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