SAP BASIS FANDAS BASIC

 

PRELIMINARY FANDAS FOR SAP BASIS

• What is ERP?

Answer : Its called Enterprise Resource Product.

SAP ERP : In that Product there is multiple modules like BASIS,CRM,ABAP etc.

Sap Erp is divided into 2 products i.e CRM and SCM.

• Types of SAP architecture for BASIS people:

R/1 : Main frame systems 

R/2 : Client Server Architecture

R/3 : Client+App server+ Database (Client is in presentation layer ,App server is in Application layer , and DB server is in database layer).

• Full form of BASIS?

 Business Application Systems Integrated Solutions 

• Basis are divided into 2 part for business i.e below

 i) Implementation : a) Hardware Sizing 

                                 b) Operating system and Database.

                                 c) Remote Desktop

                                 d) Download the software's from SAP service market place.

                                 e) Installation

                                 f) Post Installation steps 

ii) Support : a) Level1 i.e Monitoring sap systems

                    b) Level 2 i.e Trouble shooting,Working on tickets,Ticketing tools,Job tools.

                    c) Level 3 i.e Critical issues.

From Business prospective there are SLA (Service level Agreement) on tickets.

• Architecture of the SAP R/3:

 

In the picture SAP GUI is application layer and PAS and AAS is in application layer and Database is in database layer.

Need to remember that Message Server always will be in PAS i.e Primary application server.

MSG server : Message Server
GTW server : Gateway Server
WP : Work process
ENQ server : Enqueue server
PAS : Primary Application Server
AAS : Additional Application Server
DB : Database

• What is Dispatcher ?

 SAP dispatcher is the control agent which manages the resources for R/3 applications.
Mainly dispatcher works for load balancing in process management.

•  What is SAP Work Process?

An Sap application server has dispatcher , all the request are coming from sap gui or front end landed in sap dispatcher.Then the dispatcher transfers the requests to work process.Then the WP execute the desired requests.

• Types of Work Process in SAP system?Back

          1) DIALOG WP                   

          2) BACKGROUND WP
          3) UPDATE WP
          4) SPOOL WP
          5) ENQUEUE WP

1) Dialog Wp: Dialog work process fulfill all the requests  for execution of dialog steps trigger by an active user.Every dispatcher need at least 2 dialog wp and maximum 98.

2) Background Wp: Back Ground wp execute programs that run without interacting with the user.
We need at least 2 Background Wp and maximum 98.

3) Update Wp: Update wp execute update requests.we need at least 1 update wp in dispatcher.
we can configure multiple update wp in a dispatcher.

4) Spool Wp : Spool work process pass sequential data flows on to printers.we need at least 1 spool wp.

5) Enqueue Wp : The Enqueue wp administers the lock table in the shared memory.The lock table contains the logical database locks of the abap run time environment of the SAP system.Only one enqueue wp need for for each system.

• What is ABAP Message Server ?

Message Server handles communications between the distributed dispatchers within AS ABAP systems,thereby enabling scalability of several parallel application servers.
Message server is configured only once per SAP system.

• What is Gateway Server?

 The Internet gateway server enables the communication between 2 SAP systems and also SAP server to Outside and vice versa.
There is one per dispatcher .

• What is ICM (Internet Communication Manager)?

 An ICM enables the communications between SAP systems through HTTP protocol.The ICM receive the requests from users and forward them to SAP systems (ABAP+JAVA) .In dual stack system (ABAP+JAVA) its recognize the request whether it came for ABAP system or AS JAVA system and process them accordingly.It can also process HTTP request from SAP system to any Web Server and send the response back to SAP server.
Need to remember that we can configure 1 ICM process per application server.


 





The following process are there in AS JAVA server:

1. The Dispatcher distributes the incoming requests to server process.
2. The server process executes the java applications.Every Server process can process a large number of requests in parallel.For each dispatcher there is at least once server process and can be up to 16 server process.
3. The Java message services manages a list of java dispatchers and server process.It is responsible for the communication within java run time environment.
4. The java enqueue services manages the logical locks that are set by executed java application program in a server process.

• Types of SAP Net weaver AS :

         Architecture SAP 7.0 and lower





















Architecture SAP 7.1 and Higher.

 Changes we can see in SAP netweaver 7.1 and higher :

1. The CI  was renamed to PAS (Primary application server)
2. The Dialog Instance is renamed as AAS (Additional Application Server)
3. The Java Dispatcher is replaced by ICM .
4. The SDM process is discontinued.
5. The Java central instances has compromises a gateway process.