Here while learning about
mainframe architecture its operating systems, history how it evolved and
features of mainframes I noticed few similarities comparing to SAP NetWeaver
architecture.
There are few points of view
where I found some similarities between the two.
With regards to architecture - From this point of view,
it all goes back to early days of SAP. When they introduced R/2 software
(Enterprise Resource Planning software) which at the time (approximately in
1979) was only available on the mainframes (before R/2 there was an R/1 which
was batch processed based system). When they started to develop R/3 (launched
in 1992) they needed to migrate to client/server architecture. The R/3
inherited many components of the R/3 like tables, UI in form of DynPros, ABAP
programming language, batch job management, etc. which at the end formed Basis platform
of the R/3 (Basis Component - BC). By this way many of architecture principles
that they used on mainframe got to new technology that was the client/server.
Later the Basis Component of R/3 was transformed to NetWeaver (2013)
by adding Web Application Server and other components and rest is history.
Controlling of user interactions – in R/3 SAP had to
simulate functionality of 3270 terminal screens of R/2. That’s how function key
like F1, F3, F11, F12 made to SAP GUI of R/3 and subsequently even to most
recent version of SAP GUI. The purpose of function keys followed an IBM standard
for application user interfaces (mainframe user interfaces). See user screens examples of R/2 and R/3 here.
F1 Help
F3 Save and Quit
F10/F11 Shift left/right
F12 Cancel (Quit without saving)
Batch
job management - SAP NetWeaver job
management has its roots in jobs on an IBM mainframe. The concept is quite
similar. Mainframe’s JES (Job Entry Subsystem) has similar principles that we
can find in SAP’s NetWeaver like:
job class, input, conversion, processing, output (output goes to spool), etc.
Software
development – ABAP was introduced in case of R/2 (so on
mainframe) software and it is supported by SAP stack also today (of course ABAP
has evolved since and has many features of modern programming languages. It started
as a report language influenced by COBOL which is predominant programming language
even today. There are many similarities between the two. E.g. language statements
like: END-IF, END-PERFORM, ADD, MOVE-CORRESPONDING, WRITE etc.
In standard SAP NetWeaver
ABAP stack based installations there is ABAP program called ROIUHSTRUTIL. It is
available in the newest version of the NetWeaver – 7.5. The program itself appears to be COBOL to ABAP conversion,
string processing support tool.
Storage
Management - Data sets are basically files in Linux. This term is
used in both worlds, mainframe and in case of SAP there is a language statement
in ABAP called OPEN
DATASET.
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