BEGINNERS GUIDE TO ABAP - Module 1 – SAP
System Overview
So we’re going to discuss the technical
architecture of a typical SAP system.
Then we’re going to move on to the landscape
architecture and just discuss why we break
our landscape into multiple systems.
Here we have a slide showing a three-tier
client server architecture of a typical SAP
system.
At the top we have the presentation server.
The presentation server is any input device
that we can use to control an SAP system.
So here we are showing the SAP GUI.
But we are not limited to just using the SAP
GUI.
We can use a web browser, mobile device or
any other form of input you can think of.
The presentation layer communicates with the
application server.
An application server is the brains of an
SAP system.
This is where all the central processing gets
done.
You can see here what’s showing the application
server isn’t just one system in itself.
Your application server can be made up of
multiple instances of the processing system.
Now the application server in turn communicates
with the database layer of the three-tier
architecture.
The database is kept on a separate server,
a separate system in itself mainly for performance
reasons but also for security as well.
It provides a separation and that’s why
we have got these three different layers in
this whole SAP system.
The presentation server communicates with
the application server.
The application server does all the processing.
It makes calls to the database.
Data is passed back to the application server.
More processing is done before the results
and then sent to the presentation server.
Now, let’s quickly discuss a typical landscape
architecture.
Now, I say typical but you’ll find that
when you work with SAP, there is no typical
(in inverted comments), landscape architecture
that most companies use.
What you do fine that is very common is you’ll
find the development system, you’ll find
the testing system, and then you’ll find
the production system.
Now, why do we have these three systems?
Well, it’s fairly straightforward.
All the development work and initial unit
testing that we do in our SAP work gets done
on a development system.
This ensures we do not affect any of the system
that is being used by the company.
Once our developments we think are good enough
to be tested by maybe an external source or
someone else within your company whose role
is to carry out testing, we move our developments
using what’s called a transport system to
the next system, which in this case is the
testing system.
On the testing system, normally no development
is done at all.
It’s just use for testing what developments
were carried out in the development system.
If everything works out and everything passes
in the test system we then use a transport
system again to move our developments or our
program changes into the production environment.
When code goes into the production environment,
that’s when it’s turned on and that’s
when it’s used within the business itself.
Now a landscape architecture is not separated
just for development purposes.
Your company can have other reasons.
That can be the quantity of data that a normal
production system holds.
It can be too great to actually be used in
the development environment because normally
your development system and your testing system
are not as large as a production system.
You only want a subset of data to test on.
There’s also the security element that you
need to look at.
More often than not, companies do not want
developers to see live production data for
data security issues.
You know, you’ve got employee data on the
system, you’ve got sales data, and you don’t
want people who are not involved in those
specific areas to actually see the live data.
So normally, your development and testing
systems have a different set of data that
they can develop and test on.
Now, I would say, the three systems we have
here are normally a minimum.
You know, you normally have got your development
system, testing system, and the production
system but it can increase to four systems.
Maybe you want a training system.
Maybe you got multiple projects running at
the same time.
So maybe you’ve got two different development
systems, you could then add up two different
test systems, you know, and then maybe a consolidation
system before it is passed to the production
environment.
This is all dependent on the company that
you're gonna be working at.
But one thing that is common is that each
system that you do have in your landscape
architecture will have its own application
server and its own database server.
This then ensures we have platform independence.
