01_SAP System Architecture

What is Basis?BC010_01.1

What Does SAP R/3 Do?

ProductionPlanning

HumanResources

Sales &Distribution

MaterialsManagement

FinancialControlling


SAP R/3 Basis Software Is the “Middleware” of the R/3 System

ExternalComputing

environment

R/3 Basiscomponents

(“middleware”)

Request for computing resources

UNIX


Hardware and Operating System

SAP R/3 Basis Software

ProductionPlanning

MaterialsManagement

Finance andControlling

Sales andDistribution

Human Resources

The R/3 Basis System


Logical Groupings or “Layers” of SAP R/3 Components

The Database Layer

Those SAP R/3 software components that specialise in the management , storage and retrieval of data form the database layer.

The Application LayerThose SAP R/3 software components that specialise in processing business applications form the application layer.

The Presentation LayerThose SAP R/3 software components that specialise in interacting with end-users form the presentation layer.


The Presentation Layercollects user input andcreates process requests.

The Application Layeruses the application logic ofSAP programs to collect andprocess the process requests.

The Database Layerstores and retrieves all data.

Communication

Three-Tiered Client/Server Architecture “Logical Layers”


reside in: reside in:reside in:

Physical Distribution of R/3’s Logical Layers

Database Layer components

Application Layer components

Application servers:Specialised systems multiple CPUs and vast amounts of RAM.

Presentation servers:Systems capable of providing a graphical interface.

Presentation Layer components

Database servers:Specialised systems with fast and large hard drives.


Client/Server Defined

PC Software Program SAP Client/Server Software

MS Excel Components

A BB CC

Presentation Layer

Application Layer

Database Layer


Physical Distribution of R/3’s Three Layered Client/Server Architecture

The Database Layer components are installed on one high-end database server.

The Application Layer components are installed across one or more high-end servers.

Presentation Layer components are installed across many PCs.


R/3’s Client/Server Configurations- Centralistic

Centralistic

Computer“A”

Presentation Layer Application Layer Database Layer


R/3’s Client/Server Configurations-Distributed Presentation


Distributed Presentation

Computer

“A-n”

Computer“A-2”

Computer“A-1”

Computer“A”

Computer“B”


Two-tier Client/Server

Computer“B”

R/3’s Client/Server Configurations-Two-tier Client/Server

Computer

“A-n”

Computer

“A-2”

Computer

“A-1”

Computer

“A”



Three-tier Client/Server

R/3’s Client/Server Configurations-Three-tier Client/Server

Computer

“C”

Computer

“A”

Computer

“A”

Computer

“A”

Computer

“A”

Computer

“B”

Computer

“B”

Computer

“B”



Computer

“A-1”

Computer

“A-2”

Computer

“A-n”

Computer

“A”

Computer

“B-1”

Computer

“B-n”

Computer

“B”

R/3’s Client/Server Configurations- Multi-Tier, Co-operative Client/Server

Multi-tier, cooperative Client/Server

Computer

“C”

Computer

“C-n”



R/3’s Client/Server Configurations- Multi-Tier, Co-operative Client/Server - ALE


Computer

“C-n”Computer“B-n”

Computer“B-1”

Computer“B-1”

Computer“A”

Computer“A-1”

Computer“A-2”

Computer“A-n”

Computer

“C”


Example components of SAPGUI:

• SAP Business Graphics• SAP Hierarchy Graphics• SAP Pushbutton Graphics• SAP Statistical Graphics• SAP Gantt Chart Graphics• SAP HPGL Display• SAP Network Graphics• SAP Portfolio Graphics• SAP Bar Chart Graphics• SAP Structural Graphics

SAPGUI: The Presentation Layer Software

Presentation Layer Software: SAPGUI


Application Layer Software: R/3 Runtime System

Presentation Layer Software: SAPGUI

1 to 2 Kilobytes

Easily achieved over a WAN

Exchanging Data between the Presentation and Application Layers


Business Transactions

Business Transaction FD02 “Change customer information”

Screen 1

Screen 2

Complete transaction ?


Business Transactions and the R/3 Runtime System

Screen 1

Screen 2

R/3 Runtime System

… LOCK business object “XYZ” then,… Prepare to “ROLLBACK” if necessary


Processes

ProcessA Process is essentially a program. Each process has memory and accessto system resources.


Threads

Process

Thread 1 Thread 2 Thread 3

A Thread is the actual component of a process that is executing at one time. Each thread is capable of completing a different task thatits process requests.


The O/S Kernel

CPU

Process

OS Kernel

ProcessProcess


Work Processes and the Dispatcher

SAP

Diaolg Update Enqueue Spool Background

CPUOS Kernel

SAP DispatcherA component of the SAP Kernel called the Dispatcher must manage process access to the OS kernel.


The R/3 Runtime System

Dispatcher

Dialog Update Spool Background

Application Application Server “A”Server “A”

Dispatcher

EnqueueDialog Update Spool Background

Application Layer Application Layer ononDatabaseDatabaseServerServer

DispatcherApplication Application Server “B”Server “B”Dialog Update Spool Background


Dispatcher

USER 1

USER 2

USER 3

USER 4

Dispatcher


Update Enqueue Spool Backgroundor Batch

Dialog

Work Processes


Dispatcher

Presentation level

Application level

Various types of processing requests

Request

queues

EnqueueUpdate SpoolDialog Batch

Dispatcher in Action


Dispatcher


Request

queues

Process RequestUser: Fred JonesActivity: Read data XYZScreen: 1

Inside the R/3 Runtime System


Update Enqueue Spool Backgroundor Batch

Dialog

Dispatcher

SAP R/3 Transactions are written in ABAP, SAP’s 4th generation interpreted programming language.

SAP R/3 Runtime Systemis written in ANSI-C

The Code Behind R/3


Work

Pro

cess

TaskHandler

DYNPRO Processor

ABAP Processor

mem

ory



Request queuesDispatcher


Process RequestRead data “XYZ” orWrite data “XYZ”



Transaction

Screen 1.I want to run a customer report for customer 00017.

Screen 1

Screen 2.I only want to include data in my report that pertains to orders that were filled within the last 2 months.

Screen 2

Screen 3. But only for product XYZ.

Screen n.

Reading Data in the R/3 System


Transaction

Screen 1 Screen 2 Screen n.

Request queuesDispatcher

ProcessRequest 1

ProcessRequest 2

ProcessRequest 3



R/3 R/3 BufferBufferss

Sh

are

d M

em

ory

S

eg

men

ts

RequesRequest t QueueQueuess

Dia

log

TaskHandl

erDYNPABAP

mem

or

y

Screen 1 Screen 2 Screen n.Tra

nsacti

on

Process Requests

Requesteddata retrievedfrom the R/3Buffers

AVAILABLED

ialo

g

TaskHandler

DYNP

ABAP

mem

ory

BUSY

DispatcherDispatcher

Dia

log

TaskHandler

DYNP

ABAP

mem

ory

BUSY



Exte

nd

ed

Mem

ory

Extended Extended Memory Memory ManagerManager

R/3 R/3 BuffersBuffers S

hare

d M

em

ory

S

eg

men

ts

DispatcherDispatcher

Request Request QueuesQueues

The process request for the next screen iscopied down.

The data retrieved for the last screenis stored in extended memory in an areacalled the usercontext.

Dia

log

TaskHandl

erDYNP

ABAP

mem

ory

AVAILABLE



SAP Logical Unit of Work (SAPLUW)SAP Logical Unit of Work (SAPLUW)

Transaction


Update

+

SAP Logical Unit of Work



Transaction +

Update

Handled by:

Handled by:

Handled by:

Handled by:

Dialog B Dialog C UpdateDialog A


Distribution of a Business Transaction Across Multiple WPs


Asynchronous Updating: The Online Phase

VBLOGVBLOG

Dialog CDialog BDialog A


Transaction +

Update


Database Commit

Database Commit

Database Commit

Write Write Write

The Online Phase of an update ends here.


UpdateDialog CDialog BDialog A


Transaction +

Update


Database Commit

Database Commit

Database Commit

VBLOGVBLOG

Asynchronous Updating: The Posting (Update) Phase

Read

The Posting Phase of an update starts here.


Posting RoutineData U1 Screen 1 of 3



VBLOG

SA

PLU

WS

AP

LU

W

Dialog C

Dialog B

Dialog A

VBLOG Records


Errors during Posting (Update) Phase


Posting Routine Data U1 Screen 1 of 3



Handling of Error Situations(U1 Termination)

VBLOG

SA

PLU

WS

AP

LU

W

Update

UU 11..ROLLBACK

..ROLLBACK

..Ignored

Dialog C

Dialog B

Dialog A


Handling of Error Situations

(U2 Termination)

Update

SA

PLU

WS

AP

LU

W




VBLOG

UU 22

ContinueDialog C

Dialog B

Dialog A


Dialog

EnqueueMessage Service

Lock Request

Lock Table

The Enqueue Work Process


Background

Background Job ABackground Job A

Step # 1Step # 1Step # 2Step # 2

Defining a background job.

The Background Work Process


Print

O/SSpooler

The Operating Systemspooler assumes the print queue management.

The Spool Work Process


Service A

Process A1 Process A2Online

Requesting a particular function or “service”.

A Service


The Message Service

Online

Enqueue

Lock Request

Lock TableMessage

Service


The SAP Gateway Service

An external R/3 System

Gatewayserver

SAP Gateway Service

Communication to an external R/3 System


CPI-C API

Work Process Work Process

Example: Work process communication


Remote Function Calls

Non SAP system

Example: Communication with an external system


EDI Architecture

MM(Customer)

IntermediateDocument Type

EDI Subsystem

Communication

SD(Vendor)

IntermediateDocument

EDI Subsystem


An SAP Instance

SAP Dispatcher

Work Processes

SAP Instance

Operating System

TCP/IP Software


An SAP Central Instance

EnqueueWork Process

SAP Dispatcher

Work Processes

SAP Central InstancePeripheral Instance “A”

Message Service

Peripheral Instance “B”

Operating System

TCP/IP Software


An SAP System

SAP Dispatcher

Work Processes

SAP Instance

Operating System

TCP/IP Software

DATABASEEnqueque

Work Process

SAP Central Instance Message

Service

SAP Dispatcher

Work Processes

Operating System

TCP/IP Software

SAP Dispatcher

Work Processes

SAP Instance

Operating System

TCP/IP Software


SAP Servers

SAP Server/ Instance8 Dialog Work

Processes3 Background Work

Processes1 Spool Work

ProcessesSAP Server/ Instance3 Dialog Work

Processes8 Background Work

Processes1 Spool Work

Processes


The GTC Training System

• 8 Dialog• 3

Background• 1 Spool

Instance LOC A

JulioOracle

Database

Louis• 8 Dialog• 3

Background• 1 Spool

Instance LOC B

Clint

• 2 Dialog• 2

Background• 3 Update• 1 Enqueue• 1 Spool• Msg Service• Gateway

Central Instance

Louis

Date post:	27-Nov-2014
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01_SAP System Architecture

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