Principle question to RFC

[Former Member]

Hello,

I have a basic question to RFC execution. Maybe somebody can give me a good hint.

Assume, we have an SAP system whose application servers are all located in Hamburg.

Furthermore there are users all over Europe, using SAPGUI.

Close to the users there are content servers to store documents and to provide fast access.

Assume that there is a 3rd party product which can convert any document into a pdf format. The functionality is located on different servers which are located close to the content servers.

There should be a background process on the SAP application server which calls an RFC on the pdf Convert Server and retrieves a document from the content server to get it converted.

Now the question: will the document be transferred to the application server to Hamburg first and from there to the pdf Convert Server? WIll the result (the pdf) also be sent to Hamburg first before it can be stored in a local content server?

Or is RFC itself so 'intelligent' to avoid these unnecessary data transfers?

I try to ask the question in general. Hopefully somebody understands the problem.

Thanks in advance.

[Former Member]

Dear Mr. Kretz,

SAP RFC is 'only' a mechanism to perform remote function invoke. Thus it makes some definition on server and client side and defines a transfer protocol.

SAP RFC itself does not define, which partners in your scenario are communicating as client or server. It is the task of the architect of your solution to define the process (of course also with respect to performance and communication overhead)

There should be a background process on the SAP application server which calls an RFC on the pdf Convert Server and retrieves a document from the content server to get it converted.
... will the document be transferred to the application server to Hamburg first and from there to the pdf Convert Server? WIll the result (the pdf) also be sent to Hamburg first before it can be stored in a local content server?

The whole thing depends on the ability of your server to certain functions.

If your Convert server is able to access docs on the content server directly by himself without ABAP "help", it can work like:

SAP AppServer -> RFC -> Convert Server <- some communication protocol -> Content Server

and will not require data transfer over Hamburg.

If Convert Server and Content server cooperate only by help of SAP ABAP, it would look like

SAP AppServer -> RFC -> Convert Server -> RFC -> SAP AppServer -> RFC -> Content Server and the whole call stack back.

 Or is RFC itself so 'intelligent' to avoid these unnecessary data transfers? 

RFC can only control, what is in his scope. That is the communication from a sender to a receiver. RFC itself cannot optimize the calls of a scenario 3 acting parties.

Hope that helps you somewhat.

Best regards