Accelerating Business Processes with SAP AIF Synchronous Interfaces

Document Overview

This document explains how synchronous messages can be handled within the SAP AIF (Application Interface Framework), including approaches for error handling and monitoring. The example described below covers a scenario where a WebService is deployed on an SAP S/4HANA system, implemented as an ABAP Proxy class, and the inbound request is processed through AIF.

To follow this document effectively, you should have basic familiarity with ABAP and the AIF framework.

Synchronous vs Asynchronous Processing

Before we move into the solution, it is important to understand what synchronous communication means.

Synchronous messaging:
The sender sends a request and waits for a direct response before continuing to the next step in the process.

Asynchronous messaging:
The request is sent and the sender does not wait for completion or response. Processing continues independently.

In business processes, synchronous communication is commonly used when immediate validation or confirmation is required, such as validating a customer number during an order process.

Problem Overview in SAP AIF

From a design perspective, SAP AIF does not store payloads for synchronous WebService messages. This behavior is caused by how SAP WebService processing works. Persistence is not performed for synchronous Proxy calls, which means that no data is stored in the SRT_MMASTER table.
For reference, see SAP Note 1575707.

As a result:

• Message payloads are not available in AIF monitoring

• In case of failure, the support team cannot view the inbound data

• This impacts troubleshooting and traceability

This issue specifically affects scenarios where external systems call SAP via ABAP Proxy Web Services.

You can use the XML Persistence Engine for storing synchronous messages, but the standard configuration runs in the background, which means it does not return a direct synchronous response. Therefore, adjustments are needed to achieve both:

• Real-time synchronous response

• Error visibility and monitoring in AIF

For more background, refer to the official AIF documentation:
https://help.sap.com/viewer/p/SAP_APPLICATION_INTERFACE_FRAMEWORK

Technical Solution in AIF

To address the issue, we need to understand how AIF manages message storage and processing through its engines:

Common persistence classes include:

Selected Configuration

For this solution we use:

• Application Engine: WebService (standard)

• Persistence Engine: XML

The proxy implementation must explicitly trigger AIF processing using the AIF Proxy Enabler. In the example below, the standard exception class CX_MDC_STANDARD_MESSAGE_FAULT is used to capture errors returned by AIF actions:

TRY.
    /aif/cl_enabler_proxy=>process_message(
        is_input               = ls_input
        iv_exception_classname = 'CX_MDC_STANDARD_MESSAGE_FAULT' ).
CATCH cx_mdc_standard_message_fault INTO DATA(lo_fault).
    LOOP AT lo_fault->standard-fault_detail ASSIGNING FIELD-SYMBOL(<fs_fault>

Persistence Step

After AIF processing, the Message GUID returned by the AIF Enabler class can be retrieved and stored. This enables standard AIF monitoring to show full payload details, including in case of failure.

The required persistence logic relies on standard AIF classes, such as /AIF/CL_ENABLER_XML, without custom development.