In-Process and Out-of-Process Communication 

Use

There are two different methods for transferring RFC data from the VM container. One is out-of-process communication, in which the Java data and ABAP data are situated in different work processes. The other is in-process communication, in which the Java data and the ABAP data are situated in one and the same work process. Each of these two methods has its own VMC driver.

Architecture

 

In-processcommunication is required for data transfer between the Java and ABAP environment in SAP NW AS if you want this transfer to take place within the same work process.

The out-of-process method is used both for internal communication in the Application Server and for communication with an external server. Here, data is transferred simultaneously between both Java and ABAP and between two different work processes.

Features

The table below shows the RFC types that are supported depending on the role of the VM container:

VM Container: Supported RFC Types

Channel	RFC Role		RFC Type
	Client	Server	sRFC	aRFC	tRFC	qRFC	RFC with Dialog
In-Process	VMC-Java	VMC-ABAP	x
	VMC-ABAP	VMC-Java	x
Out-Of-Process	VMC-Java	ABAP	x		x
	VMC-Java	External	x		x
	VMC-ABAP	ABAP	x	x	x	x	x
	VMC-ABAP	External	x		x
	ABAP	VMC-ABAP	x	x	x	x	x
	ABAP	VMC-Java	x
	External	VMC-ABAP	x		x		x
	External	VMC-Java	x

Explanation:

●     sRFC: Synchronous RFC

●     aRFC: Asynchronous RFC

●     tRFC: Transactional RFC

●     qRFC: Queued RFC

●     RFC with dialog: RFC with SAP GUI support (dialog step)