Back-End Adapter 

Purpose

In a mobile scenario, the Data Orchestration Engine (DOE) downloads data from the back-end system and distributes this data to mobile devices based on their requirement. In addition, DOE also uploads the data from the mobile devices to the back-end system to ensure that the back-end system validates and updates the data. To enable this data exchange with the back-end system, DOE must integrate with the back-end systems. This integration between the DOE and the back-end systems is achieved using back-end adapters.

Implementation Considerations

Back-end adapters are plug-ins in the DOE that allow the DOE to connect to back-end systems using BAPI wrappers. The BAPI wrappers in SAP NetWeaver Mobile can be used in the DOE with minor changes to improve performance.

Features

Homogenization

This service performs the transformation between the back-end schema definition and the data object schema definition, as the definitions can be different. This is a custom service and can be developed for each of the back-end adapter types. You can develop this service as an ABAP program that transforms a BAPI structure to a data object structure.

Extract

This service is used to extract data from the back-end system in the following situations:

·        Initial Load

After the initial setup, you need to download data from the back-end system to the consolidated data store (CDS) in the DOE. This process is called initial load. The back-end adapter provides an extract service to perform the initial load for each business object.

·        Delta Load

When the business objects are modified in the back-end system, you need to download the modified objects from the back-end system to the CDS in the DOE. This process is called delta load and can be achieved by using any of the following methods:

¡        Push

The back-end system consolidates the delta changes and pushes the data to the back-end adapter. The extract service then calls the inbound handler in the DOE to process the data.

¡        Pull

The DOE requests data from the back-end system. The extract service of the adapter pulls the data from the back-end system and calls the inbound handler in the DOE to process the data. This type of load slows performance.

Inbound Adapter

This service performs the following activities:

Protocol Homogenization

This service performs the transformation between the back-end message protocol and the data object message protocol. The standard inbound service is provided to convert a BAPI that is imported as a data object

Ordering and Queuing of Messages

When the data is pushed from the back-end system, the sequence of the messages is maintained in the queue.

Outbound Adapter

The DOE core services call this service to request for data from the back-end system. This service primarily contains a request to extract or validate data. This request is made through an instance of a data object message that contains information in the message header to distinguish between a validate request or an extract request.

Validation

This service ensures that the messages exchanged with the back-end systems are validated. You can mark one of the back-end systems as a master system for a particular type of data object.