Describing SAP Gateway Deployment Options

SAP Gateway was introduced in Application Server (AS) ABAP 7.00 as an optional component and became an essential part of every AS ABAP in 7.40. Watch how SAP Gateway evolved from a collection of add-ons to the one software component SAP_GWFND included in every SAP S/4HANA.

You can find a complete list of SAP Gateway add-ons on https://help.sap.com/docs/SAP_GATEWAY.

The mandatory add-ons for providing OData functionality in an ABAP system are the following:

Core

The GW_CORE add-on is literally the core of the OData runtime providing the OData libraries to perform OData requests.

Foundation (FND)

The IW_FND add-on contains additional runtime components but also the metadata store and several shared services like monitoring. It is all about managing OData services in an AS ABAP.

Business Enablement Provisioning (BEP)

The IW_BEP add-on provides all features for implementing an OData service in ABAP. Beside hand-written code, it supports the generation of OData services based on the following:

• RFC (Remote Function Call)
• BOR (Business Object Repository)
• BW (Business Warehouse)
• F4 (Value) Help

There are additional add-ons available that support further integration scenarios. These include the following:

The Generic Interaction Layer (GenIL)

GenIL is a layer connecting the business object layer (BOL) model to the appropriate database tables in the SAP Business Suite system. A software component, IW_GIL, has been created with dependencies on IW_BEP and WEBCUIF 700. It allows the integration of GenIL. Due to technical restrictions identified with the GenIL RFC APIs, only the local GenIL APIs are used.

Service Provider Infrastructure (SPI)

The Service Provider Infrastructure (SPI) is a layer for business data exposure that is independent of application and UI technology. It is used across the entire SAP Business Suite to build timeless software. It works as the backbone for different feeder technologies like user interface building block (UIBB) components, personal object worklist (POWL) components, and Adobe Forms, and it offers Floorplan Manager (FPM) integration. Many applications in various areas of SAP Business Suite use SPI.

The integration for SPI in SAP Gateway based on the add-on IW_GIL means you can potentially enable content that is already built using SPI on the SAP Business Suite system.

RFCs delivered with SPI will be used by the integration scenario.

SAP Workflow (WF)

The IW_PGW add-on contains the functionality of the Task Gateway Service, which enables access to all SAP Business Workflow items in all connected back-end systems. It is also possible to leverage BPM and third-party workflow items. To integrate BPM, you require SAP NetWeaver 7.31 SP05 or higher.

SAP HANA

SAP HANA is a product based on New DB that allows for the implementation of analytical applications that process a huge amount of data in real time.

The following different types of models, which can be created in SAP HANA DB, can be leveraged via SAP Gateway add-on IW_HDB:

• Attribute View — A reusable dimension or subject area used for business analysis.
• Analytic View — A multi-dimensional view or OLAP cube. Using analytic views, you analyze values from a single fact table that is based on the related attributes from the data foundation and attribute views.

With AS ABAP 7.40, the functionality of SAP Gateway 2.0 is part of SAP Basis. The main functionality of the four SAP Gateway 2.0 add-ons — IW_HDB, IW_BEP, IW_FND, and GW_CORE — became part of software component SAP_GWFND.

Some legacy functionality (which SAP does not recommend) has been moved to a separate add-on, IW_FNDGC (Foundation Generic Channel), which can still be deployed on top of 7.40 for backward compatibility, but should be uninstalled if the system is to be migrated to SAP S/4HANA 1511.

This table outlines which SP level of AS ABAP 7.40 or 7.50 is equivalent to which SP level of SAP Gateway 2.0 running on a release prior to 7.40. It is maintained in SAP Note 1942072 – SAP Gateway 2.0 Support Package Stack - Definition. Since SAP Gateway is shipped since 7.40 as part of the basis, the shipment is bound to the delivery of basis SPs in 7.40. This means that the number of the SP that contains the same functionality in SAP Gateway 2.0 and AS ABAP 7.40 differs.

For example, if you want to use an SAP Gateway hub running on top of AS ABAP 7.40 SP08 and you are using an SAP back-end running on top of AS ABAP 7.31, your SAP Gateway 2.0 add-ons should have SP level SP09.

Starting with AS ABAP 7.50 SP03, new developments in SAP Gateway have only been performed for the software component SAP_GWFND  in the highest AS ABAP release.

Starting with AS ABAP 7.52 SP01 up to ABAP Platform 2022, it has been decided to down-port the following structure packages and their sub-packages of the SAP Gateway Foundation framework to AS ABAP 7.51:

• /IWFND/FRAMEWORK
• /IWBEP/FRAMEWORK
• /IWCOR/TD_CSI

This includes the latest development for the SAP Gateway foundation framework for OData V4 as well as for OData V2. It does however not include the components of the Notification Channel.

Please note that:

1. In certain use-cases there might be slight variations in the functionality.
2. Not all functionalities have been down-ported (see list of down-ported software packages above).

As a result, the above mentioned sub-packages of the SAP Gateway framework in AS ABAP 7.52 SP01 are equivalent to their counter parts in the SAP Gateway framework in AS ABAP 7.51 SP05 and AS ABAP 7.50 SP11.

The same is true for higher releases to their counter parts visible in the table. The last available down-port for SAP_GWFND 750 is included in SP12. The last available down-port for SAP_GWFND 751 is included in SP09. No further down-ports are planned for these releases.

Please find more information in SAP Note 2512479 – SAP Gateway Foundation Support Package Stack Definition.

SAP Gateway can be deployed in three ways: Two types of hub deployment and the embedded deployment. The difference is, where the SAP Gateway hub framework and back-end framework are used. In Application Server (AS) ABAP 7.00 – 7.31, the hub framework comprises mainly of the add-ons GW_CORE and IW_FND, whereas the back-end framework comprises mainly the add-on IW_BEP. Since AS ABAP 7.40, the software component SAP_GWFND takes over both roles. Since then, the deployment decision is purely based on the service implementation, not the installation of add-ons.

In addition, the SAP Business Technology Platform (BTP) can be combined with all deployments. It publishes on-premise content on the Internet using SAP Build Work Zone, standard edition for SAP Fiori, or SAP Integration Suite in general.

When developing SAP Gateway in the BES using the back-end framework, the hub framework can be used on a dedicated server in front of the BES, the hub system, or FES. The services are deployed on the BESs and are registered on the FES. The communication between the FES and BES is based on RFC (Remote Function Call).

Pros

• Administration advantages (component upgrades without shutting down back-end systems, central front-end, etc.)
• Hub features (multi-origin composition, routing)
• Enhanced security for external communication

Cons

• Additional server required
• RFC communication required

This is the recommended setup for SAP Business Suite.

When using hub deployment with development in the FES, the hub and back-end framework are used in the hub or FES. In contrast to development in the BES, the service deployment takes place on the FES. This option is used if either no development is required in the BES or, in cases of releases prior to 7.40, if you are not allowed to deploy the add-on IW_BEP in the BES. In this case, you are limited to the interfaces that are accessible through the RFC in the BES.

Pros

• Administration advantages (component upgrades without shutting down back-end systems, central front-end, etc.)
• Hub features (multi-origin composition, routing)
• Enhanced security for external communication
• High release flexibility to BES

Cons

• Additional server required
• RFC communication required
• Service implementation and business logic separated by RFC

This is the recommended setup for integrating multiple BESs with different releases.

In the case of embedded deployment, development takes place in the BES, which is the same as the FES. The services are registered in the same system as they are developed. The hub framework is embedded in the BES.

Pros

• Quick and easy way to expose SAP Gateway services from a single BES
• Better performance doing all in one system

Cons

• Disadvantages when combining data from several BESs
• Downtime for BES when upgrading UI components

This is the recommended setup for SAP S/4HANA.

SAP Build Work Zone, standard edition provides a central point of access to SAP, custom-built, and third-party applications. It offers an intuitive user experience based on SAP Fiori design, a simplified access to apps and services, and a personalized home page with role-based content.

SAP Gateway services are still registered and published in the FES or BES. The data is transferred between on-premise and SAP BTP using the Cloud Connector. Users access the site(s) in the SAP Build Work Zone, standard edition and use apps accessing data in the BES.

Pros

• The SAP Gateway service are accessed in the cloud and you can leverage cloud benefits (SAP handles upgrades, scaling, security, etc.).
• The solution is integrated with other SAP BTP services.

Cons

• A service license for SAP Build Work Zone, standard edition is required.
• An Internet connection is required.

When talking about the different deployment options of SAP Gateway, in most cases we also have to take into account deployment of the SAP Fiori applications.

The hub-based deployment option is not recommended if several SAP S/4HANA systems are used because it is not possible to support different SAP S/4HANA releases in a hub deployment scenario. This is because SAP S/4HANA 1709 applications do not support SAP S/4HANA 1610 BESs and so on. Since multiple SAP S/4HANA systems cannot be upgraded simultaneously, one has to go for the embedded deployment option instead.

Deployment recommendation for SAP Fiori Front-End Server:

https://www.sap.com/documents/2018/02/f0148939-f27c-0010-82c7-eda71af511fa.html