SAP ARCHITECTURE

SAP ARCHITECTURE( Chapter2 )

DVEMBGS

Dà Dialog Work process
Và Verbose( Update Work process)
Eà  Enque
Mà  Message Service
Bà Background Work Process
Gà  Gateway Service
Sà Spool


Dialog Work process: To interact with SAP, users session of login of users (for band Work process) Minimum 2 work process Max Depends on H/W compatibility.

Verbose (Update Work process): There are two types of Update Work process
1 .Asynronous updates (Non Time Critical) Default in SAP R/3
2 .Synchronous update (Time Critical)
Updating Database Minimum 1 updates.

Enque: Lock Mechanism It is lock for the table by the user .If one user is updating one table then other user can not access the particular table as it will be locked by the user using it.The lock will be automatically released once the work is done from the existing user who is using it.

Message Server: Communication between Application Services and load balancing is done from the message server.

Central Instance: Where  message server is resides is called the central instance

Dialog Instance: When ordinary instance is running on other Application servers without Message Server is called dialog Instance.

Background Work process (BTC): For long running jobs like backup etc this process will come to the picture. While specifying it self we can use BTC option for the job process.

Gateway: Communication between the different R/3 system in the network.

Spool: Printing the SAP jobs in the network.

Layers Used in SAP are

1 Presentation Layer

Dispatcher (Assigns Work process to users Request)

2 Application Layer

3 Databases.


Dispatcher it stores the dispatcher queues to check with the permissions assigned to the users who is trying to access the Database.

Dispatcher first checks with the Task Handler then with ABAP Process, Database interface and then with SQL related this is called role in

What is Central Instance, Role in Role Out?

What is the function of Dispatcher?

Who will communicate between Application Server?


Sap on Solaris.

A user by default called Sid adm is created while installing the SAP server he is the super user of the SAP Basis,
To start SAP on UNIX platforms

1 start SAP R3à only Sap will start.
2 Start SAP DBà Only DB will Start
3 Start SAP AllàSAP+DB

To Stop SAP on UNIX platforms.

1 Stop SAP R3
2 Stop DB
3 Stop SAP ALL



To check the SAP Service is running or not is

Ps –ef grep SAP

To start a database Listener of Oracle to be started.

Login as

Su – orasid
Lsnrctl start
Exit
Then log in to
Su – sidadm
Start SAP R3

Ps –ef grep ora (to check the oracle services) to check the instances in the SAP we use dpmon instance name.