Friday, December 18, 2020

Streaming for Process Chains

User cases where a near-real-time data replication is required can be fulfilled within BW function called Streaming for Process Chains.

Feature of Streaming for Process Chains is only available on SAP BW systems of version 7.5 on HANA.

How the process chain set to streaming mode works? In contrary to synchronous mode (where loading takes in place in dialog mode) and in contrary to background mode (where one run of teh PC waits certain time before next run, and in case 1st run is not yet finished it is cancelled by the 2nd run) the streaming mode allows the “runs” of the PC are “put” to the queue. From there the PC runs are “picked” and executed without interruption of previous runs. Basically, the next run of the PC “waits” till current run is finished before new run starts.

What it takes to setup such a streaming scenario?

In case of target infoprovider regular cube the data source that feeds it needs to be flagged as real-time support. Means field REALTIME in table ROOSOURCE must be X. As this is not a case by default in biz content standard SAP delivered datasources one need to flag it manually e.g. by custom ABAP program.

As RDA (Real-time Data Acquisition) adapter set on DTP cannot be used for newer BW infoprovider – aDSO there are 2 options of leveraging ODP-SAPI Operational Data Provisioning (ODP) and SAP Landscape Transformation OPD-SLT.

In short, for OPD-SAPI a particular extractor’s Update Mode need to be set to “Direct Update”. PSA layer is not needed. Data can be visible in ODQMON queue. DTP that transfer the data is type of regular delta-DTP. Then such the DTP is included in streaming enabled PC. The PC is set like this in maintenance screen of the PC in menu: Process Chain -> Attributes -> Streaming for Process Chain.

In case of ODP-SLT this is not delta data transfer but replication of full data from source (e.g. ECC table). An ODP datasource needs to be setup in the source system with its subscription. After that regular delta-DTP is needed. Again, the DTP is used within streaming enabled PC.

In case BW system is, BW/4HANA based there is one more option to use Open ODS Views object as data target. If existing data flow leveraging the streaming is being migrated to BW/4HANA the SAP Note 2447916 described a migration process.

Technically Streaming for Process Chains are enabled by populating field STREAMING (Streaming for Process Chains) in table RSPCCHAINATTR. The STREAMING field can have following values:

blank             Normal processing, no streaming

X        Streaming on

Z        Streaming will be switched off

Y        Streaming will be switched on

W       Streaming off


More information:

Online docu for BW 7.5

Online docu for BW/4HANA

Streaming process chains

2447916 - BW4SL - Real-Time Data Acquisition (RDA)

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