Daemon for Real-Time Data Acquisition 

Definition

Background process that processes the InfoPackages and data transfer processes assigned to it at regular intervals.

Use

The daemon receives information from the InfoPackage and data transfer process about which data is to be transferred or updated further, which PSA tables or DataStore objects are to be filled, and when a request should be closed and a new one opened.

It is used to control the transfer process for real-time data acquisition.

When you extract data, the daemon works on the basis of the list of DataSources assigned to it in the InfoPackage, extracts the data from the source systems, and transfers it to the PSA table and DataStore objects. It informs the Service API in the source system when the data for the source system has been successfully updated. When the PSA request has been closed successfully and a new delta request has been opened, the updated data is deleted from the delta queue of the source system.

When you further update data to the DataStore objects from the PSA, the daemon works on the basis of the list of sources (DataSources)and targets (DataStore objects) assigned to it in the data transfer process. It transfers data to the DataStore object. The data is written straight to the A table and the change log.

If the extraction or update is terminated, the daemon can restart the process from the point at which it was terminated. In the case of data transfer processes, you can determine the maximum number of errors that are allowed before the process is finally terminated (see also: Creating InfoPackages for Real-Time Data Acquisition).

The daemon runs in a permanent background job and only switches to "sleep" mode after performing a data transfer if there is currently no other data in the delta queue and no other data being posted to the PSA by a Web service.  If the Service API is being used to transfer the data, the RFC connection to the source system remains open. This implies that a permanent RFC connection between every source system and BI is required for real-time data transfer using the Service API.

So that the system does not use too much main memory and the RFC connection does not have to be open for too long, the daemon stops independently on a regular basis and schedules again, so that the main memory can be released and a new RFC connection is opened. This happens without having to close the request for real-time data acquisition.