Overview of ALE technology
The
ALE Module is best used for objects such as batch objects, that
are asynchronous in nature. It uses push technology that requires
a server listening for events. Processes called registering and
installing notify the server about what to listen to and from whom
to expect information. Registering involves using a program identifier
to give the SAP Gateway a communication point with listener threads
(servers). Function module definitions within the server interpret
data that is pushed out of SAP by providing a template for this
data.
The ALE Module uses the RFC Server Module for event handling.
The ALE Module uses WebSphere MQ queues for Transaction ID (TID)
and IDocs management. The connector checks for subscriptions when
processing the data from SAP to the connector, resulting in transactions
remaining in SAP until the collaboration is started.
- The integration broker sends a WebSphere Business Integration
Adapter business object for SAP. The business object's
data represents a processing request to the connector. The connector
converts the business object to a table format compatible with the
SAP Intermediate Document (IDoc) format. The connector uses Remote Function
Calls (RFCs) to the ALE interface to pass the IDoc data to the SAP system.
- The connector receives data representing an application event
from SAP in IDoc table format. It converts the data to a WebSphere
Business Integration Adapter business object for SAP before sending
it to the integration broker. The connector uses RFCs to the ALE
Module to receive the data from the ALE interface.
Important:
In releases of the connector prior to version 4.8.2, the
connector used collaborations, business objects, and maps to store
Transaction IDs (TIDs) and their status in the repository, and used
the local file system to store IDoc data. Version 4.8.2 of the connector
replaces the previous management of TIDs and IDoc data with the
use of WebSphere MQ queues.
Note:
Because the ALE Module uses asynchronous communication,
it cannot be used when cross-referencing is required.
