This document provides an overview of SAP technical concepts including: 1) It describes the SAP R/3 system architecture with separate presentation and application layers and how transactions are handled. 2) It explains the different work processes like dialog, update, enqueue, and batch processes and their roles. 3) It discusses communication interfaces and protocols for integrating different systems as well as business APIs.

2.  What the Basis system is
 How does SAP handle a transaction
request
 Differentiating between the various
work processes
 Understanding the basic functions of
the Basis Module
SAP Technical Overview

3. SAP Technical Overview
The Software-Oriented View of R/3

4. SAP Technical Overview
The SAP R/3 System Architecture
• Implications for Application Programming
– Separate presentation and application layers implies
that when you run an application program that
requires user interaction, control of the program is
continually passed backwards and forwards between
layers.
– When a screen is ready for user input, the
presentation layer is active, and the application server
is inactive with regard to that particular program.
– As a consequence, the program logic in an
application program that occurs between two screens
is known as a DIALOG STEP.

5. SAP Technical Overview

6.  Application Layer (cont.)
› Application Server
 R/3 programs run on application servers
 The APPLICATION SERVER communicate
with the presentation components, the
database, and also with each other, using
a MESSAGE SERVER.
 Main components:
 Work Processes (Dialog, Update,
Enqueue, Batch, Spool)
 Dispatcher
 Gateway
 Message Server
SAP Technical Overview
The SAP R/3 System Architecture

8. SAP Technical Overview
Presentation . . . Internet
Application
Database
Communication
SAPGUI
SAPGUI Internet
Office
Work-
process
Work-
process
Work-
process
Dispatcher
TCP/IP
Remote SQL
IPC
Local Buffer
for R/3 Data,
DW-Objects,
ABAP-Objects

9.  Program which manages resources of the
R/3 applications
 Receives requests from user and passes
them to the corresponding work
processes
 Only one dispatcher per application
server
SAP Technical Overview

10.  Balances the workload between the
processes
 Buffer management in main memory
 Connection with the presentation level
 Organization of the communication
processes
SAP Technical Overview

11.  Responsible for executing R/3
application tasks
SAP Technical Overview
Database
Interface
Task Handler
ABAP/4
Processor
Dialog
Interpreter
Work Process

12. SAP Technical Overview
Dialog
SAP Dispatcher
Batch
Spool
Update
Enqueue
S
12
9
6
3
11 1
7 5
8 4
2
10
B
M
G
Message
Gateway
R/2 R/3
V
E

13. SAP Technical Overview
Dialog
• Responsible for the interactive
tasks of the R/3 system
• Dialog work processes execute
only one dialog step at a time
and are immediately freed for
the next user request
• Constantly switching between
users

14. SAP Technical Overview
• Responsible for executing
ABAP programs submitted
for background execution
• Batch jobs schedule the
sequence of program
execution
• Used for running long and
time consuming programs
Batch
12
9
6
3
11 1
7 5
8 4
2
10
B

15. SAP Technical Overview
• Responsible for formatting
the data for printing and
passing it to the host spool
system
• Only one spool work process
allowed per server
Spool

16. SAP Technical Overview
• Responsible for the lock
management system
• Synchronizes database access
for the multiple application
servers and work processes
• Only one enqueue process
per R/3 system to ensure
data integrity
Enqueue
E

17. SAP Technical Overview
• Responsible for making
database changes requested
by dialog and background
processes
• For better performance, this
process should be on the
database server
Update
V

18. SAP Technical Overview
• Time-critical processes are
inside V1 and less critical
ones within V2
• Error situations in
– V1 : changes rolled back and
V2 components not executed
– V2 : only changes of V2
components rolled back
Update
V

19. SAP Technical Overview
• Used by different application
servers to exchange data and
internal messages
• Routes messages, such as
update or batch job starts,
between application servers
• One message server per
system
M
Message

20. SAP Technical Overview
• Allows communication
between R/3, R/2, and
external applications
• Exchanges large amounts of
information between
application servers
• Gateway can reside on any of
the connected systems
G
Gateway
R/2 R/3

21.  Number of work processes can only be
changed after restarting the system
 Should have at least two dialog work
processes
 Need to have at least one V1 and V2
processes
 Number of spool processes cannot be
changed
SAP Technical Overview

22. SAP Technical Overview
Presentation . . . Internet
Application
Database
Communication
SAPGUI
SAPGUI Internet
Office
Work-
process
Work-
process
Work-
process
Dispatcher
TCP/I
P
Remote SQL
IPC
Local Buffer
for R/3 Data,
DW-Objects,
ABAP-Objects

23. SAP Technical Overview
TCP/I
P
Presentation . . . Internet
Application
Database
Communication
SAPGUI
Work-
process
Work-
process
Work-
process
Dispatcher
Remote SQL
IPC
Local Buffer
for R/3 Data,
DW-Objects,
ABAP-Objects
Start
Transaction
Assign User
request to
Workprocess
Fetch data from buffer/database
Re-
turn
data
for
next
step
1
2
3
4
5

24. SAP Technical Overview
Presentation . . . Internet
Application
Database
Communication
SAPGUI
Work-
process
Work-
process
Work-
process
Dispatcher
TCP/IP
Remote SQL
IPC
Local Buffer
for R/3 Data,
DW-Objects,
ABAP-Objects
1
2
3
5
6
8
Fetch data from
buffer/database
9
7
10
Assign User
request to
Workprocess
Re-
turn
data
for
next
step

25. SAP Technical Overview
Presentation . . . Internet
Application
Database
Communication
SAPGUI
Work-
process
Work-
process
Work-
process
Dispatcher
TCP/IP
Remote SQL
IPC
Local Buffer
for R/3 Data,
DW-Objects,
ABAP-Objects
1
2
3
4
5
6
8
9
7
10
11
12
13 14
Update data
on database
End transaction
Request
for update

26. SAP Technical Overview
High
Level
Low
level
SAP Technology
Communication Interface
Communication System
Mail
MAPI
SMTP
X.400
EDI
Business API
RFC
CPI-C
Q-API
IDOC
ALE
OLE

27. SAP Technical Overview
Business
Component
BAPI
ALE
BAPI
Business
Component
• Business Component - contains business
functionality
• BAPI - interface between the components
• ALE - integration of components

28. SAP Technical Overview
• Defined method of a business object
• Standardized methods allow customers to
integrate their software with R/3
• Object-oriented in nature
• BAPIs from all development platforms
that support the SAP Remote Function
Call (RFC) protocol

29. SAP Technical Overview
• Application Link Enabled (ALE) - Interface
that links different SAP systems and
external application systems
– Transport special data structures known as
IDOCS (Intermediate Documents)
• Object Linking and Enabled (OLE) -
enables desktop users to access SAP data
from many OLE client programs

31.  Hardware and Database Administration
 User and Security Administration
 Client Maintenance
 Correction and Transport System
(CTS)
 Data Dictionary
 Online Service System (OSS)
 Performance Monitoring and Tuning
SAP Technical Overview

32.  Hardware upgrades - adding memory
or servers
 Database backup and recovery
 Database optimization
 Disaster Recovery
SAP Technical Overview

33.  Create users and assign profiles
 Modify, lock and unlock users
 Develop authorizations and profiles
SAP Technical Overview

34.  Create clients
 Copy and refresh clients
 Client imports and exports
 Delete and remove clients
 Modify change options
SAP Technical Overview

35. SAP Technical Overview
R/3
System
R/3
System
R/3
System
Development Production
Quality
Assurance
Change
Request
Moving changes from one R/3 system to another

36.  OSS is a set of SAP’s online services
such as bug fixes and useful
implementation information
 OSS Notes
 Hotpacks
 Remote Connections
 Send questions to SAP
 ABAP registration
SAP Technical Overview

37.  Check database usage and storage
capabilities
 Dialog response time
 Investigate ABAP short dumps
 Optimize performance characteristics
SAP Technical Overview

38. SAP Technical Overview
• Manages the entire system - database,
application, operating system
• Collection of tools and utilities which
allow you to monitor and manage the R/3
system
• Allows monitoring of multiple R/3
systems
• Comes FREE with each SAP system

39. SAP Technical Overview
• Starting and stopping instances
• Monitoring and analyzing workload
• Alert capabilities
• Operation modes and work process
automatic reconfiguration
• Instance profile checking and
maintenance
• Logon load balancing