100

sm61  :  For background tasks,special job server groups are created as a logon group in transaction SM61.

sm51: display application servers.

sm37:  obtain an overview of the background jobs in your sap system.

solman_workcenter: Work centers support task-specific actions,and are designed to offer fast access to important and frequently used functions.

Queued RFC(qRFC) is an extension of tRFC. It also ensures that individual steps are processed in sequence.
bgRFC is the successor to tRFC and qRFC.

The instance number is user to obtain the relevant sapgw$$ service for communication with the target system gateway.This service is contained in the

services file in the operating system and the communication port is defined there. Example: If the instance number is 11, the service is sapgw11 and the port

is 3311.

An( ABAP ) instance only ever has one(ABAP)dispatcher. An instance requires a minimum of two dialog work processes. Otherwise it is not possible to start it.
Several instances can be installed on the same host.
During a logon session, the assignment of the user to the instance is unique. Only during a new logon can the user possibly  be assigned to a different

instance by the message server.
When logging on using a logon group, the ABAP message server is always contacted first in order to identify the instance with the best performance within

the selected logon group. The load information is determined by a report on each instance,which is run automatically erery five minutes. This report saves

the information in a special memory area in the message server,which the SAP GUI can then use to request the best current instances of a group. To avoid

the best current instances of the group becoming overloaded with new logons whenever a large number of users attempt to logon within the five minute

period, the load information is updated for each instance after ervery fifth logon.(P33)

The ABAP message server has two main tasks:
   1. Distribution of logon load through logon groups.
   2. Enable certain work process types to be used across all instances.

1. The instance that,together with the database, forms a functional SAP system is also known as the central instance.
2. SAP systems use work process multiplexing technology to process user requests.   Put differently,this means that there is not a one-to-one assignment of

user to dialog work process for the entire duration of the logon.

Note: In a system with an ABAP Central Services instance, there is no longer a central instance because the defining processes( enqueue work process and

message server ) have been relocated. This means that besides the ASCS instance, there are only the dialog instances . (P69)

Before Stopping the SAP System:
1. Check the status of Logged-on users SM04
   Background processing SM37 and Batch Input SM35: Are jobs actives or planned? Are jobs triggered by external systems?
   Update SM13
   External connections
2. Send a system message SM02.

(P101)The profile files are automatically created during installation. After installation is complete,the profile files are stored at operating system level in the

directory: \usr\sap\<SID>\SYS\porfile. This directory can be read by all instances of an SAP system using the share or mount technique.

Note:  In the TPFYPROPTY table, all dynamically switchable profile parameters are identified with the Dynamic indicator. (P103)

[P124] The Control Panel (RZ03) allows you to monitor the instances and the operation modes and provides functions to :
  1. Check the status of all instances and of the operation modes
  2. Start and stop the instances.
  3. Manually switch operation mode.
  4. Display an overview of the work processes.
  5. Switch to the Alert Monitor.

[P133] The sequence of the profile parameters read from the specified locations by the system are : Kernel  Default profile  Instance profile.
In Instance profile you can change the number of background work processes.
You can use transaction RZ10 to check the consistency of individual profiles.
Setting up operation modes are : Create operation modes, Assign instances, Distribute work processes, Maintain time table.