SAP Basis - Overview

 

Introduction to BASIS

 

  What is BASIS?

SAP BASIS stands for Business Application System Integrated Solutions. It is a platform that acts as an interface between DB, OS, Communication  protocols and Business Applications that is various SAP modules like FI, HR, MM, SD, SCM etc.

Roles of BASIS Administrator:

·                Handling Day-to-Day running applications.

·                System Monitoring for smooth performance.

·                Performance Tuning.

·                SAP License maintenance.

·                User Administration/Maintenance.

·                Role & Authorization.

·                Client Administration.

·                Transport Management.

·                Background job scheduling, monitoring etc.

·                Database Management.

·                Applying SNOTES.

·                System copy, refresh etc.

What is SAP Instance and SID?

    SID stands for System Identifier or SAP System Identifier. It is a 3 digit code in a particular server. The rule for naming convention are:

1.        It should be of 3 digits only.

2.        It should be in upper case.

3.        It can be a combination of both letter and character.

 Eg:-

Suppose we have 3 system landscape i.e. Development, Quality, & Production.

·               Case 1 & 2: System can be identified as DEV, QAS, PRD

·               Case 3: For Development: D01, D02

                                   For Quality Sys   : Q01, Q02

                              For Production    : P01, P02

Note: Try to keep SID simple so that It could be identified easily.

SAP Instance: Any resource (Device/Hardware) which is used within the landscape is known as instance. Basically it is a collection of resources such as Memory, Work Process, Gateway, Dispatcher.

 

SAP Instance is a combination of 2 digits between 00-99.

 Note:- (75 and 99 are reserved for TCP/IP use)

       SAP instances are numbered because there can be multiple resources within the same system(SID) at a single point of time. It differentiates between multiple instances in a single host. There are 3 type of instances:

1.            Dialog Instance

2.            Central Instance

3.            Database Instance

                                                                    fig1: help.sap.com

Dialog Instance: It is present in the Application layer and it is used for maintaining load on the server when needed. Application layer can have more than 1 Dialog instance for an individual system.

Central Instance: It can work as a Dialog Instance with some extra responsibilities. As the Central instance contains Message and enqueue servers the Dialog instance communicates with the central instance before requesting a database with a message server. Locking table is managed by Central Instance using enqueue servers.

Database Instance: It is responsible for accepting the request from the Central Instance. The Central Instance sends requests to DB Instance as per the request of the user.