What was i doing wrong . and will removing the 'NONE' solve my problem ?
If I put the OData call in a FM in SAP BTP Environment and call it without NONE will that not give me the error because of the 'COMMIT WORK' ?
Thank you for the blog.
how we can add RFC call in our implementation class in create method? We get an error while doing that.